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DEVELOPMENT AND APPLICATION OF MODIFIED HYLAURONIC ACID DERIVED NANOPARTICLES FOR IMAGE GUIDED SURGERY AND DRUG DELIVERY BY TANNER KINKADE HILL A Dissertation Submitted to the Graduate Faculty of WAKE FOREST UNIVERSITY GRADUATE SCHOOL OF ARTS AND SCIENCES in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Biomedical Engineering May, 2015 Winston-Salem, North Carolina Approved By: Aaron M. Mohs, PhD, Advisor and Chair Lissett R. Bickford, PhD Nicole H. Levi, PhD Frank C. Marini, PhD, Thaddeus J. Wadas, PhD
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Page 1: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

DEVELOPMENT AND APPLICATION OF MODIFIED HYLAURONIC ACID

DERIVED NANOPARTICLES FOR IMAGE GUIDED SURGERY AND DRUG

DELIVERY

BY

TANNER KINKADE HILL

A Dissertation Submitted to the Graduate Faculty of

WAKE FOREST UNIVERSITY GRADUATE SCHOOL OF ARTS AND

SCIENCES

in Partial Fulfillment of the Requirements

for the Degree of

DOCTOR OF PHILOSOPHY

Biomedical Engineering

May, 2015

Winston-Salem, North Carolina

Approved By:

Aaron M. Mohs, PhD, Advisor and Chair

Lissett R. Bickford, PhD

Nicole H. Levi, PhD

Frank C. Marini, PhD,

Thaddeus J. Wadas, PhD

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DEDICATION AND ACKNOWLEDGEMENTS

I would first like to thank my advisor Dr. Aaron M. Mohs for the extensive support,

guidance, and encouragement he has provided, without which this work would

not have been possible. Throughout the time spent in his lab, Dr. Mohs has had

an incredibly supportive, innovative, and driving role as my advisor and this has

been critical in terms of learning, productivity, and well-being. I would also like to

thank the other members of my committee, Dr. Frank C. Marini, Dr. Nicole H.

Levi, Dr. Lissett R. Bickford, and Dr. Thaddeus J. Wadas for their thoughtful

critiques and advice how to improve this research. Amanda Davis, Dr. Steve

Kridel, and Dr. Todd Lowther also deserve special thanks for their work on the

Nano-ORL collaboration, as without their contribution the work would not have

come to completion. Dr. Colleen Webb and Dr. Joseph von Fischer both deserve

thanks for their incredible influence on my choice of a scientific career and the

research training they provided me with during my time at Colorado State

University. I would also like to give a very special thanks to Dr. Kenneth

Klopfenstein of the Colorado State University Department of Mathematics, whose

influence on me personally and scientifically cannot be overstated. Dr. K. was a

wonderful mentor to me, his classes and teaching not only taught me calculus

but about the world and myself as well. I would also like to thank the Mike and

Lucy Robbins family for their generous financial support of my graduate career

through their fellowship. Finally, I would like to thank my parents, whose support

has been a significant boon to me during my graduate career.

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TABLE OF CONTENTS

DEDICATION AND ACKNOWLEDGEMENTS............................................... i

TABLE OF CONTENTS................................................................................. ii

LIST OF FIGURES AND TABLES................................................................. viii

LIST OF ABBREVIATIONS............................................................................ x

ABSTRACT.................................................................................................... xiii

CHAPTER 1: INTRODUCTION…………………………………………………. 1

1.0 Nanoparticles in Medicine and Biomedical Research…….……………… 1

Liposomal Nanoparticles……………………………………………………….... 3

Metallic Nanoparticles…………………………………………………………… 5

Quantum Dots……………………………………………………………………. 7

Polymeric Nanoparticles………………………………………………………… 8

Hyaluronic Acid Derived Nanoparticles……………………………………….. 9

2.0 Biodistribution and Toxicity of Nanoparticles…………………………….. 16

The Reticuloendothelial System……………………………………………….. 17

Tumor Structure and the Enhanced Permeability and Retention Effect…… 17

The Mechanical Environment………………………………………………….. 19

Nanoparticle Properties Affecting Delivery……………………………………. 19

Size………………………………………………………………………………… 20

Shape……………………………………………………………………………... 22

Charge…………………………………………………………………………….. 23

Surface Modification...................................................................................... 24

Toxicity……………………………………………………………………………. 26

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3.0 Clinical Imaging in Oncology………………………………………………. 27

X-ray and Computed Tomography…………………………………………….. 28

PET and SPECT………………………………………………………………… 30

Magnetic Resonance Imaging…………………………………………………. 31

Non-fluorescence Optical Imaging…………………………………………….. 32

Non-fluorescence Intraoperative Tumor Detection…………………………... 33

4.0 Fluorescence Imaging and Image Guided Surgery……………………… 34

The Clinical Need for Image Guided Surgery………………………………… 35

Physics and Chemistry of Fluorescence……………………………………… 37

Fluorescence Imaging in Cancer……………………………………………… 39

Fluorescence Image Guided Surgery Instrumentation……………………… 45

5.0 Fatty Acid Synthase in Cancer……………………………………………. 47

Biology of FASN………………………………………………………………… 47

FASN Inhibitors and ORL………………………………………………………. 49

6.0 Conclusions…………………………………………………………………. 51

CHAPTER 2: SYNTHESIS OF NOVEL HYALURONIC ACID DERIVED

NANOPARTICLES………………………………………………………………

53

1.0 Introduction…………………………………………………………………. 53

2.0 Materials and Methods…………………………………………………….. 54

Materials…………………………………………………………………………. 54

Aminopropyl-1-pyrenebutanamide Synthesis……………………………….. 54

Aminopropyl-5β-cholanamide Synthesis…………………………………….. 56

Conjugation of 5βCA or PBA to HLA…………………………………………. 56

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Conjugation of ODA to HLA…………………………………………………… 57

Hydrophobic Conjugate Characterization……………………………………. 58

Confirmation of NP Formation………………………………………………… 58

3.0 Results and Discussion…………………………………………………… 59

Hydrophobic Moiety Synthesis and Conjugation to HLA…………………... 59

4.0 Conclusions………………………………………………………………… 65

CHAPTER 3: IN VITRO CHARACTERIZATION OF INDOCYANINE

GREEN-LOADED NANOPARTICLES………………………………………..

67

1.0 Introduction…………………………………………………………………. 67

2.0 Materials and Methods…………………………………………………….. 68

ICG Loading into Nanoparticles………………………………………………. 68

Nanoparticle Characterization………………………………………………… 69

NanoICG Serum Stability……………………………………………………… 69

Photostability……………………………………………………………………. 70

NanoICG Interaction with Serum Proteins…………………………………… 70

In Vitro Cellular Uptake of NanoICG………………………………………….. 71

Cytotoxicity………………………………………………………………………. 72

Statistical Analysis……………………………………………………………… 72

3.0 Results and Discussion……………………………………………………. 73

Physical, Chemical, and Optical Characterization…………………………... 76

NanoICG Interaction with Serum Proteins…………………………………… 82

In Vitro Cellular Uptake of NanoICG………………………………………….. 85

Cytotoxicity………………………………………………………………………. 87

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3.0 Conclusions………………………………………………………………… 89

CHAPTER 4: TUMOR UPTAKE, BIODISTRIBUTION, AND POTENTIAL

FOR IMAGE GUIDED SURGERY OF NANO-ICG IN XENOGRAFT

TUMOR........................................................................................................

91

1.0 Introduction…………………………………………………………………. 91

2.0 Materials and Methods…………………………………………………….. 92

iRFP Transfection of MDA-MB-231 Cells……………………………………. 92

Initial NIR Fluorophore Enhanced IGS……………………………………….. 93

Extension of In Vivo Biodistribution and IGS……………………………….... 94

Tissue Phantoms……………………………………………………………….. 95

Statistical Analysis……………………………………………………………... 96

3.0 Results and Discussion…………………………………………………... 96

Initial In Vivo Investigation Using Subcutaneous Flank Tumors………….. 96

Image Guided Surgery………………………………………………………… 99

Further In Vivo Investigation with Orthotopic Breast Tumors and an

Additional Contrast Agent………………………………………………………

102

Analysis with Tissue Mimicking Phantoms…………………………………... 109

4.0 Conclusions…………………………………………………………………. 113

CHAPTER 5: APPLICATION OF HYALURONIC ACID DERIVED

NANOPARTICLES TO DRUG DELIVERY…………………………………...

114

1.0 Introduction………………………………………………………………….. 114

2.0 Materials and Methods……………………………………………………... 115

Materials………………………………………………………………………….. 115

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Drug Loading and Quantification……………………………………………… 116

Physical Characterization………………………………………………………. 118

FASN Inhibition………………………………………………………………….. 118

Inhibition of Lipid Synthesis……………………………………………………. 118

Cytotoxicity………………………………………………………………………. 119

Chemical Stability………………………………………………………………. 120

Mitochondrial Respiration Assays…………………………………………….. 121

Statistical Analysis……………………………………………………………… 122

3.0 Results and Discussion…………………………………………………… 123

Drug Loading and Physical Characterization………………………………... 123

Inhibition of FASN and Lipid Synthesis………………………………………. 125

Cytotoxicity of Nano-ORL……………………………………………………… 127

Chemical Stability………………………………………………………………. 132

Mitochondrial Respiration Assays…………………………………………….. 134

4.0 Conclusions………………………………………………………………… 140

CHAPTER 6: CONCLUSIONS AND FUTURE DIRECTIONS……………... 141

Summary of NanoICG Studies……………………………………………….... 141

Biodistribution and ICG Release to Serum Proteins……………………….... 142

An IGS-Specific Animal Model is Needed……………………………………. 145

Extension of NanoICG to SLN Mapping……………………………………… 146

Summary of Nano-ORL Studies……………………………………………….. 147

Diameter of Nano-ORL…………………………………………………………. 148

In Vivo Testing of Nano-ORL………………………………………………….. 149

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HLA Remains a Suitable Biopolymer for NP Research……………………… 150

Conclusions………………………………………………………………………. 150

WORKS CITED…………………………………………………………………... 152

APPENDIX………………………………………………………………………... 180

CURRICULUM VITAE…………………………………………………………… 186

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LIST OF ILLUSTRATIONS AND TABLES

Figure 1-1…………………………………………………………………………….2

Figure 1-2……………………………………………………………………………10

Table 1-1……………………………………………………………………………..14

Figure 1-3…………………………………………………………………………….38

Figure 1-4…………………………………………………………………………….41

Figure 1-5…………………………………………………………………………….45

Figure 1-6…………………………………………………………………………….49

Figure 1-7…………………………………………………………………………….51

Scheme 2-1…………………………………………………………………………..55

Figure 2-1…………………………………………………………………………….61

Figure 2-2…………………………………………………………………………….62

Table 2-1……………………………………………………………………………...63

Figure 2-3…………………………………………………………………………….65

Figure 3-1…………………………………………………………………………….74

Table 3-1……………………………………………………………………………...75

Figure 3-2…………………………………………………………………………….77

Figure 3-3…………………………………………………………………………….78

Figure 3-4…………………………………………………………………………….79

Figure 3-5…………………………………………………………………………….80

Figure 3-6…………………………………………………………………………….81

Figure 3-7…………………………………………………………………………….83

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Table 3-2……………………………………………………………………………...84

Figure 3-8…………………………………………………………………………….85

Figure 3-9…………………………………………………………………………….87

Figure 3-10…………………………………………………………………………...88

Figure 4-1…………………………………………………………………………….98

Figure 4-2…………………………………………………………………………….99

Figure 4-3…………………………………………………………………………….101

Figure 4-4…………………………………………………………………………….104

Figure 4-5…………………………………………………………………………….106

Figure 4-6…………………………………………………………………………….108

Figure 4-7…………………………………………………………………………….110

Figure 5-1…………………………………………………………………………….124

Figure 5-2…………………………………………………………………………….126

Figure 5-3…………………………………………………………………………….129

Figure 5-4…………………………………………………………………………….131

Figure 5-5…………………………………………………………………………….133

Figure 5-6…………………………………………………………………………….135

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LIST OF ABBREVIATIONS

HLA: hyaluronan/hyaluronic acid

NIR: near infrared

ICG: indocyanine green

IGS: image guided surgery

ORL: Orlistat

NP: nanoparticle

DLS: dynamic light scattering

AFM: atomic force microscopy

BSA: bovine serum albumin

PM: positive margin

FASN: fatty acid synthase

DOX: doxorubicin

PEG: poly(ethylene glycol)

RES: reticuloendothelial system

AuNP: gold nanoparticle

CT: computed tomography

MRI: magnetic resonance imaging

SPIO: superparamagnetic iron oxide

QD: quantum dot

ECM: extracellular matrix

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MW: molecular weight

EPR: enhanced permeability and retention

ROS: reactive oxygen species

PET: positron emission tomography

SPECT: single photon emission computed tomography

US: ultrasound

FDG: fluorodeoxyglucose

ROLL: radioguided occult lesion localization

RSL: radioguided seed localization

RGL: radioguided localization

SLN: sentinel lymph node

DOT: diffuse optical tomography

ACLY: ATP citrate lyase

ACACA: CoA carboxylase

PBA: aminopropyl-1-pyrenebutanamide

5βCA: aminopropyl-5β-cholanamide

ODA: octadecylamine

NMR: nuclear magnetic resonance

EDC: 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide

NHS: N-hydroxy succinimide

FBS: fetal bovine serum

DMF: N,N-dimethylformamide

RBF: round bottom flask

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HCl: hydrochloric acid

MeOH: methanol

EtOH: ethanol

DMSO: dimethylsulfoxide

MWCO: molecular weight cutoff

AOI: area of interest

SNR: signal to noise ratio

CNR: contrast to noise ratio

OCR: oxygen consumption rate

WSS: wall shear stress

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ABSTRACT

This work presents research using the natural carbohydrate glycosaminoglycan

hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of

nanoscale polymeric micelles loaded with either the near infrared (NIR)

fluorophore indocyanine green (ICG) for image guided surgery (IGS), or the fatty

acid synthase (FASN) inhibitor Orlistat (ORL) for chemotherapy. Hydrophobic

conjugates were synthesized and conjugated to HLA in order to drive self-

assembly into nanoparticles (NPs) and load their respective payloads. Chemical

composition was confirmed by mass spectrometry and NMR. NP self-assembly

was confirmed by dynamic light scattering (DLS) and atomic force microscopy.

Optical properties of ICG-loaded NPs, termed NanoICG, were examined and ICG

loading was found to be dependent on the structure of the hydrophobic ligand.

Fluorescence quenching was observed in aqueous solution, and fluorescence

could be reactivated by dissolution in a H2O:DMSO mixture, or in PBS with

bovine serum albumin (BSA). ICG release to BSA was observed in vitro. Nano-

ICG was found to have negligible cytotoxicity at physiologically relevant

concentrations. In vivo results in a xenograft mouse model demonstrated that

NanoICG provided superior contrast between tumor and surrounding muscle

tissue, and NanoICG successfully identified positive margins (PMs). ORL was

successfully loaded into NPs, termed Nano-ORL, at a loading efficiency of

approximately 98%. Hydrodynamic diameter was found to be dependent on ORL

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content. ORL extracted from Nano-ORL successfully inhibited FASN similarly to

free ORL, and Nano-ORL inhibited lipid synthesis in cells at approximately the

same level as free ORL. Nano-ORL was found to be more cytotoxic than free

ORL, and it was found that pre-incubation of both Nano-ORL and free ORL for 24

hours resulted in significantly reduced cytotoxicity of free ORL, while Nano-ORL

remained just as cytotoxic. Metabolic analysis showed that Nano-ORL has a

similar, negative impact on cellular metabolism as free ORL. These results

present novel contributions in the form of the comparison of hydrophobic ligand

structure in the loading of ICG into NPs, and the improved tumor accumulation

and contrast achieved in vivo. Additionally, these results present the first HLA-

derived NP formulation of ORL for use as a FASN inhibitor chemotherapeutic,

and show that Nano-ORL has equal or greater activity against cancer cell lines

than free ORL.

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CHAPTER 1

INTRODUCTION

1.0 Nanoparticles in Medicine and Biomedical Research

Research into the properties of nano-scale materials has seen a

significant advancement in recent years. These materials, despite differences in

molecular and atomic composition, scale, shape, and purpose, are broadly

grouped into the category of nanoparticles (NPs). NPs are generally considered

to be synthetic or biological constructs that exist in the size range of 1-1000 nm

in diameter.1 The term is often used to describe synthetic constructs but it is also

useful to describe small proteinaceous particles such as drug-bound albumin as

NPs.2 Of direct interest to human health are those NPs that are engineered to

provide some therapeutic or diagnostic effect for human disease. Material types

range from various polymers and lipids to silicone, metals, and fullerenes. Each

material type offers advantages as well as disadvantages and must be chosen

according to the specific application. The applications of NPs in health and

medicine broadly fall into either therapeutic or diagnostic categories, with a

hybrid branch commonly termed “theranostic” that aims to build NPs with both

diagnostic and therapeutic activity. The materials chosen for a specific NP

generally belie part of its function, such as liposomal and polymeric NPs being

used to solubilize drugs for therapeutic delivery, and superparamagnetic iron

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oxide NPs used for magnetic resonance imaging. Here we briefly review the

range of NP materials used in research and clinical application in order to better

grasp the full range of potential. We then focus on polymeric NPs, and NPs that

utilize the natural carbohydrate polymer hyaluronic acid (HLA) in particular. A set

of examples of NP types is shown in Figure 1-1.

Figure 1-1. Examples of NP types. (A) Liposomal NPs showing self-assembly

and drug loading into the aqueous core. (B) Gold NPs can be synthesized to

form various shapes by changing the growth conditions. (C) Quantum dots

typically have a polymer coating to solubilize them and prevent interaction with

proteins and cells. Polymeric NPs can be formed from block copolymers (D), or

polymeric chains with conjugated hydrophobic groups to drive self-assembly (E).

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Many HLA-derived NPs are of this type (E). (A, D&E) adapted with permission

from Macmillan Publishers Ltd: Davis, M. et al., Nanoparticle therapeutics: an

emerging treatment modality for cancer. Nature Reviews Drug Discovery 2008,

7(9). (B) adapted with permission from Mieszawska, A.J. et al., Multifunctional

Gold Nanoparticles for Diagnosis and Therapy of Disease. Molecular

Pharmaceutics 2013, 10. (C) adapted from Advanced Drug Delivery Reviews,

60(11), Smith, A.M. et al., Bioconjugated quantum dots for in vivo molecular and

cellular imaging, 1226-40, 2008.

Liposomal Nanoparticles

Liposomes may be composed of a number of different lipid combinations

and form at least one spherical lipid bilayer in solution. The structure of this type

of NP creates one or more hydrophobic zones in the form of bilayers, which

surround an aqueous region. Both the bilayers and aqueous regions may be

used to entrap drugs for controlled release and targeting.3 Liposomes were one

of the first NP formulations to be researched and extended to the clinic in the

form of Doxil®.1, 3 Doxorubicin (DOX) is an anthracyline with dose limiting

cardiotoxicity.4 Doxil®, first approved by the FDA in 1995, is a formulation of DOX

within a poly(ethylene glycol) (PEG) coated liposome.5 The combination of

liposomal entrapment and PEGylation allows Doxil® to be more effectively

delivered to tumors due to a decreased uptake by the reticuloendothelial system

(RES) in the liver, and has reduced cardiotoxicity compared to the non-liposomal

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formulation. A number of additional liposomal drug formulations have since

become approved or are under clinical investigation.3

Lipids, such as phosphatidylcholines and phosphatidylglycerols, are used

to form the lipid bilayers of liposomes. Cholesterol appears to make bilayers less

permeable to entrapped drugs, and may be added to decrease the rate of

release.6 Both PEGylated and non-PEGylated liposomes have been approved by

the FDA.3 Added to these formulations there may be additional moieties such as

protein ligands or monoclonal antibodies used to target certain cells or tissues.6

Attachment of additional molecules or atoms such as radionuclides for imaging

may also be done through addition of chelators or entrapment.6, 7

Currently approved liposomal formulations are available for a number of

indications.3 The largest group of approved liposomes, and the largest group of

new formulations in clinical trials, is directed toward chemotherapeutic delivery to

various solid or non-solid cancers. Additional formulations have been approved

for treatment of fungal infections, macular degeneration, influenza, meningitis,

pain, and hepatitis A.

Current clinical studies with liposomal drug carriers are primarily focused

on chemotherapy for cancer.3 In pre-clinical studies, research is focused on

combinations of active targeting, nucleic acid delivery, and multi-functional

formulations.6 In targeted delivery, the targeting ligand does not appear to cause

an increase in the total amount of NPs delivered to target tissues, though it may

have an effect on the uptake of those nanoparticles by target cells.6 Delivery of

nucleic acids has a great deal of potential in treating numerous human diseases,

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however the barriers remain equally significant. A number of investigations using

nucleic acid-bearing liposomes have been performed, but clearance, targeted

tissue delivery, and appropriate activity of delivered nucleic acids remain

significant issues in this field.6

Metallic Nanoparticles

A diversity of metallic NPs has been investigated in pre-clinical and clinical

studies. Of these, major groups include gold NPs (AuNPs) and iron oxide NPs.

Both of these materials allow for extensive modification through physical or

chemical attachment of coatings, targeting moieties, or drugs, which improve

circulation time, delivery, and treatment. Additionally, both gold and iron oxide

NPs have proven useful as contrast agents for various imaging modalities, giving

these materials an incredibly diverse potential for use in medicine.

AuNPs have been investigated extensively for multiple diagnostic and

therapeutic methods.8-10 The breadth of potential of AuNPs results from a

number of useful properties, including easy synthesis, modification, and both

diagnostic and therapeutic potential. AuNPs can be synthesized easily in the lab

and control of shape makes it possible to produce spheres, cubes, rods, stars,

and plates. While gold is largely physiologically inert, thiols can be easily

conjugated to gold surfaces for improved functionality and biocompatibility.

PEGylation is a common method,11-13 but addition of proteins or other polymers is

also used.9, 14 AuNPs have been used for X-ray contrast agents, fluorescence

imaging, surface enhanced Raman spectroscopy, delivery of drugs and nucleic

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acids, and photothermal therapy.9 The density of AuNPs makes them well suited

for X-ray imaging, and combination with Gadolinium allows for multimodality

CT/MRI.15 Combination drug and photothermal therapy using AuNPs was

investigated by Park et al., who found a synergistic effect between photothermal

therapy and delivery of DOX.16 Not only was DOX release improved when

AuNPs were treated with near infrared (NIR) light, but the total cytotoxic effect

was significantly more pronounced when both photothermal therapy and DOX

were present than when only one or the other were used. Fluorescence of

AuNPs allows for combined imaging and therapy by combining the fluorescence

imaging with photothermal ablation of tumors.17-19 Jang et al. combined

fluorescent AuNPs with photosensitizers for combined imaging, photodynamic

therapy, and photothermal therapy. Fluorescent imaging of tumors gave a

maximum tumor-to-background ratio of only 3-4, but the combined treatment of

photodynamic therapy to produce reactive oxygen species and photothermal

therapy for thermal ablation resulted in significantly smaller tumors than groups

receiving other treatments eight days after treatment. Given the ease of use and

these encouraging results it seems likely that AuNPs will find their way to human

treatment.

Magnetic NPs are generally composed of various forms and alloys of iron.

Magnetite (Fe3O4) and maghemite (Fe2O3) NPs, as well as alloys with Mn, Co, or

Ni have been investigated for MRI signal enhancement, drug delivery, and

hyperthermia.20 Superparamagnetic iron oxide (SPIO) NPs have received much

of this investigation due to the low toxicity and surface that can be modified for

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biocompatibility, targeting, and therapy.21 A number of these have been clinically

approved, including GastroMARK® (ferumoxsil), Combidex® and Feridex IV®.21

Those SPIOs that have been approved have been used as MRI contrast agents.

The usefulness of SPIO NPs lies in their ability to be magnetized but possess no

net magnetization, which allows them to retain colloidal stability.20 This allows for

injection and target tissue accumulation, which can then be imaged with MR with

either T1 or T2 weighting. Several polymer coatings have been investigated to

improved pharmacokinetics of SPIO NPs in vivo. Commonly used among NPs is

PEG, which reduces recognition by the RES and thereby increases circulation

time. Dextran and chitosan polysaccharides have also been used as hydrophilic,

biocompatible, and biodegradable coatings for SPIO NPs.21 SPIO NPs may also

be targeted to specific tissues and cells by addition of targeting moieties such as

antibodies, proteins, and small organic molecules such as folate.21-24 A number

of strategies have also been investigated for chemotherapeutic delivery with

magnetic NPs, which has primarily focused on cancer therapy. Investigated

drugs include paclitaxel, DOX, and methotrexate, and strategies involve physical

complexation, entrapment within a hydrophobic coating, or attaching cleavable

linkers for specific release upon delivery to target tissues.21 Magnetic NPs may

also be used as part of a larger NP complex. Ito et al. embedded magnetite NPs

within liposomes, which were targeted with anti-HER2 antibodies, allowing for

combination antibody and hyperthermic treatment.25

Quantum Dots

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Quantum dots (QDs) are nanoscale particles made from semiconducting

materials such as cadmium sulfide, cadmium selenide, or cadmium telluride,

which have size-dependent fluorescence that can be tailored to wavelengths in

the NIR. Due to their high quantum yields and small size QDs have been

investigated for their potential in both in vitro and in vivo imaging.26, 27 However,

the synthesis processes and materials required necessitate further solubilization

and improvements in biocompatibility, such as conjugation of PEG or loading into

liposomes or polymeric NPs. Nonetheless, QDs have shown pre-clinical

successes in imaging cellular processes and lymph nodes. Jaiswal et al. used

endocytic uptake and surface labeling with antibodies to specifically label cells for

imaging over the course of a full week.28 Kim et al. showed that NIR fluorescent

QDs coated with oligomeric phosphine resulted in soluble NPs approximately 10

nm in diameter,29 which were capable of tracking the lymphatic system in both

healthy mice and pigs, indicating the potential for QD tracking of sentinel lymph

nodes (SLNs) in cancer patients. Further work is needed to prevent toxic side

effects of QDs, as the materials that compose QD cores may contain relatively

large amounts of Cd, Te, Pb, or As.

Polymeric Nanoparticles

An enormous variety of polymeric materials have been investigated as

materials in NPs for use in medicine and cancer in particular. Combinations of

random and block co-polymers utilizing poly(glutamic acid), poly(lactide),

poly(caprolactone), N-(2-hydroxypropyl)methacrylamide, numerous hydrogel

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materials, and polysaccharides such as chitosan, dextran, and HLA have all

shown potential as materials for drug delivery or imaging.30-35 Some of these

drugs have found and are finding their way into the clinic, such as Cremophor-

paclitaxel, a micellar formulation of castor oil and PEG, and next generation

drugs such as Genexol®-PM, a polymeric micelle formulation composed of

diblock co-polymers of PEG-poly(D,L-lactic acid) and paclitaxel.36-38

The advantages of polymeric NP formulations results from several

attributes.1, 20, 34, 39-41 First, the wide variety of polymers and molecular weights to

choose from allows for a high degree of control over the properties of the NPs.

The ability to synthesize random or block co-polymers, dendrimers, polymer-

conjugates, and composite materials allows for synthesis of a huge variety of

NPs. Many of the NP types previously discussed such as liposomal and metallic

NPs have been investigated as composite materials utilizing one or more

polymers. Polymeric NPs are capable of loading a variety of drugs, contrast

agents, and nucleic acids, both non-covalently and covalently. This can improve

solubility and lessen dose-limiting toxicity. Surface modification with ligands and

antibodies may improve targetability, and many polymers are biodegradable and

biocompatible, allowing for higher levels of exposure without associated toxicity.

Of particular interest to this work are polymeric nanoparticles containing

hyaluronic acid, a naturally occurring biopolymer with a wide range of

physiological functions.

Hyaluronic Acid Derived Nanoparticles

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Hyaluronic acid (HLA), or hyaluronan, is a linear, anionic polysaccharide

composed of β(1,4) D-glucuronic acid β(1,3) N-acetyl-D-glucosamine (Figure

1.2). HLA is present ubiquitously throughout the human body, primarily in the

ECM of soft tissues, and acts to lubricate joints and to support connective

tissue.42 High levels (> 200 µg/ml) of HLA are found in the umbilical cord,

synovial fluid, and dermis.43, 44 HLA is very hydrophilic as it contains a relatively

large number of hydrogen bond donors (5) and acceptors (12) compared to the

number of carbons (14) per repeat unit. This primary structure causes HLA to

retain water very well, which contributes to its function in the ECM.45 The

presence of the carboxylic acid on D-glucuronic acid further contributes to its

usefulness in material applications as this moiety may be used for crosslinking

and conjugation.

Figure 1-2. Hyaluronic acid is a polymer of repeating β(1,4) D-glucuronic acid

(left) and β(1,3) N-acetyl-D-glucosamine (right). The natural MW of these

polymers are in the range of 105 – 107 Da and can be tens of microns in length.

Degradation by acid catalyzed hydrolysis or using hyaluronidases can occur to

further reduce the MW.

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In addition to these roles, HLA serves as the ligand for several receptors

including CD44 and RHAMM. In cancer HLA has been found at high levels in

multiple tumors types, including breast, ovarian, non-small cell lung

adenocarcinomas, and prostate cancer, and high levels have been associated

with increased invasiveness.42 Additionally, some tumors also express high

levels of hyaluronidases HYAL-1 and HYAL-2, a case that may be involved in

increased malignancy.42, 46, 47 CD44 and RHAMM signal transduction are likely

pathways that link HLA to tumor behavior, and CD44 splice variants have been

associated with more malignant cancers.48

HLA has been used previously for NP formulations and NP delivery to

tumors. Because of its hydrophilic nature, HLA must be conjugated with other

materials to form discrete NPs. Choi et al. showed that conjugation of HLA with a

5β-cholanic acid moiety triggers self-assembly of ≈200 kDa MW HLA into NPs,

and that these NPs accumulate in tumors to a higher degree than non-

conjugated HLA polymers.49 This work was continued by introducing PEGylation

of NPs, which resulted in improved delivery to tumors by avoidance of RES

uptake, and further continued by loading of the hydrophobic chemotherapeutic

drugs DOX and camptothecin into these PEGylated NPs.50, 51 In vivo delivery of

camptothecin using these NPs showed a reduction in tumor growth over the

course of 35 days when compared to free camptothecin, suggesting improved

delivery to tumors. More recently, these materials have been used as nucleic

acid delivery systems for RNA interference and have shown preclinical success

in gene silencing.52 Additional studies have investigated the potential for inclusion

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of photosensitizers for photodynamic therapy.53 Yoon et al. utilized the loading of

chlorin e6 within PEGylated HLA NP cores, which was delivered to tumors in vivo

and showed improved tumor size reduction after treatment with NIR light

compared to delivery of free chlorin e6. Zhang et al. loaded Cy5.5 conjugated

HLA NPs with CuS for combined photoacoustic imaging and photothermal

therapy.54 Both studies delivered these NPs in vivo and found that treatment

reduced tumor volumes compared to controls. Similar studies have used

additional hydrophobic ligands such as the amino acid histidine.55

Other studies have examined HLA composites and co-polymers in the

formation of NPs. Studies by Cho et al. examined NPs formed by first

conjugating ceramide to HLA, followed by mixing with Pluronic p85 in an attempt

to improve NP stability and overcome multidrug resistance, and showed cellular

toxicity and uptake within tumors.56 Further work utilized PEGylation of HLA-

ceramide NPs loaded with DOX, which resulted in smaller tumor volumes than

non-PEGylated NPs loaded with DOX, presumably due to increased circulation

time and lower uptake by the RES.57 Co-polymers of HLA have also been

examined using chitosan or poly(D,L-lactide-co-glycolide) for gene delivery and

drug delivery respectively.58, 59 Composite NPs of gold-HLA and SPIO-HLA have

also been investigated. Dakdouki et al. utilized HLA coated SPIO NPs to improve

uptake into cancer cells, which allowed for MR imaging as well as drug delivery

by conjugation of DOX.60 These NPs resulted in a greater decrease in T2*

compared to Feridex, a clinically approved SPIO NP, and greater cytotoxicity at

equivalent concentrations to free DOX. Another study utilized direct conjugation

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of HLA to AuNPs in addition to the antibody drug Tocilizumab for the treatment of

rheumatoid arthritis.61 These NPs resulted in greater reduction (improved

treatment) of mean clinical scores for arthritis induced in mouse feet compared to

either AuNPs without Tocilizumab, or free Tocilizumab, indicating that HLA was a

determining factor in treatment improvement.

In cancer imaging, HLA has been investigated preclinically for SLN

mapping and image guided surgery. While not utilized in NP formation, HLA was

mixed with patent blue or SPIO NPs and injected into the gastrointestinal tract of

pigs, which resulted in prolonged and more discrete staining of lymph nodes.62

However, this resulted primarily from the increased viscosity of the HLA-dye

solution rather than NP-mediated delivery. HLA-indocyanine green conjugates

have been examined for use in image guided surgery by direct conjugation of

ICG-OSU, a derivative of indocyanine green (ICG) that can be conjugated

directly to HLA. This formulation successfully accumulated in xenograft tumors

after systemic injection, however, while ICG is an FDA approved fluorophore,

ICG-OSU is not.

The extensive application of HLA, either as hydrophilic backbone, co-

polymer component, surface coating, and conjugate in NP formulations clearly

demonstrates its versatility. HLA is hydrophilic, biodegradable, biocompatible,

and possesses numerous sites for simple conjugation. It also has potential to

serve an active targeting function either through CD44 targeting or degradation

by hyaluronidases expressed within tumors. A summary of the NP formulations

utilizing HLA is found in Table 1-1.

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Use of HLA NP type Indication Action Reference

Backbone Polymeric micelle (5β-cholanic acid conjugate)

Solid tumor

Pre-Drug delivery 49, 50, 63

Drug delivery 51

siRNA/miRNA delivery 52

Phyotodynamic therapy/imaging

53, 54

Polymeric micelle (Histidine conjugate)

Drug delivery 55

Polymeric micelle (Ceramide conjugate)

Drug delivery 56, 57, 64, 65

Photo X-linked HLA Drug delivery 66

Chemically X-linked HLA

Drug delivery 67

Polymeric micelle (Flt-1 conjugate)

Asthma Dexamethasone delivery

68

Co-polymer Polymeric micelle Poly(DL-lactide-co-glycolide)

Solid tumor Drug delivery 58, 69

Polymeric micelle Poly(ethyleneimine)

siRNA delivery 70

HLA-chitosan Various Nucleic acid delivery 59, 71-73

Asthma Heparin delivery 74

Table 1-1. Summary of recent literature utilizing HLA in NP formulations.

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Use of HLA NP type Indication Action Reference

Surface Moiety

SPION Solid tumor MRI, drug delivery 60

Macrophages Imaging 75

AuNP Rheumatoid arthritis

Immunotherapy 61

Hepatitis C Interferon α delivery 76

Diagnostics Nanoprobe 77

Mesoporous silica within liposome

Solid tumor Drug delivery 78

Lipid NP cluster Solid tumor Drug delivery 79, 80

Calcium phosphate NP Solid tumor siRNA delivery 81

Table 1-1. (continued)

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2.0 Biodistribution and Toxicity of Nanoparticles

NP formulations are advantageous due to their size and chemical

characteristics. The volume of NPs ranging from 10-500 nm in diameter is large

enough to provide both interior hydrophobic environments in which drugs and

small molecules can be loaded, while retaining a hydrophilic exterior to allow for

solubility in blood. Additionally, the high surface area to volume ratio allows for

chemical modifications that actively target specific cells and tissues, or provide

immuno/metabolic evasion.82, 83 Perhaps most importantly, NP diameters can

often be tailored to fall within the critical size range to take advantage of the

enhanced permeability and retention (EPR) effect displayed by many tumor

types. Nonetheless, efficient delivery to target tumors remains difficult, with only

a small percentage of injected dose being delivered. The barriers to effective

delivery of NPs are numerous.84 The size range must be greater than

approximately 6 nm to avoid renal filtration, but sufficiently small to allow for

extravasation into the tumor stroma.85 Off-target delivery, particularly uptake by

the RES, results in the majority of NP loss. For those particles that do

extravasate into the tumor, they must then diffuse through the tumor stroma,

avoid diffusion back into circulation or lymphatic drainage, and be taken up by

target cells, should uptake be necessary for their function. For NPs that do not

find their destination, the toxicity from off-target delivery or accumulation

represents a significant concern, particularly for drug delivery formulations that

require continued dosing for efficacy. These difficulties have been met by

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research into the effects of surface modification, charge, size, shape, material

composition, and conjugation of targeting and stealth ligands.

The Reticuloendothelial System (RES)

The RES is a system of macrophages found in the liver, spleen, and bone

marrow that is capable of selectively removing particles from the blood which

have bound opsonin proteins.84 RES clearance is most prominent in the liver and

spleen, and does not result from specific recognition of NPs by the macrophages,

but rather from serum proteins bound to the NPs. These proteins are called

opsonins and primarily include complement proteins and antibodies.86 Opsonin

binding can result in rapid clearance of NPs from the body and thus drastically

reduce circulation and delivery. Thus, reduction of RES uptake is a key attribute

of good NP formulations. However, even for NP formulations that guard against

recognition by use of stealth mechanisms such as PEGylation, RES uptake

remains significant, often at more than 50% of injected dose.84

Tumor Structure and the Enhanced Permeability and Retention (EPR) Effect

For those NPs that are not taken up by macrophages, penetration into the

tumor and delivery to cells provides an additional barrier. Tumor biology is

complex and varies between tumor types, location, and patients. For these

reasons, the vascular and stromal structures of any one tumor will be unique,

and will thus result in different NP distributions. The extent of NP penetration into

and retention within tumors depends on the vascular fenestration size, density

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and composition of the ECM, pressure, and lymphatic drainage. These features

are likely to be so variable that different NP formulations may be required for

different tumor types. Nonetheless, similarities exist between all tumors exhibiting

enhanced permeability and retention.

The EPR effect results from the poor vascular formation in solid tumors,

causing preferential retention of macromolecules and NPs in solid tumors.82, 87-90

When tumors reach a sufficient size, approximately 2-3 mm in diameter, oxygen

and nutrients cannot diffuse rapidly enough to support cells in the interior of the

tumor. When this occurs, growth factors are released that trigger angiogenesis in

the surrounding tissue, forming new blood vessels. The vasculature formed

however, is not well structured. Endothelial cell linings are generally not as close

as in healthy vasculature and there is often a poorly formed or complete lack of

smooth muscle cells lining the basement membrane. These properties lead to

the increased extravasation of all molecules that can fit between the

fenestrations in the endothelial layer, ranging from 200-2000 nm. After

extravasation, larger particles are preferentially retained in the tumor due to the

lack of appropriate lymphatic drainage. While ions and small molecules can

diffuse back into the vasculature, macromolecules and NPs do not diffuse back

as rapidly and thus tend to accumulate within the tumor interstitium. Thus, NPs

with diameters smaller than the fenestrations can passively target those tumors

without additional motivating forces. However, due to variability in the structure

and extent of vasculature, tumor stroma, and lymphatic drainage, the EPR effect

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varies by tumor type and location, making it a useful but not ubiquitous targeting

method.

The Mechanical Environment

A theme that is frequently absent from the discussion in NP delivery is the

physical environment experienced by NPs in flow conditions. Wall shear stress

(WSS) is the tangential force applied to a surface by a fluid moving across it. At a

molecular level, WSS is essentially a measure of lateral contact forces between

molecules moving at different velocities. In an ideal cylinder, shear stress is

highest at the solid-liquid interface (WSS), and decreases toward the center of

the cylinder. Physiological WSS values range from 50 dyne/cm2 in the aorta,91

2.8-100 dyne/cm2 in capillaries,92 and 17-211 dyne/cm2 in arterioles.93 In mice

aortas, WSS values are predicted to range from 60-220 dyne/cm2, and can be as

high as 600 dyne/cm2.94 For comparison, water flowing at 1 ml/s in a 3.175 mm

(1/8”) diameter tube experiences WSS of around 2.5 dyne/cm2, and solutions

standing stationary experience essentially zero shear stress. Contact between

NPs and vascular walls, as well as collisions with serum proteins, cells, and other

molecules can thus be significantly higher than what is normally experienced in

laboratory practice.

Nanoparticle Properties Affecting Delivery

Every aspect of the NP affects the interaction its biological environment,

which includes cells, ECM and serum proteins, and physical factors such as flow

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and fenestration size. NP size has physical effects on renal clearance,

extravasation, diffusivity, and influences cellular interaction. NP shape also

influences cellular interaction and cellular uptake by both cancer and

macrophage cells. Surface charge, either positive or negative, may lead to

interaction with charged groups in the extracellular matrix, while surface polarity

may influence solubility and protein binding. Some of these effects may be

hidden by surface modification. As concerns net biodistribution, the benefit of

adding active targeting ligands has shown mixed results, but appears to produce

increased cellular internalization, which may improve efficacy. These issues

result in an incredibly complex set of parameters that must be considered when

designing new NP formulations for a given purpose.

Size

Nanomaterials are by definition on the order of nanometers in at least one

dimension, and in the case of NPs, three dimensions. These scales are chosen

due to the unique physical and chemical properties that arise from particles at

this scale, one of which is delivery and accumulation within tumors. However,

even the effect of size on NP delivery is multifaceted. NPs above 6 nm but

smaller than the 200-2000 nm vascular fenestration size of tumors will avoid

renal clearance and penetrate into the tumor stroma to some extent.82 However,

a further hindrance to delivery is the 50-100 nm fenestrations in the liver and

interaction with hepatocytes that results in RES uptake.84 And what is optimal for

avoiding RES uptake may not be optimal for tumor uptake. Cabral et al. found

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that 30 nm drug loaded polymeric micelles, with a size small enough to pass

through liver fenestrations, had the best penetration into poorly permeable

tumors, compared to 50, 70, and 100 nm micelles, though all sizes penetrated

well into highly permeable tumors.95 Complicating the matter more, what is

optimal for tumor uptake may not be optimal for tumor retention. Torchilin et al.

showed that small 10 nm micelles accumulated in the tumor within 30 minutes of

administration, but the total dose of taxol within the tumor was substantially lower

at 2 hours compared to 30 minutes, unless a tumor targeting antibody was

present.96 While this observation possibly indicates a retention effect due to

targeting, it is complicated by the addition of large (>100 kDa) monoclonal

antibodies to an already small micelle, making it difficult to separate the effects of

active targeting and decreased diffusion out of the tumor. Other work was

performed strictly examining the MW on the effect of tumor penetration and

retention. Dreher found that increasing the MW of fluorophore-linked dextran

from 3.3 kDa to 2 MDa resulted in significant and meaningfully lower vascular

permeability, a 100-fold reduction overall for the 2 MDa construct.97 However,

total tumor accumulation was highest for 40-70 kDa molecules, as higher MWs

resulted in lower penetration but longer circulation time, while lower MW resulted

in higher penetration but rapid diffusion back into circulation. Another study found

a size dependency of AuNP size in relation to uptake by HeLa cells, with 50 nm

AuNPs being taken up to a higher extent than 14, 30, 74, or 100 nm NPs.98

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Shape

NP shape also influences biodistribution. Champion and Mitragotri found

that differently shaped polystyrene particles had different rates of phagocytosis.99

These “worms”, elongated polystyrene particles, were multiple micrometers in

length and had volumes equivalent to 3 µm diameter spheres. It was observed

that the worms had significantly lower uptake by macrophages than spheres of

equivalent volume. However, these worms had lengths of approximately the

same size as the macrophages and thus may not represent the behavior of

macrophages interacting with nanoscale materials. Chauhan et al. examined the

effect of shape with nanoscale materials using PEGylated 35 nm diameter

CdSe/CdS quantum dot core with silica shell spheres, and PEGylated 54 nm

length CdSe quantum dot core, CdS elongated rods.100 The results showed that

the transvascular flux and intratumor distribution of the rods were both

significantly higher than the spheres. However, the mass difference of these

particles was not given, and a volumetric calculation shows a much higher

volume of the spheres than the rods, which may be a contributing factor to the

differences observed. Chithrani also found a shape dependency on cellular

uptake by HeLa cells, with lower aspect ratio AuNPs being taken up more than

high aspect ratio AuNPs.98 However, this effect could be two-sided, as increased

uptake could benefit intracellular delivery of drugs, but hinder delivery by

increasing uptake by macrophages.

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Charge

NP charge has a significant effect on uptake by the RES as well as

penetration through the tumor stroma. It is generally agreed that NPs with a

moderate zeta potential (ξ) between ±10 mV have lower uptake by the RES.84, 101

Levchenko found that the rate of liposome clearance was dependent on ξ, with

more highly charged liposomes being cleared more rapidly.102 Similar results

have been produced in other studies utilizing different materials, suggesting that

this effect does result from differences in ξ.103, 104 This effect of surface charge

likely results from alterations in NP interaction with plasma proteins, cell surface

proteins, and the stroma. The presence of high surface charge on NPs increases

opsonization and thus uptake by the RES.86 However, while net charge leads to

uptake, the surface must also be sufficiently polar, as uncharged but hydrophobic

surfaces also result in higher levels of opsonization.105 Charge effects interaction

with both serum and stromal proteins, and thus also influences the penetration of

NPs into tumors and other tissues. With regard to stromal proteins, again we

observe that particles with close to neutral ξ result in higher tumor penetration.82,

84 These results have been explained theoretically by modeling NP interactions

with extracellular matrix molecules such as collagen and HLA.106 The model

agreed that particles with higher surface charge density should experience lower

diffusion into the stroma due to interactions naturally occurring between positively

and negatively charged molecules, and thus near neutral surface charge is ideal

for tumor penetration after extravasation. This trend is confirmed by the effect of

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surface modification of NPs, particularly the use of PEG, which provides a

surface barrier of uncharged hydrophilic polymers.

Surface Modification

In order to combat the effects of opsonization or non-specific interaction

with stromal proteins, and potentially allow for targeted delivery, a number of

strategies for conjugation of surface moieties have been developed. Perhaps the

most common methodology for making “stealth” NPs is PEGylation.86 PEGylation

works because PEG is uncharged, non-specific, and has low protein association.

This provides a physical buffer that reduces protein interaction with the

underlying material, which reduces binding of opsonins, decreases uptake by

immune cells, and lowers interaction with the extracellular matrix. However, the

strategy of PEGylation is not without issues. Treatment with PEGylated NPs may

result in development of hypersensitivity to PEG, resulting in decreased efficacy

of future treatments. Judge et al. found that treatment of mice with PEGylated

plasmid-containing liposomes resulted in the production of an anti-PEG antibody

that decreased delivery to tumors after repeated exposure.107 In addition to

adaptive immune response, PEG may also trigger a response of the innate

immune system through complement activation. A study in humans using Doxil®

(PEGylated liposomal DOX), found hypersensitivity reactions and complement

activation following administration in 45% of patients.108 However, it is not clear

from this study what component of Doxil triggered the response. The quantity

and molecular weight of PEG also influences biodistribution. In micellar and

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liposomal formulations, the total quantity of PEG may also affect the stability of

the NPs themselves.109 It has been reported that adding a sheddable layer of

PEG could provide the benefits of increased circulation time while allowing for

reduced toxicity and sensitivity.109 Additional methods of making stealth NPs

have been investigated as well, including alternative polymers110 or conjugation

of “self” peptides that cause immune recognition of NPs as belonging to the host.

Active targeting refers to the strategy of linking proteins, peptides,

antibodies, or any molecule that is specific to some aspect of tumor biology in

order to improve tumor or cancer cell uptake. While active targeting does not

appear to influence the physical factors determining NP deposition within tumors,

evidence is building that it does affect receptor mediated endocytosis and thus

may serve as a complementary strategy in tumor accumulation.82 The large

number of FDA approved immunoconjugated drugs and imaging agents

suggests that there is indeed a basis for active targeting with NPs.111 However,

studies have suggested that the net effect on tumor accumulation may be small,

and the improved efficacy of targeted NPs results from increased cellular

internalization.112, 113 It must also be realized that the addition of active targeting

moieties to the surface of NPs may alter the biodistribution of these NPs, further

complicating the issue. Nonetheless, a number of targeted NP formulations are

currently in clinical trials, the majority of which are targeted to solid tumors, and a

large number of preclinical studies have taken place.114

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Toxicity

The study of NP toxicity is a complex issue, due in large part to the vast

array of materials and associated drugs and other molecules that compose NP

formulations. Currently however, NPs approved for biomedical use have a good

record in this area, particularly those formulations designed to deliver

chemotherapeutics. Doxil provides one of the best examples, as the liposomal

formulation of DOX prevents diffusion across healthy endothelial barriers and

thereby greatly reduces the cardiotoxicity observed with free DOX.115 However,

the toxicity profile of each new NP formulation will need to be determined

independently. Broadly, the concerns in NP toxicity are the generation of reactive

oxygen species (ROS), size and shape dependent accumulation, and material

chemistry.116, 117 Generation of ROS has been observed across multiple NP

types. Damage occurs from oxidative stress through reactions with critical

cellular components such as DNA and the cell membrane. Accumulation due to

NP size and shape may occur in a number of locations, including the liver,

spleen, pulmonary system, and macrophages.116 This may itself result in a range

of complications, including inflammation, direct interaction and disruption of

protein and nucleic acid function, and further generation of ROS. Direct material

toxicities have been reported through environmental studies of metal oxide NPs,

but this may depend on the both the route of administration and the total dose.118

Unfortunately, there may also be poor overlap between in vitro and in vivo

toxicological assays. Attempts to improve overlap have utilized 3D cell culture

and cell co-culture techniques, but because of the vastly different dynamics

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experienced by NPs in vivo and the much larger array of cell types and cell

interactions, this overlap will likely never be entirely complete.116, 117 Careful

analysis will be required for each new NP formulation, as differences in

physicochemical properties of the materials will result in different biodistributions

as previously discussed, and subsequent cellular, tissue, and organ interaction

will depend on NP material reactivity, biodegradability, and therapeutic payload.

3.0 Clinical Imaging in Oncology

Clinical cancer imaging utilizes a number of different modalities, including

computed tomography (CT), magnetic resonance imaging (MRI), positron

emission tomography (PET), single photon emission computed tomography

(SPECT), ultrasound (US), and optical imaging. While this may appear to

provide a number of viable options for imaging of various cancers, in themselves

all of these modalities lack specific targeting of neoplastic tissue. Molecular

probes, such as fluorodeoxyglucose (18F) (FDG), are capable of specifically

targeting cancer cells, and molecular targeting is available clinically for use with

PET, SPECT, and MRI.119 Molecular targeting with x-ray (CT) imaging is unlikely

to occur due to the high molar quantities required to attentuate x-rays.120 The use

of microbubbles as contrast agents in US remains outside the realm of

oncological imaging as the size of the these bubbles prevents their extravasation

into the tumor stroma.120 Targeted optical imaging however has been used both

pre-clinically and clinically, and though the techniques, materials, and

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instrumentation are still either new or experimental, this methodology holds

significant potential, particularly in the field of image guided surgery.121, 122 Here

we review the basic medical imaging modalities and their uses in cancer

diagnosis and treatment, with a focus on the potential for intraoperative image

guidance.

X-ray and Computed Tomography

X-rays are produced by the acceleration of electrons through a potential

difference to a target anode where a small percentage of them come close

enough to target nuclei that the electrons lose kinetic energy and subsequently

release an x-ray photon.123 These photons are then either scattered or absorbed

by molecules in tissue, causing attenuation depending on tissue density and

composition. X-ray photons that are not absorbed by the tissue then reach either

a screen-film or charge coupled device that records their location, providing

information on electron flux through the tissue of interest.

Perhaps one of the most pervasive and common medical imaging

procedures is the mammogram. This technique utilizes x-rays to detect

neoplasms in the breasts and has become a standard of care in screening over

the last several decades. Mammography has clearly proven successful in

reducing the number of late stage diagnoses and deaths from breast cancer,

however specific contrast agents are not available for standard mammographies

and recent analyses of long term clinical utilization of mammography screening

have shown that overdiagnosis is common.124, 125 Bleyer et al. have estimated

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that approximately 70,000 women were overdiagnosed with breast cancer in

2008, approximately one-third of all breast cancer cases. This overdiagnosis

undoubtedly results in unnecessary medical expenditures, procedures, and

patient duress. Thus, new methods of breast cancer screening are underway,

including those utilizing dedicated CT.126 Breast cancer screening with CT may

improve resolution and thus potentially serve to both decrease incidence and

overdiagnosis, but additional work is needed to determine the degree of

improvement over standard mammography.126, 127

Virtual colonoscopy by CT imaging remains a potential screening route to

replace traditional colonoscopy. Traditional colonoscopy is an effective procedure

but remains highly invasive. Earlier studies showed that virtual colonoscopy may

not provide sufficient sensitivities for detection of cancers128, however recent

studies have suggested that the sensitivities are adequate for detection of

colorectal cancer and may even exceed that of optical colonoscopies when

appropriate techniques such as fecal tagging are used.129

Clinical CT provides anatomic imaging, and can easily distinguish

between soft and hard tissues such as bone and surrounding muscle. CT also

has comparatively good resolution (~1 mm3) compared to nuclear imaging

modalities, which have resolutions of approximately 8-12 mm3.120 However, CT

contrast agents must be injected at molar quantities and quickly become diluted,

thereby precluding targeted imaging.120 CT therefore lacks functional imaging

that can be found with nuclear imaging modalities such as PET and SPECT.

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Thus, dual modality imaging has become a subject of intense research and

clinical application in oncology.

PET and SPECT

PET and SPECT operate by detection of gamma rays emitted from

radionuclides delivered to the tissue of interest. In the case of PET, the

radionuclide first releases a positron, which then collides with a nearby electron

to release two oppositely directed gamma rays.130 PET is well known for its use

of FDG, a glucose analog that is taken up by cancer cells exhibiting high levels of

aerobic glycolysis.131 Additional functional imaging agents are also in use

clinically for both PET and SPECT.119, 132 The advantage of PET lies in the ability

to synthesize radiolabelled probes that mimic molecules used in cells’ molecular

machinary, thereby allowing for imaging of functional aspects of cancers.

Additional tracers in use include analogues of thymidine, choline, methionine,

tyrosine, and several others.133 This versatility of PET allows for its use in both

pre and post-treatment of cancers, through diagnosis, staging, and restaging.

Combined imaging modalities are extremely powerful in their ability to

distinguish both anatomic and functional aspects of tissues. The combination of

PET/CT allows for high resolution anatomic imaging with combined functional

molecular imaging analysis, allowing for differentiation of healthy and diseased

tissue by physical and biochemical attributes.134 Combined PET/CT scanners are

preferable for this methodology in order to avoid discrepancies in the physical

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position of organs and patient. Similar attributes are available with SPECT/CT

systems.135

Combined imaging with PET/MRI may also be done to image cancers for

multiple aspects of molecular and physical properties. For example, PET imaging

can acquire data regarding expression of cell surface proteins and changes in

those levels during treatment, while MRI can acquire physical data such as cell

density and perfusion.136 Thus, combined PET/MRI imaging can acquire data on

biochemical and physical characteristics of tumors for diagnosis, staging, and

progression during treatment that is not available through other modalities.136

Magnetic Resonance Imaging

MRI is regarded as the most useful imaging modality for imaging of soft

tissue, with resolution at approximatley 1 mm3 being comparable to CT and

US.120, 132, 136 This imaging modality relies on the alignment of the magnetic spin

of nuclei in a strong magnetic field and subsequent perturbations of the spin axis

by a secondary magnetic field. Protons of nuclei in different physical

environments will return to their original alignment at different rates, thus allowing

tissue contrast and imaging. The ability to precisely image soft tissues at high

resolution at any depth makes MRI particularly useful for cancer imaging, and

this modality is not limited to simple anatomical imaging. MRI can also be used to

perform functional imaging using perfusion, diffusion, and contrast agents such

as ferumoxide, ferumoxtran, and ferumoxytol, all of which are iron oxide

particles.119 Gadolinium ions, which are paramagnetic and shorten T1 relaxation

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times of nearby protons, are also a commonly used MRI contrast agents.137, 138 A

number of studies show the effectiveness of MRI imaging in breast and prostate

cancer. MR imaging in breast cancer was estimated to diagnose an additional

16% of patients with a positive predictive value between 52 – 77%, indicating

approximately twice as many true positives as false positives.139 However,

screening and staging with MRI has also been shown to result in changes to

decision making regarding surgical care, tending towards more radical surgeries,

and the improvement in patient outcomes may not be improved.139, 140

Multiparametric MRI has also shown to be useful in imaging of prostate

cancer.141-143 Prostate cancer is typically diagnosed through non-imaging means

such as detection of prostate specific antigen and biopsy, however the potential

for anatomical and functional MR imaging has the potential to supplement these

methods by biopsy guidance and preoperative characterization, and detection of

local recurrance. The introduction of targeted contrast agents may further the

potential for diagnosis and screening as well.136

Non-fluorescence Optical Imaging

Imaging with visible light remains one of the most widely utilized forms of

imaging in medicine. Endoscopy of the upper and lower gastrointestinal tract,

and laparoscopic surgery, are the the major fields where optical imaging

technology is utilized. Upper GI tract endoscopy has proven successful in the

identification of numerous cancers, including esophageal and gastric cancer.144

Similarly, the small intestines and lower GI tract can also be imaged

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endoscopically, either through placement of handheld instrumentation or by

swallowing a small capsule that images the gut during its passage.145

Related to optical imaging are other imaging methodologies that utilize

visible or NIR light to diagnose cancer. Optical coherence tomography,

photoacoustic imaging, and raman spectroscopy are less widely used or remain

under investigation for oncologic imaging, but may play a role in the future.

Optical coherence tomography, which utilizes near infrared (NIR) light reflections

from tissue, is currently being investigated for imaging of both cervical and

bladder cancers.146 Photoacoustic imaging utilizes heating of tissue by photo-

irradiation, which results in thermal expansion and the production of a

mechanical wave that can then be measured by ultrasound.147, 148 Raman

spectroscopy is also under investigation for diagnosis of breast cancer, and has

proven successful in identifying cancer in tissue samples, though not yet in

patients.149, 150

Non-fluorescence Intraoperative Tumor Detection

Radiological techniques are also used in the intraoperative treatment of

cancer. Radioguided occult lesion localization (ROLL), and radioguided seed

localization (RSL), together termed radioguided localization (RGL) for the

intraoperative identification of non-palpable breast cancer.151, 152 These

techniques utilize the injection or placement of a radioactive tracer into the tumor

prior to surgery. This is in contrast to the current gold standard of wire-guided

localization, which utilizes the pre-operative placement of a wire into the non-

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palpable lesion. ROLL utilizes Tc-99 while RSL utilizes a titanium seed

containing Iodine-125.151 Gamma tracers are then used to localize the radiation

signal in the operating room and thereby improve resection of otherwise difficult

to detect tumors.

A technique which has become recently available which does not use

ionizing radiation or rely on any exogenous agents is margin detection by

electrical properties of tissue. A number of recent studies have shown that a

device called the MarginProbe® can differentiate cancerous from healthy tissue

so as to allow the detection of positive margins.153, 154 This technology relies on

differences in the membrane potential, cellular connectivity, and vascularity of

cancer cells and tumors. Results showed that more positive margins (PMs) were

detected using this technique than with visual inspection and palpation alone,

resulting in few resections. However, false positive rates were higher among

patients who’s lumpectomies were examined with the device.153, 154 Nonetheless,

the potential identify PMs without relying on delivery exogenous contrast agents

may prove extremely useful alone or in addition to additional methods of PM

detection such as fluorescence imaging.

4.0 Fluorescence Imaging and Image Guided Sugery

Fluorescence based imaging in oncology is a growing field in both

research and clinical practice. Cancer diagnosis using endogenous and

exogenous porphyrins date back to 1924 and 1942 respectively.132 The use of

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fluorescence in image guided surgery dates back to 1948, when fluorescein was

observed to improve the detection of brain tumors.155 This methodology requires

three broad aspects for use: fluorescent contrast agents that accumulate in target

tissues to sufficiently high levels for both detection and contrast, an excitation

light source, and a light collection device capable of capturing both emmitted

fluorescence and reflected visible light for anatomic localization. Of particular

interest is NIR fluorescence imaging, which exhibits lower autofluorescence and

tissue interference compared to other wavelengths, and is already in clinical

use.132 The methodologies, technologies, and recent experimental advances of

oncologic fluorescence imaging are discussed here in detail.

The Clinical Need for Image Guided Surgery

Surgery is one of the most common and effective forms of cancer

treatment, being used in the majority of solid tumor cases. Between 63-98% of

either lung, breast, bladder, or colorectal cancer patients will receive surgery,

depending on type, grade, and age at diagnosis.156 Prostate cancer patients are

also commonly treated with surgery, with surgery being chosen as part of

intervention for between 6-57% of patients, depending on age, with younger

patients being more likely to receive surgery. Surgery also offers the only option

for curing colorectal metastases to the liver.157 These cancers are among the

most commonly occurring forms, and therefore it is not difficult to see that the

majority of cancer patients in the US receive some form of surgical treatment. It

is commonly understood that in most types of cancer it is not the primary tumor

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that is the ultimate cause of death, but rather metastases that lodge in numerous

critical areas which then grow and shut down necessary physiological functions.

It is therefore critical that the primary tumor, local metastases, and metastatic

lymph nodes are removed prior to distant metastasis. However, much of the

intraoperative detection of tumors relies on visual and tactile differentiation of

healthy and diseased tissue, resulting in significant levels of residual cancer cells

and undetected metastases.

PMs are residual cancer found at the borders of surgically removed tissue,

and pose a significant health risk. Approximately 30% of breast cancer patients

will experience recurrence of disease locally or systemically.158, 159 Rates of PM

occurrence are estimated to be between 20-40% for patients receiving breast

conserving surgery.160 For hepatic resection of colorectal metastases the

intrahepatic recurrence rate is 11-37.5%, overall recurrance is as high as 40-

50%, and PMs are observed in 2-5% of patients.161, 162 Importantly, in patients

receiving both chemotherapy and surgical treatment for colorectal metastases to

the liver, PMs have been identified as the only risk factor for patient survival that

is associated with the surgery itself.163, 164 PMs also occur in 11-38% of patients

receiving radical prostatectomy and are a strong negative predictor of recurrence

and patient survival.165-167 While some new imaging modalities such as

Cherenkov luminescence imaging may provide ways to detect PMs more

effectively,168 current methods of detecting tumor margins intraoperatively involve

palpation and visual inspection. These are characterized by poor tissue contrast

and spatial resolution and lack detection nonpalpable lesions.151, 152 Traditional

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imaging modalities such as radiography, MRI, PET, SPECT, and US, typically

involve instrumentation that is too cumbersome or dangerous to use in the

surgical theater, or are incapable of providing tumor-specific information with high

contrast or resolution.120 To combat these limitations, a number of image guided

modalities are currently under investigation. These include US, MRI, and optical

fluorescence using both endogenous and exogenous fluorophores.169-171

Physics and Chemistry of Fluorescence

Photon emission from molecules and atoms occur when electrons are

excited above the ground state energy level and subsequently transition back to

the ground state by emission of a photon of energy equal to the difference

between the excited and grounds states, as shown in Equation 1.1,

������� = ℎ = ��� �� − ������� [1.1]

where ℎ is Plank’s constant and is the photon frequency. This representation is

inexact because both the ground and excited energy levels have additional

thermal or vibrational energy levels within them. A Jablonski diagram is shown in

Figure 1.3 illustrating the absorbance excitation and fluorescence emmision of

photons by electrons.

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Figure 1-3. Jablonski diagram showing photon absorbance and fluorescence

emission, designated ℎ� and ℎ� respectively. Absorbance occurs when a

photon of energy ℎ� is absorbed by an electron. The electron then undergoes

vibrational relaxation as designated by the green dashed arrow, and emits a

photon of energy ℎ� to another vibrational energy level within the ground state.

Fluorescence is differentiated from phosphorescence specifically by the

electron spins in the excited state.172 In fluorescence, the electron is in a singlet

state, with opposite spin to the paired electron in the ground state orbital. With

both electrons having opposite spin, return to the ground state from the excited

state is allowed and occurs with a rate of approximately 108 s-1. In contrast,

phosphorescence occurs when the excited state electron has the same spin as

the paired electron in the ground state orbital, thus preventing rapid photon

emission and return to the ground state. Phosphorescence excited state lifetimes

occur on the order of 103 to 1 s-1, many millions of times slower than

fluorescence. It should be noticed that the emitted photon is generally of lower

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energy, and thus higher wavelength, than the absorbed photon. This phenomon

is called the Stokes shift, and results from thermal relaxation of the electrons

within a single energy level without photon emission. Additionally, the electrons

generally do not transition to the lowest thermal energy level of the ground state

during emission.

Photon emission is usually independent of the excitation wavelength, a

phonomenon known as the Kasha-Vavilov rule. This results from the rapid

relaxation of electrons in excited states through non-radiative thermal relaxation

within the excited state. Thus, all excited electrons transition to the ground state

from identical engergy levels in the excited state. The emission spectra is often a

mirror image of the absorption spectra. This phenomenon results from the

similarity between the thermal energy levels within both excited and ground

states, for example the spacing between the thermal energy levels E1 and E0 in

Figure 1-3. Photon absorption occurs from the lowest E0 level to various thermal

levels within E1, and photon emission occurs from the lowest E1 level to various

thermal levels within E0. Thus, as the thermal spacings are similar between E1

and E0, energy transitions of photon absorption and emission must be equally

similar, resulting spectral symmetry.

Fluorescence Imaging in Cancer

Biomedical fluorescence imaging is concerned with wavelengths in the

visible spectrum, from approximately 400-700 nm, and the NIR spectrum from

approximately 700-900 nm. Commercially available fluorophores are available for

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a large number of excitation and emission peaks. For research purposes, most

are found in the visible spectrum. However, due to tissue autofluorescence and

high absorbance of visible spectrum light, in vivo imaging is better suited to NIR

fluorescence. Wavelengths below 700 nm are strongly absorbed by endogenous

molecules such as hemoglobin and myoglobin, while water and lipids absorb

strongly above 900 nm.173, 174 These phenomena create the “NIR window” from

700-900 nm in which photon absorbance is minimized and scattering is

maximized, allowing for greater depth penetration.

There are currently two FDA approved NIR fluorophores: indocyanine

green (ICG) (ex. 785 nm; em. 820 nm) and methylene blue (ex. 665 nm; em. 700

nm). ICG is of greater interest than methylene blue as the excitation and

emission wavelengths show less tissue absorption and it has a greater quantum

yield.171, 175 Outside of image guided surgery, ICG is used clinically to measure

cardiac output, hepatic function, and retinal angiography.171 Within image guided

surgery, ICG has been used for multiple oncological indications, including SLN

mapping and identification of solid tumors. A number of additional contrast

agents are currently being investigated, including several other cyanines such as

Cy5.5, Cy7, Cy7.5, IR-dyes (LI-COR, Lincoln, NE.), nanparticle formulations, and

visible spectrum dyes.176 Some examples are shown in Figure 1-4.

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Figure 1-4. Examples of NIR fluorescing dyes include the FDA approved ICG

(ex. 785 nm, em. 820 nm) and methylene blue (ex. 665 nm, em. 700 nm), as well

as investigational cyanines Cy5.5 (ex. 673 nm, em. 707 nm) and Cy7.5 (ex. 788

nm, em. 808 nm).

SLN mapping and biopsy is often used in an effort to detect metastatic

disease, but proper identification of lymph nodes draining from the tumor, SLNs,

must be achieved with high precision. Current methods utilize the visual dye

Patent blue or gamma probes, or a combination of both.177 The use of ICG in

SLN mapping is recent but becoming well established. Use of ICG as a color dye

has shown SLN detection rates of approximately 74%, while use of ICG

fluorescence has resulted in detection of nearly 99% of SLN in breast cancer

patients.171 Additional work is required to identify the false negative rates in these

patients, with a current best estimate of 7.7%. A number of clinical studies have

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also shown success in SLN mapping with ICG in cervical, vulvar, and

endometrial cancers.170 Similar success rates of SLN detection occur for skin and

gastric cancers. However, gastric and colorectal cancers may exhibit higher false

negative rates when ICG is used, depending on tumor grade and location.

Studies in patients with breast, skin, gastro-intestinal, lung, cervical, esophageal,

and other cancers have shown high rates of SLN detection.171, 178-180 Studies that

compare ICG fluorescence to the gold standard of radioisotope identification

show that ICG fluorescence alone is comparable to radioisotope identification,

and is just as effective when used in combination with radioisotope

identification.178, 180 While further work is needed, these initial studies suggest

that IGC could provide equivalent, lower cost, and safer SLN detection than

radioisotope administration.

Breast cancer imaging using ICG fluorescence has proven successful

using diffuse optical tomography (DOT). Studies have shown good overlap in

tumor localization between Gadolinium-enhanced MRI, palpation, and ICG, and

ICG may also be able to differentiate tissue pathologies.181, 182 DOT imaging

using pharmacokinetic rate images over time may also allow for improved

diagnoses.183 Another study has shown it may be possible to utilize ICG in

fluorescence mammograms. This study showed that in 21 patients fluorescence

ratio mammograms gave sensitivity and specificity of 84-100% and 59-91%

respectively.184 In contrast, conventional mammography has 100% and 9-41%

sensitivity and specificity. These results suggest that ICG fluorescence gives

similar tissue differentiation potential to some conventional imaging modalities

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and could serve to reduce false positive diagnoses. However, DOT and

fluorescence mammography provide low contrast due to the depth of the imaging

process, suggesting that fluorescence imaging may yield even better results

when performed during surgical resection when the imaging depth is decreased.

Image guided surgery (IGS) using ICG to delineate tumors in humans has

shown a number of preliminary successes, with most investigations examining

the procedure in hepatic carcinomas. Gotoh et al. used intravenous injections of

0.5 mg/kg ICG between 1-8 days prior to surgery and found that ICG

fluorescence successfully identified 100% of primary tumors and in 40% of the

cases also identified additional hepatocellular carcinomas that went undetected

either preoperatively or by intraoperative US.185 These additional nodules were

small, ranging from 3-6 mm in diameter. Another study examined the detection

capacity of combined imaging with ICG fluorescence and intraoperative US with

microbubbles compared to contrast enhanced CT/MRI, and found that the

combined fluorescence-US method had higher sensitivity, accuracy, and positive

predictive value than contrast enhanced CT/MRI.186 Similar to these studies, IGS

using ICG has also been shown to identify both hepatocellular carcinomas and

colorectal liver metastases, and to differentiate the two by fluorescence

pattern.187 This study showed that ICG had 100% success in identifying lesions,

some of which were not evident unless imaged by ICG, and hepatocellular

carcinomas showed uniform fluorescence while colorectal liver metastases

showed only rim fluorescence. The mechanism of ICG fluorescence localization

within hepatocellular carcinomas has recently been investigated and appears to

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result from a combination of features including cancer cell differentiation and

expression of proteins that contribute to portal uptake.188 ICG has also been used

clinically to image hemangioblastomas, where it has been found to be useful in

identifying vasculature feeding the tumors as well as hidden vessels.189

The use of other fluorophores in image guided surgery for additional

cancers has also met with clinical success. A phase III multicenter clinical trial

investigating the use of fluorescence IGS for glioma patients showed significantly

higher levels of complete tumor resection (90% vs 36%) and 6 month

progression-free survival (41% vs 21%) when compared to conventional surgery

conducted only with white light.190 The use of 5-aminolevulinic acid in this study

is interesting, as the molecule itself is not fluorescent but leads to accumulation

of endogenous fluorescent porphyrins. This method requires lower wavelength

(violet-blue) excitation and thus both excitation and emmission exhibit higher

absorption than if NIR fluorescence was used. In another study, folate-FITC was

used as a targeted contrast agent for ovarian cancer, and resulted in significantly

more tumors being identified than using white light alone.122 Additionally,

fluorescence intensity was qualitatively correlated with folate receptor-α

expression and tumor grade, indicating successful active targeting.122 These

studies both show the exceptional ability of fluorescence IGS to assist surgeons

in diseased tissue identification. However, FITC (ex. 495 nm; em. 520 nm) and

endogenous porphyrins both have absorptions and emissions outside of the

optimal NIR window. The potential for delivery of NIR fluorophores to these solid

tumors would likely improve the potential for complete resection even further.

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Fluorescence Image Guided Surgery Instrumentation

A number of image guided surgery systems are currently available, in

clinical trials, or under investigation.170, 191 These instruments are composed of

an excitation source, generally either a laser or LED system, for excitation of

fluorophores, and light collection system that preferably provides both white and

NIR image capture for overlay of the fluorescent signal onto the anatomical field,

as shown in Figure 1-5. Additionally, the use of a handheld excitation source

may also allow for spectral collection, providing a secondary means of signal

detection.

Figure 1-5. Schematic diagram of image guided surgery with instrumentation

showing channels for white (anatomical), laser, and NIR fluorescence. Image

overlay allows for simultaneous viewing of fluorescent signal on the anatomical

field for precise localization of cancer tissue. In this system, excitation is provided

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by a handheld laser that also features fluorescent and Raman spectral collection,

which may provide a further means of signal detection that is independent of the

filtering parameters used in the camera system. Used with permission from Mohs

et al. IEEE Biomedical Engineering, 2015.

Excitation light sources and wavelengths will depend on the contrast

agents used, highlighting the interdependency of the contrast agents and

instrumentation used. The light source must be powerful enough to give strong

fluorescence signal in the surgical field, while maintaining a working distance for

the surgery itself.192 LED sources are capable of illuminating the entire field of

view, but heat dissipation and adequate fluence are a concern. Laser excitation

is another option, which allows for greater surgical control but requires personal

protective goggles and there are concerns regarding patient exposure.176 Field of

view must be sufficient and adjustable for the surgeon to adequately capture the

surgical field, and must be illuminated by a light source that does not overlap with

the fluorescence signal. The collection optics and camera system are important,

as signal loss by cameras due to low quantum efficiency and resolution loss will

significantly affect the imaging potential.176 Currently there is no gold standard in

NIR fluorescence imaging, and further studies are required to determine optimal

system requirements and contrast agents.

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5.0 Fatty Acid Synthase in Cancer

Biology of FASN

Lipid synthesis is a crucial part of cell growth and operation, as lipids are

required for cellular membranes, modifying certain proteins, and energy storage.

Two sources are available for cells acquiring new lipids: circulating dietary lipids

and de novo synthesis from precursor molecules. Most healthy cells utilize

circulating lipids for structural lipids. However, nearly all cancers show increased

de novo fatty acid synthesis, regardless of the level of circulating dietary lipids.193

The key protein responsible for this process is the homodimeric, multienzyme

fatty acid synthase (FASN), which cyclically produces 16-18 carbon fatty acids

from multiple catalytic sites, using malonyl-CoA, acetyl-CoA, and NADPH.194

The primary product of FASN is the 16-carbon fatty acid palmitate. In

healthy liver and other lipogenic tissues, palmitate is typically produced only to

store excess energy in the form of triglycerides, and is regulated by dietary

intake.193, 195 However, the activity of FASN and fate of palmitate is different in

cancerous tissue, where the predominant product is phospholipids, the primary

class of lipids found in cell membranes. Regulation of FASN in these cells is

typically independent of the level of circulating fatty acids.193, 195 Evidence is

accumulating that this activity of FASN confers a survival advantage to cancers

and their precursor lesions, indicating its status as an oncogene and possibly a

hallmark of cancer.193, 196, 197 Increased expression of FASN has been shown in

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every major cancer type and it has been recognized for some time as a potential

target for therapy.195, 197

Utilization of FASN in de novo fatty acid synthesis may be related to

another hallmark of cancer, the Warburg effect.193 This is the increased aerobic

glycolysis, which many cancers show, that results in the conversion of glucose to

lactate.198 Both pyruvate and glucose-6-phosphate are upstream in the pathway

of FASN catalyzed lipid synthesis, as shown in Figure 1-6. Pyruvate is converted

to citrate by the citric acid cycle, and further to acetyl-CoA by ATP citrate lyase

(ACLY), then to malonyl-CoA by CoA carboxylase (ACACA). Both of these

enzymes contribute to the lipogenic phenotype that ultimately results in FASN

catalyzed production of lipids, which are eventually converted into membrane

lipids for increased proliferation.

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Figure 1-6. FASN primarily synthesizes palmitate from malonyl-CoA and acetyle-

CoA. Upstream contributors of FASN metabolites result from the increased

uptake of glucose as a result of the Warburg effect. Citrate is converted to acetyl-

CoA by the enzyme ACLY and further to malonyl-CoA by ACACA, both of which

may be upregulated in the lipogenic phenotype. Used with Macmillan Publishers

Ltd: Menendez et al., Fatty acid synthase and the lipogenic phenotype in cancer

pathogenesis, Nature Reviews Cancer, 2007, 7(10).

FASN Inhibitors and ORL

A number of molecules that target FASN have been investigated, among

which are Orlistat (ORL), cerulenin, C75, epigallocatechin gallate, and

triclosan.197, 199-202 However, cerulenin is chemically unstable and C75 possesses

side effects including severe weight loss and anorexia.195, 201 Thus, new

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molecules and formulations are needed that cause less collateral damage. As

has been seen previously with other drugs with dose limiting toxicity, a NP

formulation may help to reduce toxicity and improve delivery to tumors.

ORL, shown in Figure 1-7, will be the drug of focus for CHAPTER 5 of this

body of work. ORL is an FDA approved weight loss drug that, when taken orally,

binds specifically to gastric and pancreatic lipases.203 In addition to the lipase

activity however, ORL has been shown to be a potent inhibitor of FASN, where

ORL binds to the thioesterase within the enzyme, leading to the hydrolysis of the

β-lactone group within ORL and formation of a covalent bond between FASN and

ORL.204-206 In cellular assays ORL has been shown to effectively inhibit FASN by

inhibiting 14C-acetate uptake into fatty acids, reducing cancer cell proliferation as

well as endothelial cell proliferation and angiogenesis.206-208 In addition to FASN

inhibition, there is also evidence supporting additional effects such as cell cycle

disruption resulting in apoptosis.209, 210 In vivo models have shown reductions in

tumor growth, metastasis, and angiogenesis using a number of tumor models.211-

214 However, due to the high hydrophobicity of ORL, all in vivo models to date

have required administration either orally or via intraperitoneal injection. The

structure of ORL shows a very hydrophobic molecule, and indeed its log(P) is

predicted to be 7.3.215 Oral administration of ORL shows very low absorption,

with enteric elimination accounting for approximately 96% of the total dose and

urinary recovery accounting for 1.1%.203, 216 Additionally, ORL is degraded after

absorption resulting in two major metabolites that account for 42% of systemic

ORL content.216 Due to this high hydrophobicity, low absorption, and poor

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metabolic stability, a means of stabilizing and solubilizing ORL is needed to

improve its biodistribution and delivery to solid tumors.

Figure 1-7. Orlistat (MW: 495.74) is FDA approved for oral administration as a

weight loss drug that acts by inhibition of gastric lipases. ORL is also an inhibitor

of FASN, and has been shown to reduce tumor growth when administered by

intraperitoneal injection in mice. Improving solubility and metabolic stability may

allow for intravenous injection and improved delivery for use as a cancer-

targeting chemotherapeutic.

6.0 Conclusions

The body of research into nanoscale materials for biomedical application

clearly indicates that there is a current and future place for this technology in

medicine. Drug and contrast agent delivery using NPs has already found a place

in clinical medicine, and the share of these pharmaceuticals in the market is likely

to increase with the current formulations in pre-clinical and clinical investigations.

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Among the many possible uses, drug and fluorescent contrast agent delivery to

solid tumors are of high importance. It has already been seen that NP

formulations can improve the total quantity of drug delivered to tumors, and

perhaps equally important, they can also reduce associated toxicities and

thereby lessen the already high burden placed on patients dealing with

chemotherapy. Delivery of fluorescent contrast agents is a new but urgently

needed area. Current surgical practices do not adequately identify the extent of

solid tumors, local metastases, and sentinal lymph nodes, resulting in disease

recurrence. It is therefore crucial that new technologies are developed and

moved into the clinic that assist surgeons in the identification of these tissues.

In the following chapters, we will examine research into nanoscale

polymeric micelles derived from the natural glycosaminoglycan HLA, and the

application of these NPs to the delivery of indocyanine green for image guided

surgery, and ORL for chemotherapeutic delivery. We first outline the chemistry

behind the synthesis of these NPs, followed by the development and application

of ICG-loaded NPs both in vitro and in vivo. We then turn our attention to the

loading of the FASN inhibitor ORL into these HLA NPs to create a new

therapeutic formulation and examine in detail the in vitro efficacy against a

number of cancer cell lines.

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CHAPTER 2

SYNTHESIS OF NOVEL HYALURONIC ACID DERIVED NANOPARTICLES

Text and the following figures: Scheme 2-1, Figure 2-1, Figure 2-2, and data in

Table-2-1, have been reproduced with permission from Hill, T.K. et al.,

Indocyanine Green-Loaded Nanoparticles for Image-Guided Tumor Surgery.

Bioconjugate Chemistry 26(2), 2015. AFM analysis was performed with the

assistance of Dr. Adam Hall and Osama Zahid.

1.0 Introduction

In order to develop self-assembled NPs that use HLA as a hydrophilic

backbone material it is necessary to conjugate hydrophobic ligands directly to

HLA in order to drive self-assembly. Hydrophobic moieties bearing carboxylic

acid groups (1-pyrenebutyric acid, 5β-cholanic acid) were used as starting

products for synthesis of hydrophobic ligands. Addition of 1,3-diaminopropane to

these was performed in order to produce a product bearing a primary amine for

conjugation to HLA, resulting in the products aminopropyl-1-pyrenebutanamide

(PBA), and aminopropyl-5β-cholanamide (5βCA). Octadecylamine (ODA) was

also used to gain insight into the behavior of conjugates with varying hydrophobic

ligand structures. Synthesized products were analyzed by mass spectrometry

and NMR. Hyaluronic acid polymers were conjugated to one of these three

different hydrophobic ligands at different ratios in order to drive self-assembly

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into NPs. Conjugates were then analyzed by NMR to confirm conjugation, and

subsequently by dynamic light scattering (DLS) and AFM to confirm presence

and size distributions of NPs.

2.0 Materials and Methods

Materials

1-Pyrenebutyric acid, octadecylamine, 5-beta cholanic acid, 1,3-

diaminopropane, N-hydroxy succinimide, and 1-ethyl-3-(3-

dimethylaminopropyl)carbodiimide (EDC), ICG, and fetal bovine serum (FBS)

were obtained from Sigma-Aldrich (St. Louis, MO). Unless otherwise noted, all

water was obtained from a Barnstead NANOpure Diamond (Thermo Scientific;

Waltham, MA) system producing 18.2 MΩ water. Sodium hyaluronate was

purchased from Lifecore Biomedical (Chaska MN). Methanol, and N, N

dimethylformamide (DMF) were purchased from Fisher Scientific (Pittsburgh,

PA). Ethanol was purchased from the Warner-Graham Company (Cockeysville,

MD). Matrigel was purchased from BD Biosciences (San Jose, CA).

Penicillin/streptomycin and other media reagents were purchased from ATCC

(Manassas, VA).

Aminopropyl-1-pyrenebutanamide Synthesis

1-Pyrenebutyric acid (1.93 mmol, 558 mg) was dissolved in 5.5 ml MeOH

with 3% concentrated HCl and refluxed for six hours at 60-65 °C in a 25 ml round

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bottom flask (RBF). The reaction solution produced two layers; the top layer was

clear and light yellow, while the bottom layer was dark and oil-like. The top layer

was removed and the product, 1-pyrenebutyric methyl ester, was confirmed in

the bottom layer and dried under vacuum. 1-pyrenebutyric methyl ester (0.881

mmol, 266.4 mg) was then dissolved into 6 ml 1,3-diaminopropane and refluxed

at 130 °C for six hours to produce a clear, brown liquid. This solution was then

cooled to 0 °C and PBA was precipitated by cold water, washed in cold water,

and dried under vacuum. This process produced 0.52 mmol (180 mg, 59% yield).

A schematic of all the synthesis and conjugation used is shown in Scheme 2-1.

Scheme 2-1. (A) Synthesis of hydrophobic amides using 1-pyrenebutyric acid 5-

β-cholanic acid involves addition of MeOH followed by substitution with 1,3

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diaminopropane. (B) Conjugation of hydrophobic moieties, PBA, 5βCA, or ODA,

to HLA via EDC/NHS reaction.

Aminopropyl-5β-Cholanamide Synthesis

5-beta cholanic methyl ester was prepared according to the methods

described in the literature.217 Briefly, in a 25 ml RBF, 5-beta cholanic acid (2.8

mmol, 1.0 mg) was dissolved in 5 ml methanol. To the RBF, 180 µl of

concentrated HCl was then added under stirring and this solution was allowed to

reflux at 60-65 °C for 6 hours. The product was cooled to 0 °C and appeared as a

white precipitate. The precipitate was collected under vacuum filtration, washed

with cold methanol, and then dried under vacuum. 0.80 mg of 5-beta cholanic

methyl ester was recovered (2.1 mmol, 75% yield). 5βCA was synthesized by

dissolving 5-beta cholanic methyl ester (1.36 mmol, .51 mg) in 132 mmol (~11

ml) of 1,3-diaminopropane. This solution was refluxed at 130 °C for 6 hours and

then allowed to cool to 0 °C. 5βCA was obtained from crystallization with water.

The white precipitate was then washed with 200 ml cold nanopure water under

vacuum filtration and dried under vacuum to produce 0.952 mmol (.397 mg, 70%

yield).

Conjugation of 5βCA or PBA to HLA

Sodium hyaluronate (90-95 mg, MN = 10-20 kDa), was dissolved in 25 ml

of water. PBA at 5 or 10 wt% (14 or 28 mmol, 5 or 10 mg), or 5βCA at 5 or 10

wt% (12 or 24 mmol, 5 or 10 mg), was dissolved into 25 ml DMF under stirring at

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30-40 °C. NHS and EDC, 78-154 mmol (10X molar ratio to PBA or 5βCA), were

then dissolved into the HLA solution. The PBA or 5βCA DMF solution was then

added dropwise to the activated HLA solution under constant stirring. The

reaction was allowed to stir until completion at room temperature, 24-36 h. The

reaction contents were then transferred to dialysis tubing (material: MWCO =

3500 Da, Spectrum Labs) and allowed to dialyze against 1:1 EtOH:H2O for 24 h

followed by H2O for an additional 48 h. The polymer-hydrophobic moiety

conjugate was removed from the dialysis tubing and lyophilized for storage at -20

ºC. This process produced High-PBA-HLA (10 wt% PBA), Low-PBA-HLA (5 wt%

PBA), High-5βCA-HLA (10 wt% 5βCA), and HLow-5βCA-HLA (5 wt% 5βCA).

Conjugation of ODA to HLA

ODA (9.3 mmol, 2.5 mg) was dissolved into a 70% EtOH:H2O solution.

HLA, 97.5 mg, was dissolved into a separate solution of 70% EtOH:H2O and 10-

fold molar excess of EDC and NHS were then added. The ODA solution was

then added slowly into the HLA solution under vigorous stirring and the reaction

was allowed to proceed for 24-36 h at room temperature. The reaction mixture

was then dialyzed (material, MWCO = 3500 Da, Spectrum Labs) against 1:1

EtOH: H2O for 24 hours and water alone for 48 h. This material, ODA-HLA

(2.5wt% ODA), was then lyophilized and stored at -20 ºC.

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Hydrophobic Conjugate Characterization

The PBA and 5βCA intermediate methyl ester products were analyzed by

GC-MS with a Thermo Scientific Trace Ultra gas chromatograph interfaced with a

Thermo Scientific TSQ Quantum XLS (Thermo Scientific; Waltham, MA) using

splitless injection. Separation was performed on a 10.4 m DB-1 WCOT column

(Agilent Technologies Inc.; Santa Clara, CA). PBA and 5βCA were analyzed on a

Waters Q-Tof API-US mass spectrometer with Advion TriVerso NanoMate

(Advion Biosystems; Ithaca, NY) using positive ion electrospray. 5βCA-HLA,

PBA-HLA, and ODA-HLA conjugates were analyzed on a Bruker Avance 600

MHz NMR spectrometer with TXI Cryoprobe at 25º C, with 64 to 128 scans, 8192

to 16384 data points, and 10-12 second relaxation delay. 5βCA-HLA and PBA-

HLA were analyzed in 50/50 D2O/DMSO-D6 (D2O from Acros Organics “100.0%”

D, Fisher Scientific, DMSO-D6 from Cambridge Isotope Labs, 99.9% D). Data

was processed in Mnova NMR (Escondido, CA).

Confirmation of NP Formation

Crosslinking of NPs with diaminopropane was performed here strictly to

form a material that did not disassemble upon drying, thus making analysis by

AFM possible. NPs were not crosslinked in any other part of this experiment

work. High-PBA-HLA NPs were exposed to 0.30 mol fraction diaminopropane,

relative to the repeat unit of HLA, in presence of 10-fold molar excess of

EDC/NHS, and this solution was incubated at room temperature overnight in

order to crosslink the self-assembled NPs, and thereby prevent disassembly. The

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hydrodynamic diameter of this material was then analyzed by DLS using a

ZetaPlus system with an onboard dynamic light scattering (DLS) analyzer

(Brookhaven Instruments Corporation; Holtsville, NY). For AFM analysis, NPs

were dispersed into water at 1 mg/ml. 20 µl of this solution was then placed on

the center of a mica plate which had previously been cleaned by repeated

application of standard scotch tape. Solution was then dried under light air flow

and examined using MFP3D AFM (Asylum Research, Santa Barbara, CA.)

operated in tapping mode.

3.0 Results and Discussion

Hydrophobic Moiety Synthesis and Conjugation to HLA

Three structurally distinct hydrophobic moieties were examined to

determine their effect on driving self-assembly and ICG loading. 5β-cholanic acid

and ODA have previously been reported to successfully drive self-assembly

when conjugated to HLA,50, 51, 218 while PBA has not been previously conjugated

to HLA. Scheme 2-1 shows the reaction. 1-Pyrenebutyric acid and 5β-cholanic

acid were refluxed in methanol to give 1 and 2, respectively. Next, methyl esters,

1 and 2, were converted to amide products, PBA and 5βCA, respectively, by

refluxing 1,3-diaminopropane as shown in Scheme 2-1A. PBA and 5βCA each

possess a primary amine moiety for conjugation to HLA. Since PBA is previously

unreported, mass spectra and 1H-NMR of this product is shown in Figure 2-

1A&B. The structural characterization of 5βCA is shown in Figure 2-2A. ODA

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was used as provided for conjugation to HLA. Conjugation of the primary amine

group on PBA, 5βCA, or ODA to the carboxylic acid group of the glucuronic acid

moiety was performed using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide

hydrochloride (EDC) and N-hydroxysuccinimide (NHS) chemistry to facilitate

amide bond formation (Scheme 2-1B).

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Figure 2-1. Confirmation of synthesis of novel compounds. Mass spectrometry

(A) and 1H-NMR (B) confirmed the synthesis of PBA. (C) Quantification of

conjugation of PBA to hyaluronic acid was achieved by calculating the ratio of

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aromatic pyrene protons relative to the N-acetyl protons (a) on N-acetyl-D-

glucosamine of hyaluronic acid.

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Figure 2-2. Confirmation of previously synthesized compounds. (A) MS of 5βCA.

1H-NMR of (B) HLA-5βCA and (C) HLA-ODA.

Conjugation of the hydrophobic groups to HLA was performed using

loading ratios of 5 wt% (Low) and 10 wt% (High) for PBA-HLA and 5βCA-HLA,

and 2.5wt% for ODA-HLA. Conjugation ratios with greater than 2.5 wt% ODA had

poor solubility and did not form NPs efficiently, while reducing the wt% of ODA

lowers the ligand-to-polymer ratio below 1:1. Successful conjugation was

observed for all products in the NMR spectra (Figure 2.1C, Figure 2.2B-C). This

synthesis produced amphiphilic HLA polymers with varying degrees of

substitution of hydrophobic moieties. Conjugation levels were quantified by NMR

and results are shown in Table 2.1.

Sample Theoretical hydrophobic moiety conjugation mol%a

Actual hydrophobic moiety conjugation mol%b

Low-PBA-HLA 5.8 5.67

High-PBA-HLA 12.2 10.1

Low-5βCA-HLA 4.8 3.88

High-5βCA-HLA 10.1 6.0

ODA-HLA 2.8 2.77

Table 2-1. Conjugation levels of hydrophobic conjugates to HLA. A) Molar

loading ratio, b) Calculated molar loading ratio determined by NMR integration

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In order to determine the diameter of these NPs, crosslinking of High-

PBA-HLA NPs was performed in order to maintain their structure upon drying.

AFM and DLS was then performed to determine the presence of NPs as shown

in Figure 2-3. It should be noted here that the crosslinking performed in Figure

2-3 was strictly used to determine NP diameter, and no other NPs presented in

this work were crosslinked. NPs at the scale predicted were clearly present in

both AFM and DLS analysis, and DLS analysis gave hydrodynamic diameters

consistent with those observed for other NP types, as will be discussed in

CHAPTER 3. NP diameters as measured by AFM using the cross-sectional

length were consistent with expected NP diameters from DLS. However, using

height analysis of the AFM data shows heights much smaller than expected,

ranging from 10-20 µm. This suggests that the NPs had undergone a significant

degree of dehydration that affected their total volume, and thus the diameters

obtained by AFM are not expected to conform with those observed in solution,

but rather this data should be interpreted only to confirm the existence of NPs

formed with these materials.

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Figure 2-3. AFM of crosslinked High-PBA-HLA NPs. NPs were crosslinked in

order to prevent disassembly upon drying, which had been previously observed.

Presence of NPs were confirmed by AFM and similar DLS distributions were

obtained for both crosslinked and non-crosslinked formulations, with effective

diameters of approximately 270 nm.

4.0 Conclusions

In this chapter we have examined the synthesis and conjugation of

hydrophobic conjugates to HLA. PBA is a novel conjugate not previously

examined and possesses several properties that have proved useful for future

studies with these materials. These properties are the aromatic, planar nature of

part of the molecule, which may allow for pi-pi stacking with other aromatic

molecules such as fluorophores, the higher wavelength absorbances from the

aromatic region that can allow for optical quantification of material, and more

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rapid solubility of material compared to 5βCA, which may provide more complete

conjugation to HLA. Other conjugates that have previously been examined were

also used, including 5βCA which was synthesized in house, and ODA which was

used as ordered. The conjugation of these materials to HLA was confirmed using

NMR, formation of NPs was confirmed using DLS and AFM, and further

confirmation of NP formation will be presented in CHAPTER 3. These materials

will form the basis of future investigations into NPs for image guided surgery and

drug delivery that will be examined in the following chapters.

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CHAPTER 3

IN VITRO CHARACTERIZATION OF INDOCYANINE GREEN-LOADED

NANOPARTICLES

Text and the following figures: Figure 3-1, data in Table 3-1, Figure 3-2, Figure 3-

3, Figure 3-4, Figure 3-5, Figure 3-6, and Figure 3-10, have been reproduced

with permission from Hill, T.K. et al., Indocyanine Green-Loaded Nanoparticles

for Image-Guided Tumor Surgery. Bioconjugate Chemistry 26(2), 2015.

1.0 Introduction

Detecting positive tumor margins and local malignant masses during

surgery is critical for long-term patient survival. The use of image-guided surgery

for tumor removal, particularly with near infrared fluorescent imaging, is a

potential method to facilitate removing all neoplastic tissue at the surgical site. In

this study we demonstrate a series of hyaluronic acid (HLA)-derived

nanoparticles that entrap the near infrared dye ICG, termed NanoICG, for

improved delivery of the dye to tumors. Self-assembly of the nanoparticles was

driven by conjugation of one of three hydrophobic moieties: PBA, 5βCA, or ODA.

Nanoparticle self-assembly, colloidal stability, dye loading, optical properties, ICG

release, cellular uptake, and cytotoxicity were characterized. ICG was found to

load into all NP formulations and was influenced by hydrophobic ligand structure.

Fluorescence was quenched in aqueous solution but could be reactivated by

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addition of an equal volume of DMSO or 37 mg/ml bovine serum albumin (BSA).

NPs were observed using DLS both with and without the presence of fetal bovine

serum, and ICG appeared to release from NanoICG when serum proteins were

present. Incubation of NanoICG with MDA-MB-231 cells resulted in cell-

associated fluorescence, but this appeared to be independent of whether the ICG

was localized in NPs. Cytotoxicity was found to be negligible at physiologically

relevant concentrations.

2.0 Materials and Methods

ICG Loading into Nanoparticles

Amphiphilic HLA polymer conjugate, 8-16 mg, was dissolved in 5 ml of

water, while ICG (.0026-.0052 mmol, 2.0-4.0 mg) was dissolved in 5 ml DMSO

and added to HLA solution. This solution was vortexed and then dialyzed against

H2O for 24-36 h to remove DMSO and drive self-assembly of ICG-entrapped

NPs. Resulting NPs were then filtered through a PD-10 desalting column (GE

Lifesciences; Pittsburgh, PA) to remove free ICG. The clear green solution was

then lyophilized and frozen at -20 °C until resuspension of NPs. Materials

produced by this process are termed High-PBA-NanoICG, Low-PBA-NanoICG,

High-5βCA-NanoICG, Low-5βCA-NanoICG, and ODA-NanoICG.

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Nanoparticle Characterization

NanoICG or empty NPs (empty NPs underwent same dialysis treatment,

but without ICG) were diluted to a concentration of 0.1 mg/ml in PBS and filtered

through a 0.45 um filter (Fisher Scientific; Pittsburgh,PA). The hydrodynamic

diameter (HD) of the NP-containing solutions was determined on ZetaPlus

system with an onboard dynamic light scattering (DLS) analyzer (Brookhaven

Instruments Corporation; Holtsville, NY). Absorbance (extinction) spectra were

obtained on a UV-2600 (Shimadzu Scientific Instruments; Columbia MD).

Fluorescence spectra were obtained on a FluoroMax-4 fluorescence

spectrometer equipped with a NIR extended range PMT (Horiba Jobin Yvon;

Edison, NJ). Spectra were obtained on aqueous solutions containing NPs and

disassembled NP contents by addition of an equal volume of DMSO. ICG-loading

content was determined with absorbance spectroscopy with a standard curve of

ICG in 1:1 H2O/DMSO.

NanoICG Serum Stability

Solutions of 3% v/v FBS, 3% FBS + 0.35 mg/ml High-PBA-HLA NanoICG,

or 0.35 mg/ml High-PBA-HLA NanoICG were made in PBS. Solutions were

incubated at room temperature for 10 minutes prior to start of analysis. Dynamic

light scattering using a Zeta-Plus instrument was performed as described

previously to determine if hydrodynamic diameter of NanoICG or serum proteins

changed in a mixed solution.

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Photostability

ICG and NanoICG were dissolved separately in pure water and aliquoted

into wells of an opaque 96 well plate (n = 3 each). ICG concentration of free or

NanoICG was approximately 0.0001 mg/ml (0.13 µM). Using the portable

fluorescence spectrometer with a fiber-coupled handheld (SciApps; Laramie,

WY), 785 nm, 300 mW laser light was directed into the wells for three iterations

of 10 seconds each. The fluorescence spectrum was taken after 0, 10, 20, and

30 seconds of cumulative exposure. The spectra were integrated from 797-977

nm to acquire the total signal present. Results were then averaged and

normalized to the initial pre-exposure spectra.

NanoICG Interaction with Serum Proteins

BSA was dissolved in PBS to 37 mg/ml, and NanoICG was dissolved into

the same solution at 1 mg/ml and either incubated at room temperature for 0 or 7

hours, or exposed to flow conditions. Exposure to flow conditions utilized a

circularly connected piece of 1/8 X 3/16 Tygon 3350 silicon tubing pumped by an

Ismatec Reglo peristaltic pump for continuous flow. Solutions were mixed and

then added immediately to the pump system, and flowed at rates of 0.1, 0.5, and

0.9 ml/s for one hour before stopping and immediate measurement of

absorbance from 500-900 nm.

Elution of ICG with serum proteins was performed by mixing either

NanoICG or free ICG with 37 mg/ml BSA in PBS, followed by incubation at room

temperature for either 0, 4, 8, or 24 hours. At the appropriate timepoint, solutions

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were taken and eluted through 100 kDa MWCO Amicon Ultra 2ml centrifugal

filter units at 3184 RCF for 30 min. Eluates were collected and examined using

absorbance spectroscopy from 500-900 nm. Original solutions were also

quantified for ICG and BSA content. Analysis was then performed by taking the

relative fractions of ICG and BSA that eluted through the filter, as shown in

Equation 3.1, followed by simple linear regression.

�������� ������ ! = "#$% ��&��'( ��� #$% ) / "+,- ��&��'

( ��� +,- ) [3.1]

In Vitro Cellular Uptake of NanoICG

500,000 MDA-MB-231 cells were seeded into each well of 6-well tissue

culture dishes and allowed to adhere overnight. Cells were split into 5 groups: (1)

unstained cells that received no treatment, (2) NanoICG-treated cells that

received 1 hour pre-incubation with 10 mg/ml free 10 kDa HLA as a blocker prior

to application of High-PBA-HLA NanoICG at 0.5 mg/ml (blocked), (3) NanoICG-

treated cells that were not exposed to free HLA (no blocker), (4) free ICG-treated

cells that received 1 hour pre-incubation with 10 mg/ml free 10 kDa HLA as a

blocker prior to application of 0.1 mg/ml free ICG, (5) free ICG-treated cells that

were not exposed to free HLA (no blocker). Free HLA was maintained in groups

(2) and (4) at 10 mg/ml over the course of the 1.5 hour incubation with either

NanoICG or free ICG. HLA pre-incubation and incubation with either NanoICG or

free ICG were performed in serum free media. After 1.5 hours of incubation with

either NanoICG or free ICG, cells were trypsinized from the plates and

centrifuged twice in PBS to wash. Groups were then analyzed on a FACSAria

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flow cytometer using a 760/80 nm bandpass filter with cell counts of

20,000/group.

Cytotoxicity

Cytotoxicity was evaluated by CCK-8 assay (Dojido, Japan). 2,000 MS1

mouse endothelial cells were seeded into 96 well plates and allowed to adhere

for 24 hours in EMEM (Gibco), 10% FBS (Sigma Aldrich), 1% P/S (Gibco). Cells

were then mixed with normal media containing High-PBA-HLA, High-PBA-

NanoICG, Low-PBA-HLA, Low-PBA-NanoICG, 5βCA-HLA, 5βCA-NanoICG,

ODA-HLA, or ODA-NanoICG at concentrations of 50 and 5 µg/ml. Cells were

incubated for 24 hours followed by analysis with CCK-8 assay. Proliferation of

MDA-MB-231 cells was analyzed using a FluoReporter Blue DNA quantification

assay (Life Technologies; Grand Island, NY). 2,000 MDA-MB-231 cells were

seeded into wells of tissue treated 96 well plates. The cells were exposed to

High-PBA-HLA or High-PBA-NanoICG at 5 µg/ml, for 24 hours. After the 24 hour

exposure standard media was applied. DNA was quantified at 0, 24, 48, 72, and

96 hours.

Statistical Analysis

Analyses of average NP size, ICG loading, photoprotective effect, and

cytotoxicity were performed with one-way ANOVA. Analysis of ICG-BSA elution

through 100 kDa filter membranes was analyzed with linear regression. Analysis

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of cellular uptake of ICG was performed in FlowJo software, while all other

analyses were performed using GraphPad Prism and Excel.

3.0 Results and Discussion

Such amphiphilic conjugates were necessary to drive self-assembly and

provide a hydrophobic domain for entrapment of ICG, as schematically depicted

in Figure 3-1A. Complete characterization of NanoICG formulations are shown in

Table 3-1, along with hydrophobic ligand conjugations as discussed in

CHAPTER 2 for reference. It was hypothesized that PBA could provide increased

loading efficiency for ICG compared to 5βCA or ODA, because of the potential

for π-π stacking between PBA and ICG.219 ODA is capable of efficient self-

association, but is not structurally similar to ICG. Each wt% of PBA and 5βCA

conjugates were found to load more ICG than ODA-HLA; ODA-HLA loading was

13-35% less compared to the other hydrophobic moieties. ICG loading into PBA-

HLA NPs was equal or higher than 5βCA-HLA. Loading efficiency (33-50%) and

ICG content (6-10 wt%) of NanoICG was moderate compared to previous ICG-

loaded NP formulations,220, 221 which range from very low loading efficiency (1-

10%) and content (0.16-0.21 wt%), to moderate,222, 223 and relatively high

efficiencies of 34-97% and content up to 23%.224 NanoICG with maximum ICG

content was used in order to minimize the total mass of nanoparticle required for

injection.

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Figure 3-1. (A) Hydrophobic moieties conjugated to HLA drive self-assembly into nanoparticles that can entrap ICG. (B)

NP diameters range from 80-260 nm, with smaller diameters observed in NanoICG formulations. (C) NanoICG

formulations increase ICG solubility in aqueous salt solution by providing a favorable electrostatic environment, while ICG

alone or not entrapped in NPs has poor solubility and precipitates rapidly.

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Sample Theoretical hydrophobic moiety conjugation mol%a

Actual hydrophobic moiety conjugation mol%b

ICG loading efficiencyc

ICG wt% Fluorescence activationd

Low-PBA-HLA

5.8 5.67 0.501 ± .004 10.0 ± .1% 31.7 ± 8.8

High-PBA-HLA

12.2 10.1 0.470 ± .004 9.4 ± .1% 28.2 ± 0.56

Low-5βCA-HLA

4.8 3.88 0.370 ± .003 7.4 ± .1% 22.3 ± 3.7

High-5βCA-HLA

10.1 6.0 0.475 ± .004 9.5 ± .1% 33.0 ± 1.2

ODA-HLA 2.8 2.77 0.327 ± .003 6.5 ± .1% 21.2 ± 3.1 Table 3-1. Characterization and ICG loading of HLA conjugates. a) Molar loading ratio, b) Calculated molar loading ratio

determined by NMR integration, c) ICG loading efficiency = (calculated ICG concentration measured by absorbance

spectroscopy)/(theoretical concentration based on loading amount), d) Fluorescence activation = [integrated fluorescence

intensity (790 – 950 nm) of NanoICG in 1:1 DMSO:H2O]/[integrated fluorescence intensity (790 – 950 nm) of NanoICG in

H2O]

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Physical, chemical, and optical characterization

Hydrodynamic diameters of empty NPs (i.e., those not loaded with ICG)

ranged from 150 to 260 nm, whereas NanoICG formulations ranged from 80 to

150 nm depending on the hydrophobic group (Figure 3-1B). Representative

histograms of DLS analyses are shown in Figure 3-2. NPs were observed at all

concentrations within the detection limits of the instruments used in this study.

NanoICG formulations increased the solubility of ICG in PBS, as was observed

by an optically transparent green color throughout the PBS solution;

centrifugation could not remove ICG from solution. The same quantity of ICG

alone or ICG mixed with previously assembled empty NPs in PBS was insoluble

and could be pelleted by centrifugation (Figure 3-1C). The size of NanoICG

remained consistent in FBS (Figure 3-3).

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Figure 3-2. Representative intensity-weighted (left) and number-weighted (right)

dynamic light scatter results from each HLA-hydrophobic moiety conjugate. Black

bars are nanoparticles that do not have ICG (empty nanoparticles); green bars

represent nanoparticles that have ICG entrapped.

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Figure 3-3. DLS histograms of NanoICG (top), FBS (bottom), and NanoICG

mixed with FBS. NanoICG and FBS has distinct distributions centered at

approximately 120 nm (hydrodynamic diameter) and 14 nm, respectively. Mixing

NanoICG in FBS resulted in a biomodal distribution with peaks occurring at 15

nm and 100 nm, representative of independent FBS and NanoICG populations

and a stable nanoparticle diameter in serum.

The absorbance and fluorescence spectra of ICG in DMSO showed peaks

near 800 and 825 nm, respectively (Figure 3-4A). The extinction spectra of

NanoICG showed strong scattering in pure water and PBS, likely due to

aggregation and electronic effects of ICG,219 suggesting the ICG was self-

associated within the NPs (Figure 3-4B). NanoICG fluorescence was quenched

in aqueous solution (Figure 3-4B). NanoICG disassembly was induced by the

addition of DMSO. The resulting absorbance and fluorescent spectra of ICG

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closely resembled its characteristic shape (Figure 3-4C), suggesting dye

release. The fluorescence signal after DMSO addition over the quenched state

for each NanoICG formulation is shown in Table 1. All NPs investigated showed

quenching and activation (Figure 3-5). Change in the absorption peak of ICG,

indicative of scattering by NPs is consistent with previous reports.221, 224

However, the fluorescence quenching observed in NanoICG (Figure 3-5) is

observed in only some formulations of encapsulated ICG previously reported in

the literature,221, 225 but not others.226 Nanoparticle entrapment of ICG did

provide a modest, yet significant increase in the photostability of ICG compared

to free ICG (Figure 3-6). The photoprotective effect is consistent with dyes

closely associated in a matrix.227

Figure 3-4. (A) ICG dissolved in DMSO shows clear extinction and fluorescence

peaks near 800 and 825 nm respectively. (B) Nanoparticle formulations of ICG

show broadened absorbance spectra with a less discernable peak due to

scattering by NP-entrapped ICG, and ICG fluorescence is quenched. (C) NPs

disassemble in 50:50 DMSO:H2O, decreasing the scattering in ICG absorbance

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and fluorescence activation, which demonstrates the potential for optical property

control.

Figure 3-5. Absorbance (left) and fluorescence emission (right) spectra of each

nanoparticle when dissolved in either water (blue) or 1:1 H2O:DMSO.

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Figure 3-6. Exposure of ICG (black circle) and High-PBA-HLA NanoICG (red

square) to a focused laser beam (785 nm, 300 mW) for 30 s. A modest, but

significant increase in photostability is observed with NanoICG compared to free

ICG. It should be noted that this laser power is 10 to 40 fold higher than what is

expected during intraoperative imaging, where the excitation is at a lower power

and not directly at the focal point of the laser.

Interestingly, when ICG was entrapped, the NP diameter decreased,

regardless of the hydrophobic conjugate. These data suggests that the

hydrophobic groups of amphiphilic HLA facilitates close association of ICG.

Close packing of ICG in NPs is further supported by the optical and colloidal

properties of NanoICG. First, the absorbance peaks of ICG, when loaded into

NPs, showed a decreased signal at ~795 nm and an increased scattering

contribution to extinction spectra (Figure 3-4B) when compared to ICG in DMSO

(Figure 3-4A). These finding are consistent with previously reported results.218,

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228 Second, fluorescence quenching was also observed in NanoICG formulations.

Finally, ICG becomes stable in high salt conditions when associated with

amphiphilic HLA conjugates. Taken together, the findings of the broad

absorbance of NanoICG, self-quenched fluorescence, and increased ICG salt

stability strongly suggest that ICG is being closely associated within NPs via

sequestration in hydrophobic domains. It is important to note that precise control

of quenching and activation may also prove useful for image-guided surgery if

high levels of fluorescence activation can be achieved specifically in the tumor

environment.224, 229

NanoICG Interaction with Serum Proteins

NanoICG was next analyzed for its stability in serum-like conditions. BSA

was dissolved to 37 mg/ml in PBS and High-PBA-HLA was dissolved in this

solution to a concentration of 1 mg/ml. Solutions were then exposed to a series

of flow conditions to simulate shear stress that would be experienced in vivo.

Absorbances from 500-900 nm were taken in order to observe the shape and

presence or absence of scattering around the ICG peak, and thereby gain insight

into the physical state of ICG. The data in Figure 3-7 shows the standard

NanoICG peak in PBS (black), with a decreased absmax and scattering indicative

of ICG present in NPs. Upon dissolution of NanoICG into BSA-PBS solution

(red), there is an immediate shift in the shape of the ICG spectrum, showing both

narrowing and increasing height of absmax. This trend intensifies with increasing

incubation time without flow (brown, 7 hours at room temperature), and with

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increasing volumetric flow rate with corresponding increases in WSS (green,

purple, blue). Quantitative analysis of this is shown in Table 3-2. Absorbance

peaks of various NanoICG formulations were compared when dissolved in either

DMSO-H2O or PBS-BSA solutions after flow, and results indicate that the

absorbance of ICG changes in an almost identical fashion when NanoICG is

dissolved in DMSO-H2O or PBS-BSA. This changing ICG absorbance spectrum

is indicative of a physical change in the proximity of ICG molecules to one

another. As ICG can bind reversibly to the hydrophobic pockets of serum

albumin, this trend likely results from changes in the physical location of ICG,

moving from a closely associated state within the NP core to a BSA-bound state.

Figure 3-7. Analysis of ICG absorbance change from NanoICG in flow conditions

with 37 mg/ml BSA. The increase in height and narrowness indicate a change in

the physical state of ICG, likely due to the release of ICG from the NPs to BSA.

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NP Type Ratio, NP in

DMSO/H2O to

H2O

Ratio, NP in

PBS/BSA to PBS

Ratio, Column 3

to Column 2

(Ratio = 1 is

perfect match)

High-5βCA 2.014433 1.984559 0.98517

Low-PBA 2.110204 2.218076 1.051119

High-PBA 1.823256 1.946606 1.067654

Table 3-2. Analysis of relative absorbance peak increases of NanoICG in either

DMSO-H2O or PBS-BSA solutions. Column 2 shows the ratio of peak heights

between NanoICG dissolved in DMSO-H2O or pure H2O. Column 3 shows the

ratio of peak heights of NanoICG dissolved in 37 mg/ml BSA in PBS, or PBS

without BSA. Column 3 shows the ratio of Column 2 to Column 3, where a value

of 1 indicates an equal change in absorbance between NanoICG in DMSO-H2O

or PBS-BSA. Similar optical features are observed with NanoICG is dissolved in

PBS containing physiological concentrations of BSA, indicating ICG is being

released to BSA.

In order to further test if ICG was releasing from NanoICG into BSA, we

attempted to separate BSA from the NPs by size filtration. NanoICG or ICG was

mixed with 36 mg/ml BSA in PBS and filtered at different timepoints through a

100 kDa MWCO protein filter in order to separate the BSA from the larger NP

complexes. The quantity of BSA and ICG present in the initial solutions were

measured with absorbance spectroscopy and the relative fractions of both ICG

and BSA that moved through the filter were quantified and compared. Thus, if the

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same fraction of ICG as BSA moved through the filter, then the relative fraction of

ICG:BSA would be 1.0, as shown in Figure 3-8. As the data indicates, when

either NanoICG or ICG are exposed to BSA solution, approximately the same

amount of ICG elutes with BSA. This data, combined with the absorbance

spectra changes observed when NanoICG is exposed to flow conditions, indicate

that NanoICG is likely releasing a substantial amount of ICG to bind serum

proteins. Further work is required to elucidate the exact dynamics of release.

Figure 3-8. ICG and NanoICG elute similarly in presence of BSA, indicating that

ICG loaded into NPs is likely being released to serum proteins in vitro.

In Vitro Cellular Uptake of NanoICG

Cellular uptake of NanoICG vs free ICG was analyzed by in vitro

incubation of MDA-MB-231 cells with either High-PBA-HLA NanoICG (Figure 3-

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9A) or free ICG (Figure 3-9B), either with or without 10 mg/ml free HLA present

as a blocking agent (Blue- with HLA, Red-without HLA). Results indicate that the

effect of blocking by 10 kDa HLA on the uptake of NanoICG was negligible, as

both blocked and unblocked NanoICG was taken up in cells at similar levels. The

same results were observed with free ICG, as no difference was observed

between cells that were exposed to free HLA. These results indicate that the

uptake of NanoICG by cells is not dependent on the presence of free 10 kDa

HLA. While much larger molecular weight HLA polymers are found in vivo, these

results indicate that the active targeting ability of NanoICG may be minimal.

However, active targeting of individual cells is not necessary for image guided

surgery purposes due to resolutions being too low to detect individual cells. It has

previously been shown that delivery of the majority of NP material to tumors

relies on passive targeting via the EPR effect, and thus the lack of active

targeting exhibited here is not likely to affect net delivery of ICG to the tumor

bulk.82

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Figure 3-9. Flow cytometry of MDA-MB-231 cells stained with either NanoICG

(A) or free ICG (B) with or without 10 mg/ml free HLA as a blocking agent (blue).

Results indicate there may be a slight be not meaningful blocking effect of free

HLA on the uptake of NanoICG, while uptake of free ICG by cells is not

associated with the presence of HLA in solution.

Cytotoxicity

MS-1 mouse endothelial cells were chosen to represent mouse

vasculature upon introduction of NPs. All NPs and NanoICG formulations did not

affect the metabolic activity of these cells at physiologically relevant

concentrations (i.e., 5-50 µg/ml of ICG) using a CCK-8 assay, as shown in

Figure 3-10A. Because High-PBA-HLA NanoICG was found to have the smallest

effective diameter and approximately equivalent or higher ICG loading than other

NPs, these were further investigated for their cytotoxicity to MDA-MB-231 breast

cancer cells. MDA-MB-231 breast cancer cells were chosen to determine the

A B

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effect on proliferation of target cancer cells. Proliferation of MDA-MB-231 cells

was not affected after a 24 h exposure to High-PBA-HLA NanoICG, suggesting

that the NPs do not have an effect on growth of target cell populations (Figure 3-

10B). The results are analogous to the cytotoxicity profiles of other nanoparticle

formulations of ICG.221, 226

Figure 3-10. (A) A cell metabolic assay showed that NPs with and without ICG

have cytotoxicity that is comparable relative to control cells. (B) Treatment of

MDA-MB-231 cells with 5 µg/ml High-PBA-HLA NP did not impact subsequent

proliferation as determined by a DNA quantification assay.

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3.0 Conclusions

The NPs developed here readily entrapped ICG through a self-assembly

process, to a maximum of approximately 10 wt%. Differences in both NP

formation and ICG loading potential were found to be dependent on the structure

of hydrophobic ligand chosen, as both PBA and 5βCA ligands had similar ICG

loading, while ODA has lower loading and also a lower requirement for molar

conjugation to HLA needed for self-assembly. These results are important, as it

shows that the choice of hydrophobic ligand plays a role in the loading of small

molecules as well as the self-assembly process, thus suggesting that choice of

hydrophobic ligand must be considered when investigating new formulations for

loading small molecules. Differently structured hydrophobic conjugates will lead

to both different NP stability, loading efficiency, and release, and thus the

quantity and type must be considered in addition to the hydrophilic section.

Optical properties of NanoICG formulations universally showed reversible

fluorescence quenching in aqueous solutions, and this fluorescence could be

reversed either by dissolution in 50/50 DMSO/H2O, where the reactivation

occurred immediately, or over time by mixing in 37 mg/ml BSA. The fluorescence

reactivation in the presence of serum proteins suggests a release from NanoICG,

and that the rate of this release is dependent on flow conditions experience by

the NPs. While fluorescence reactivation is a requirement for IGS, too quick a

release may negate the benefit of using a NP formulation. Further work is

needed to control the release of ICG in order to optimize the contrast between

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healthy and diseased tissues. A modest but significant photoprotective effect was

observed, which may indicate the potential for improved shelf life and stability in

clinical practice. NanoICG was not observed to actively target CD44(+) cancer

cells, though cells did show fluorescence. Active targeting is likely not necessary

for this type of contrast agent however, as it is the tumor bulk that requires

identification and delineation, so the intratumoral distribution of ICG may not play

a meaningful role. NanoICG was not observed to decrease metabolism or

proliferation of cancer cells in vitro, suggesting that low toxicities will also likely

be observed in vivo. Additionally, as NanoICG is intended as a surgical contrast

agent, it is unlikely that repeated exposure would be necessary.

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CHAPTER 4

TUMOR UPTAKE, BIODISTRIBUTION, AND POTENTIAL FOR IMAGE GUIDED

SURGERY OF NANO-ICG IN XENOGRAFT MOUSE TUMOR MODELS

Text and the following figures: Figure 4-1, Figure 4-2, and Figure 4-3, have been

reproduced with permission from Hill, T.K. et al., Indocyanine Green-Loaded

Nanoparticles for Image-Guided Tumor Surgery. Bioconjugate Chemistry 26(2),

2015.

1.0 Introduction

Fluorescence IGS in oncology has potential to better identify SLNs,

positive tumor margins, and local metastases. In this chapter we investigate the

potential of NanoICG formulations to identify tumor bulk and PMs in mice bearing

solid tumors. Our preliminary in vivo experiment utilized the MDA-MB-231 human

breast cancer cell line to establish tumors subcutaneously in the dorsal hip of

female nude mice. Strong fluorescence enhancement in tumors was observed

with NanoICG using a fluorescence image-guided surgery system and a whole-

animal imaging system. Tumor-muscle contrast using NanoICG was significantly

higher than ICG alone, and PMs were identified in one mouse. A second study

was performed to verify and extend the results of the preliminary study using

tissue phantoms to provide feedback on maximum potential imaging depths of

tumors in non-fluorescing tissue. This second study confirmed the improved

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signal and contrast observed in the initial study, and provided insight into deep

tissue imaging of solid tumors.

2.0 Materials and Methods

iRFP transfection of MDA-MB-231 cells

Amplification of iRFP plasmid (piRFP 31857, Addgene, Cambridge, MA.)

was performed by PCR using Platinum High Fidelity PCR SuperMix (Invitrogen

cat#12532016) and custom designed primers. Primers were designed to include

15bp of homology to the LentiX Bicistronic Expression System (puro) from

Clontech (Cat #632183) in order to perform ligation utilizing In-Fusion HD cloning

(Clontech #639645). Agarose gel electrophoresis of PCR product was resolved,

excised, and purified using Infusion spin column PCR purification kit. The LentiX

Bicistronic vector was linearized using EcoR1, resolved by agarose, excised and

gel purified. For ligation of iRFP into the lentix vector, the In-fusion Cloning was

carried out using 5x Infusion HD Enzyme mix, transformed, plated, and colonies

selected. Restriction Enzyme Digest was performed to check for orientation of

the product. Positive clones were verified and used to produce lentiviral

supernatants. To make lentivirus, the Lenti-X HTX packaging system (Clontech)

was used with Lenti-X 293T cells, and virus production was verified using Lenti-X

GoStix. MDA-MB-231 cells were transduced using 0.5ml of lentiviral supernatant

with 8 µg/ml polybrene in DMEM media for 48 hours, virus removed, and drug

selected for stable cell lines using 5 µg/ml puromycin for 5 days.

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Initial Near Infrared Fluorophore Enhanced Image-Guided Surgery

Breast tumor xenografts were introduced into 12-14 week old female

athymic nude mice (Jackson Labs; Bar Harbor, ME) by injection of 2 x 106 iRFP

MDA-MB-231 cells in 50/50 media/matrigel subcutaneously into the right hip.

When the tumors reached 500-1000 mm3, mice were injected with an

intravenous infusion via a tail vein of either ICG or High-PBA-NanoICG (10 nmol

ICG total) in 200 µl water (N = 5 mice/group). The quantities of ICG in both the

free ICG and High-PBA-NanoICG solutions were determined by dissolving a

fraction in 1:1 H2O/DMSO and acquiring the absorbance spectrum, followed by

making the appropriate dilutions to achieve 10 nmol/200 µl as determined by an

ICG standard curve. Absorbance spectra of both free ICG and High-PBA-

NanoICG were analyzed and diluted to equal absorbance values prior to

injection. Mice were euthanized 24 hours after injection of NIR fluorescent

contrast agents and the mice were imaged using a Pearl® Impulse Small Animal

Imaging System (LI-COR Biosciences; Lincoln, NE). Tumors were then removed

using a separate image-guided surgery system that has been previously

described.191, 230 In brief, skin was removed to visually inspect identifiable tumor

tissue. Next the portable fluorescence spectrometer with a fiber-coupled

handheld (SciApps; Laramie, WY) unit was used to detect NIR emission from the

tumor. The laser also served as the directed excitation source for a wide-field

NIR imaging system (SpectroPath Image-Guided Surgery System; Atlanta, GA)

that merges NIR and color channels and provides real-time video feedback for

the surgeon. Using the IGS system, tumor boundaries were first highlighted and

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then underwent a debulking procedure. Image-guided resection of enhancing

regions was iteratively performed until either no fluorescence signal was

observed at the tumor margin or until debulking was no longer possible. Mice

were then re-imaged on the LI-COR whole-animal imaging system for

comparison of iRFP fluorescence emission from the MDA-MB-231 tumor cells

(700 nm channel) with fluorescence emission from ICG (800 nm channel).

Tumor, muscle, kidney, liver, and spleen were harvested and underwent further

fluorescence imaging. Using LI-COR software, tumor to muscle contrast was

determined by generating an area of interest (AOI) around each tumor and

corresponding muscle sample. The average signal intensities of these AOIs were

then used to calculate the signal to noise and contrast to noise ratios as shown in

Equations 3.2 and 3.2. Histological analysis was performed with H&E staining.

,�.!�� � / �0� ���� = ,/� = 1��! ��00&� 0�.!�� 2�� 2�3��,456�7������

[4.1]

$ !���0� � / �0� ���� = $/� = ,/�8�9�� − ,/�:�;�< [4.2]

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Extension of In Vivo Biodistribution and Image Guided Surgery

Materials were identical to those used in the initial in vivo experiment as

outlined above. Two million MDA-MB-231 cells previously transfected with an

NIR fluorescing protein iRFP were mixed in 50/50 media/matrigel and injected

orthotopically into the inguinal mammary fat pads on both sides of 10-week old

female nude mice (5 mice, up to 10 tumors per group). Tumors were allowed to

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establish for 10-21 days prior to contrast agent administration. Presence of

tumors and approximate tumor size was confirmed by live imaging using a Pearl®

Impulse Small Animal Imaging System (LI-COR Biosciences; Lincoln, NE). Three

contrast agents groups were used: (1) free ICG, (2) High-PBA-HLA NanoICG,

and (3) High-5βCA-HLA NanoICG. NP formulations were filtered through a 0.45

µm filter to remove large aggregates. Each contained 10 nmol of ICG injected per

mouse dissolved in pure sterile water. As determined by absorbance

spectroscopy. Contrast agents were administered by tail vein injection and mice

were sacrificed either 4 or 24 hours later. Mice were the dissected and imaged

again using the Pearl® Impulse to compare tumor and tissue signals. LI-COR

software was used for image analysis to determine biodistribution, SNR, and

CNR. One mouse per contrast agent group was also examined using the IGS

equipment as outlined above.

Tissue Phantoms

Tissue phantoms, which possess optical properties similar to that of

natural tissue, were produced as described elsewhere.231, 232 Briefly, 10 w/v%

gelatin was added to a solution of 50 mM Tris-buffered saline, pH 7.4, 150 mM

NaCl, 0.1% NaN3. This solution was warmed to 45 °C under constant stirring until

gelatin was dissolved, followed by cooling to 25 °C and addition of 1 v/v%

Intralipid, and 1 w/w% bovine hemoglobin. This mixture was then pipetted into 6-

well polystyrene plates to give multiple phantoms with thickness of 6 – 2 mm.

Plates were then covered and stored at 4 °C until used.

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After tumor excision via IGS, tumors were placed underneath phantoms

and examined using both medium-low (30 W), and medium (80 W) power.

Phantoms were placed over tumors to determine the maximum depth at which

tumors could be observed under both power levels. Phantoms were also used in

the LI-COR system to determine signal loss from tumors at increasing phantom

depths up to 6 mm. Tumors were covered with phantoms made to depths

ranging from 2-6 mm in 1 mm increments, and imaged. Signal loss as a function

of thickness was measured.

Statistical Analysis

Organ biodistribution, tumor contrast, and size distribution were performed

with two-way ANOVA using multiple comparisons with Tukey’s test. Total signal

and mean signal as a function of tumor area were analyzed with simple linear

regression. All statistical analyses were done in Prism 6.0 (GraphPad Software;

La Jolla, CA) and Excel.

4.0 Results and Discussion

Initial In Vivo Investigation Using Subcutaneous Flank Tumors

iRFP-labeled MDA-MB-231 human tumor xenografts were grown

subcutaneously in the back right hip of female nude mice. When tumors were

sufficiently large, mice were injected with either ICG in water (i.e., the standard

clinical method) or the High-PBA-HLA NanoICG formulation. Mice were

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euthanized 24 hours after injection and imaged with a LI-COR Pearl Impulse

small animal imaging system and an image-guided surgery system.191, 230 Figure

4-1A shows the signal to noise ratios (SNRs) of resected tissues analyzed using

the small animal imaging system. Compared to ICG, NanoICG resulted in

substantially higher signal in tumor, although the difference was not statistically

significant (p = 0.088). The fluorescence due to ICG did not significantly differ in

other tissues (p ≥ 0.78). The combination of higher signal in tumor, but similar

background in surrounding tissue resulted in a significantly higher contrast to

noise ratio (CNR) in mice that were administered NanoICG compared to ICG

alone (p = 0.037) as shown in Figure 4-1B. The average CNR in NanoICG-

treated mice was more than twice that of mice treated with free ICG (91 vs. 40).

This is an important distinction, as it is CNR, rather than SNR, that allows for

more robust discrimination of tumor from normal tissue using IGS. The relative

biodistribution of NanoICG at 24 hours was consistent with previous results of

nanoparticle encapsulated ICG; i.e. showing the highest signal in liver and

kidneys with higher signal in the tumor compared to surrounding tissues.222, 226,

233-235 The majority of ICG accumulated in the liver for both NanoICG and free

ICG formulations, which is consistent with ICG clearance.236, 237 While no

significant difference was observed between the SNR of similar tissues,

NanoICG exhibited lower kidney and muscle accumulation, and higher liver and

spleen accumulation than free ICG. Representative NIR emission images from

ICG and NanoICG are shown in Figure 4-2. The comparable overall SNR from

ICG and NanoICG are indicative of some degree of ICG dissociation from the

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NPs. The higher liver and spleen signal from NanoICG may indicate some

interaction with resident macrophage. The statistically significant CNR values

between ICG and NanoICG in tumor indicate that NanoICG has distinctly

different biodistribution compared to free ICG. These results are likely

independent of NanoICG dose. A recent report demonstrates that ICG that was

directly conjugated to PEG-grafted HLA, where ICG served as the hydrophobic

ligand, resulted in tumor signal, both fluorescence and photoacoustic, that was

more than double that of femur.238 However, the dose of ICG used in this study,

50 nmol per mouse, was 5 times greater than the dose used in our study.

Figure 4-1. (A) Biodistribution of ICG 24 hours after injection as measured by

SNR. Liver accumulated the majority of ICG from both formulations, followed by

kidney. NanoICG and ICG SNR were not found to be significantly different in the

tested tissues, although the NanoICG signal was higher in tumor tissue (p = .088;

N = 5 mice/group). (B) The contrast-to-noise ratio (CNR) between tumor and

surrounding muscle was significantly higher in NanoICG-treated tumors,

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suggesting that the NanoICG formulation improved the potential for

distinguishing between tumor and normal tissue. *p ≤ 0.05 was considered

significant.

Figure 4-2. Representative NIR imaging of dissected organs from mice treated

with free ICG (A) or NanoICG (B). Results show higher uptake in the tumor (t),

liver (li), and spleen (s) of NanoICG treated mice. Intensities of both images have

been set to the same scale. Order of organs displayed from left to right: tumor (t),

muscle (m), heart (h), lung (lu), pancreas (p), kidney (k), liver (li), spleen (s).

Image Guided Surgery

Small animal florescence imaging, provided by LI-COR Pearl Impulse

system, indicated iRFP fluorescence (700 nm channel; false-colored red) that

was consistent with the location of the iRFP-labeled MDA-MB-231 cells; a

representative example is shown in Figure 4-3A. Using the separate IGS

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system,191, 230 directed laser excitation (785 nm) of the tumor produced strong

fluorescence enhancement due to the presence of ICG (Figure 4-3B; false-

colored cyan), which corresponded to the boundaries of iRFP-labeled tumor cells

observed in Figure 4-3A. Laser excitation of surrounding normal skeletal muscle

showed no fluorescent signal based on a predetermined threshold (Figure 4-

3C).191 Subsequently, the tumor was debulked under IGS using fluorescence

enhancement from NanoICG. Figure 4-3D shows the presence of ICG in the

resected tumor mass. A region of tissue that fluorescently enhanced at the

tumor/normal tissue interface during IGS could not be excised because removal

was restricted by the presence of bone (Figure 4-3E). However, subsequent 700

nm imaging (in the whole animal imaging system) and histological analysis after

animal necropsy revealed that this fluorescence-enhancing region was due to

tumor infiltration into normal tissue (Figure 4-3E&F). Further investigations are

planned to determine NanoICG’s ability to enhance specifically at the tumor

margin. Analysis of the debulked tissue and mouse carcass with whole animal

fluorescence imaging at 700 nm to detect iRFP-labeled MDA-MB-231 cells

(shown in Figure 4-3F) confirmed the fluorescence enhancement detected in

tumor by IGS.

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Figure 4-3. In vivo analysis of NanoICG tumor accumulation. (A) Preoperative

imaging of iRFP shows the location of MDA-MB-231 breast tumor xenograft; the

signal in the abdomen is due to rodent chow in the intestinal tract. (B) Image-

guided surgery (left) and H&E histological staining (right) confirm high fluorescent

signal in the bulk of the tumor, (C) while only low fluorescent signal is observed in

adjacent normal tissue. (D) The resected tumor exhibits fluorescent signal;

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presence of tumor was confirmed at histology. Tumor margins were then

inspected for fluorescent enhancement to confirm tumor removal. (E)

Fluorescence was detected at the tumor margin, suggesting remaining tumor

tissue. (F) Positive margins were confirmed by observing iRFP signal at the

location indicated by the presence of NanoICG.

Further In Vivo Investigation with Orthotopic Breast Tumors and an Additional

Contrast Agent

This study differs from the previous section in that tumors were injected

into the inguinal mammary fat pads of female nude mice, with one tumor on each

side of each mouse. Cells used were again MDA-MB-231 breast cancer cells

expressing iRFP protein. Both 4 and 24 hours timepoints were examined, and

excised tumors were further analyzed using tissue-mimicking phantoms.

Mice treated with NanoICG showed lower SNR compared to free ICG at 4

hours, and higher SNR compared to those treated with free ICG at 24 hours, as

shown in Figure 4-4A&B. Total ICG signal was higher at 4 hours for all organs

and all contrast agents, suggesting that a significant amount of metabolism and

excretion occurs between 4 and 24 hours. Free ICG shows high levels of

fluorescence in the kidneys at 4 hours, which is consistent with the clearance of

small molecules. SNRs of NanoICG formulations are significantly lower in the

kidney but not significantly different in the liver at 4 hours, which is consistent

with clearance of NPs. Biodistribution at 24 hours was also consistent with that

expected of NP materials, with higher accumulation in the liver and spleen, and

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approximately equal distribution in other organs. CNRs at 4 hours were highly

variable (Figure 4-4C), with some CNRs from individual mice being negative

(higher signal in muscle). However, at 24 hours High-PBA-HLA NanoICG [95%

CI: 15.4-2.6] and High-5βCA-HLA NanoICG [95% CI: 12.62-0.65] showed higher

tumor to muscle CNR than ICG (Figure 4-4D). These results confirm the

previously observed in vivo results that NanoICG formulations increase ICG

accumulation within xenograft tumors and improve differentiation between

diseased and healthy tissue at 24 hours. Interestingly, the 4 hour data gives

insight into the metabolism and clearance of these contrast agents, and further

suggest that NanoICG retains a NP structure in vivo. The kidney and liver signals

are consistent with NP clearance at both 4 and 24 hours for NanoICG.

Additionally, total ICG administered was the same across all contrast agent

groups, but the fluorescence signal is lower in NanoICG mice in all organs at 4

hours. It is thus possible that the fluorescence signal is being quenched due to

tight packing of ICG within the NPs. Tumors were similarly sized across contrast

agent groups and thus the high tumor SNR and CNR likely result from improved

accumulation due to the NP formulation of ICG. While the observed loss of ICG

from NanoICG to serum proteins previously observed in vitro is likely to be

occurring, it appears that NanoICG still allows for improved tumor accumulation.

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Figure 4-4. NanoICG formulations show lower total signal in tumors at 4 hours

relative to ICG (A), but higher signal relative to ICG at 24 hours (B). At four hours

the ICG signal is higher in most tissues compared to NanoICG, particularly the

kidney where small molecules are cleared (A). Contrast between tumor and

muscle was highly variable at 4 hours, and no formulation is significantly different

from another (C). The biodistribution of NanoICG at 24 hours reflects that

expected of NP formulations, with higher signal in the liver and spleen and similar

distributions in other tissues (B). The total signal present at 24 hours was less

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than at 4 hours in all tissues, suggesting that a high amount of metabolism or

clearance has occurred to reduce to total amount of ICG present. (D) Contrast

between tumors and muscle at 24 hours showed that uptake into the tumor was

significantly higher for NanoICG formulations.

Analysis of the size distribution of tumors in each treatment group is

shown for 4 hours (Figure 4-5A) and 24 hours (Figure 4-5B). Tumors analyzed

at 4 hours deviated slightly between groups, with the ICG group (9.45 ± 4.79

mm2) being slightly larger than the High-5βCA-NanoICG group (5.56 ± 1.60

mm2). At 24 hours, all groups showed similar tumor sizes. Total signal in the

tumors were proportional to tumor cross-sectional area for both 4 hours (Figure

4-5C) and 24 hours (Figure 4-5D), with 95% CI for these values as [ICG: 3125-

9660 (4 hrs), 984.7-1490 (24 hrs)], [High-PBA-NanoICG: -1476-5135 (4 hrs),

603.2-2772 (24 hrs)], and [High-5βCA-NanoICG: 1130-3633 (4 hrs), 1669-4557

(24 hrs)]. Slopes from Figure 4-5C&D are in units of (total pixel intensity)/mm2.

However, mean signal per unit area, shown in Figure 4-5E (4 hours) and Figure

4-5F (24 hours), was not found to give a trend for increasing volumetric signal

intensity with change in tumor size, as no slopes were found to be significantly

different from zero. In other words, the signal intensity from equal tumor areas is

not dependent on the size of the tumor (E&F), but the total signal intensity from a

tumor is dependent on tumor size (C&D). This indicates that contrast agent

accumulation is approximately the same in a given volume of tumor, regardless

of the size of that tumor, and thus tumor detection across the range tested is

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limited by instrument sensitivity and contrast, rather than tumor size. As can be

seen in Figure 4-5, even very small tumors with cross sections less than 1 mm2

were detectable after resection, and thus could potentially be visualized in vivo.

Figure 4-5. (A) The average size of tumors in each contrast agent group at 4

hours was between 5-10 mm2, and ICG tumors were slightly larger than High-

5βCA-NanoICG tumors. No difference in tumor size was observed at 24 hours

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(B). (C-D) Total signal present in a tumor is dependent on tumor size, with larger

tumors having more total signal. However, the average signal intensity per unit

area does not correlate with tumor size (E-F).

Tumors were examined in situ using the IGS system by first resecting

overlying skin and examining the fluorescent signal at different locations of the

mouse ventral surface. Images were captured before and after tumor removal.

As is seen in Figure 4-6, the signal on the surface at the tumor location is strong

(Figure 4-6A). Most tumors were clearly visible to the naked eye and the majority

of the tumor bulk could be resected without the aid of the IGS system. Isolated

tumors also showed strong fluorescent signal (Figure 4-6B). However, in most

cases the surgical margins could not be examined using the IGS system due to

strong underlying fluorescent signal from the visceral organs (Figure 4-6C). As

seen in Figure 4-4, the fluorescent signal from the kidneys, liver, and spleen are

very high, and the intestines appeared fluorescent as well. Thus, due to the

hepatobiliary and renal accumulation, surgical margins are generally not

discernable using this tumor model in mice. In the previous study (Figure 4-3),

the tumor location was in the back right hip on the dorsal surface and this

location afforded protection of the signal from the visceral organs, allowing for

effective detection of PMs. Future animal models will have to take this into

account, to ensure that tumors are located in clinically relevant tissue while

ensuring there is a sufficient distance from liver, kidney, and spleen to prevent

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background signal from these organs. Thus, a larger animal model may be

necessary.

Figure 4-6. (A) Administration of High-PBA-HLA NanoICG showed strong

fluorescent signal in the tumor region prior to excision. (B) Surgical removal of

the tumor shows a strong fluorescent signal when separated from the body,

however the background signal from the internal organs remained high after

excision (C). Laser is highlighting the previous position of the tumor, however no

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tumor is present. Excess signal results from high levels of ICG in visceral organs

in the background, indicating that this tumor model is inadequate for IGS.

Analysis with Tissue Mimicking Phantoms

Detection of local metastases is necessary for the complete removal of

diseased tissue during surgery. However, these local metastatic sites will not

always be located at the tumor surface, making detection at depth a critical

feature of IGS. Tissue mimicking phantoms were used to determine the

theoretical maximum detection depth of ex vivo tumors using ICG and NanoICG

contrast agents. Signal loss of xenograft tumors was measured from 0-6 mm

below phantoms. As shown in Figure 4-7, the average signal decreases with

increasing tissue depth. Tumors were still visible up to 6 mm beneath tissue

phantoms, and the 95% CIs for predicted depths of zero signal are 6.8 – 8.8 mm

(ICG), 6.7 – 9.8 mm (High-PBA-HLA), and 6.7 – 10.7 mm (High-5βCA-HLA).

Representative tumors at these depths are shown in Figure 4-7C. These

phantoms did not contain any ICG, and therefore represent idealized tissues in

which contrast agent accumulation does not occur, or from which it has cleared

completely. In a real tissue, some level of contrast agent will be present, and this

will likely decrease the sensitivity to tumors found at depth. Nonetheless, these

results indicate that NIR fluorescence imaging using NanoICG provides sufficient

signal to identify tumors below the tissue surface and may thus improve the

identification of local metastases or SLNs in larger animal models or humans.

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Figure 4-7. Tumor signal decreases as a function of depth beneath tissue-

mimicking phantoms at both 4 hours (A) and 24 hours (B). Relative SNR. (C)

Representative images from the 24 hour time point of tumors beneath phantoms

ranging from 6-0 mm, showing an increase in scattering and decrease in photon

penetration with increasing phantom thickness.

The image-guided tumor surgery study reported here, removal of a breast

tumor xenograft in mice with image-guidance, demonstrates the potential of

NanoICG to depict tumor margins in the operating room. The colocalization of

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ICG signal and iRFP-labeled MDA-MB-231 tumor cells establishes that ICG

delivery to tumors using NanoICG was successful and indicated the tumor

boundaries. The strong contrast enhancement in the tumor in both studies

showed that more ICG was delivered to tumors by NPs with lower background

signal in surrounding tissue, which could provide meaningful data to surgeons in

the operating room. In combination, these results suggest that use of NanoICG

could potentially serve as a contrast agent for IGS.

Ultimately, one could envision using NanoICG with image-guided surgery

to determine surgical margins. However, determining the tumor margin is

complex. Currently, a positive margin is determined by the presence of

neoplastic cells at the edge of the excised tumor. These can be detected by

intraoperative pathology and definitively by IHC after the surgery. There is no

method currently available to detect tumor cells remaining in the surgical cavity.

Using xenograft tumor models in mice, while useful to evaluate overall SNR and

tumor contrast, has physical and biological limitations. With the resolution of

optical imaging methodologies being approximately 0.1 x 0.1 mm,230, 239 this

gives the level of contrast agent distribution and signal necessary for effective

surgical removal. Further investigation will be required to determine how the

intratumoral biodistributions affects the surgeon’s ability to detect surgical

margins by image-guided surgery.

The mechanism of ICG release to transition from a quenched to an

unquenched state is likely the result of release of ICG from NPs to serum

proteins and lipids or degradation via hyaluronidases. The comparable overall

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biodistribution of NanoICG to ICG in non-tumor tissues at 24 hours indicates that

ICG exchanges from NanoICG to serum proteins to some extent. Intratumoral

degradation by hyaluronidases provides an additional mechanism for tumor-

specific fluorescence activation, but differentiating these effects will require

additional investigation. The high kidney signal of free ICG at 4 hours suggests

that there is a high level of renal clearance immediately after administration. As

NanoICG formulations do not appear to be cleared as rapidly by this mechanism,

this suggests that NanoICG-treated mice may show higher tumor SNRs because

more ICG remains in circulation. The fluorescent signal of free ICG-treated mice

was higher on average in all organs at 4 hours. We also observe similar or

greater levels of fluorescence in all tissues from animals treated with NanoICG

formulations at 24 hours. As the same quantity of ICG was injected in all groups,

this suggests that the NanoICG formulations are exhibiting a level of

fluorescence quenching at 4 hours, which is causing the reduced signal.

Combined, the high signal of free ICG in all organs at 4 hours, equal or higher

signal of NanoICG at 24 hours, and fluorescence quenching effect observed in

vitro, suggest that NanoICG remains intact during circulation. This results in

fluorescence quenching, and an increased circulation time, resulting in higher

tumor CNR than ICG at 24 hours.

Analysis with tissue mimicking phantoms provided signal up to 6 mm deep

and predicted maximum detection depths of approximately 8-9 mm. This

represents an ideal situation in which the surrounding tissue provides minimal

contrast. Studies using similar phantoms detected ICG-loaded agarose

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inclusions up to 15 mm deep, with signal declining rapidly between 7-11 mm.232

Other studies have found that tissue penetration is dependent on tissue type,

with fat having the higher penetration than liver or lung, and a maximum ICG

detection depth of approximately 5 mm.191 The potential maximum detection

depth of tumors underlying healthy tissue is likely to be between 5-10 mm.191, 230,

239 However, a number of factors will influence this depth. Volume and fluid

distribution within the tumor will strongly affect the level of contrast agent uptake

and thus total signal and imaging depth.240 The number of cells in a tumor may

influence fluorescence signal indirectly by affecting tumor size and vascularity,

and therefore total contrast agent uptake.

4.0 Conclusions

The potential to use IGS in treatment of operable tumors is clear:

improved detection of tumors and their boundaries could minimize recurrent

disease. In this study NPs derived from HLA were used to deliver the NIR

fluorophore ICG in an attempt to improve contrast enhancement. Tumor contrast

was observed in both studies, providing strong evidence for a NP-mediated

delivery of ICG. However, it has become clear that the choice of animal model

and tumor location are of high importance when investigating the efficacy of

contrast agents with IGS. Ultimately, the efficacy of NanoICG will be depend on

whether the increased contrast enhancement in IGS results in decreased tumor

recurrence, and further studies in larger animal models are required to test this.

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CHAPTER 5

APPLICATION OF HYALURONIC ACID DERIVED NANOPARTICLES TO

DRUG DELIVERY

This work was performed in conjunction with the Steven J. Kridel and W. Todd

Lowther labs. Empty and drug loaded NPs were provided by our lab for the

following assays. Jill Clodfelter performed the direct FASN inhibition assay

(Figure 5-2A), Frances B. Wheeler performed the 14C-acetate uptake assays

(Figure 5-2B and 5-4), and Amanda L. Davis performed the Seahorse metabolic

assays (Figure 5-7). This work is currently in preparation for submission to

Molecular Pharmaceutics.

1.0 Introduction

ORL is an effective, irreversible inhibitor of FASN. However, it is highly

hydrophobic and does not distribute well when administered orally. Thus, a

method is needed to improve its distribution and activity when administered

intravenously. In order to improve delivery of active ORL to tumors we have

developed a novel ORL formulation, termed Nano-ORL, in which ORL is loaded

into the hydrophobic regions of self-assembled polymeric NPs derived from

HLA.45, 241 In addition to being a natural, biodegradable polymer, HLA may also

serve to improve uptake into tumor cells through interaction with the cell surface

receptor CD44, which is overexpressed in a number of tumor types.242-245

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Increased activity of hyaluronidases found in breast and prostate cancers may

also serve to release therapeutic payloads upon delivery to tumors.46, 47 In this

chapter we modified HLA polymers with a hydrophobic moiety, PBA, to drive self-

assembly and load ORL into Nano-ORL. Nano-ORL was analyzed for physical

properties and ORL loading capability. FASN was confirmed as a target molecule

for Nano-ORL using direct molecular inhibition and decreased lipid synthesis was

confirmed by measurement of 14C-acetate incorporation. Nano-ORL was

demonstrated to be more toxic than ORL to cancer cell lines over a 48 hour

period. This increase in toxicity is shown to result from an increased stability of

the Nano-ORL formulation over free ORL when both are dissolved in aqueous

solution. Finally, Seahorse XF24 analysis demonstrated decreased O2

consumption and mitochondrial metabolism after treatment with Nano-ORL.

2.0 Materials and Methods

ORL was obtained from 120 mg Xenical capsules (Roche; Basel, CH) or

in powder form (Alfa Aesar; Ward Hill, MA). Sodium hyaluronate was purchased

from Lifecore Biomedical (Chaska MN). 1-Pyrenebutyric acid, 1,3-

diaminopropane, N-hydroxy succinimide, and 1-ethyl-3-(3-

dimethylaminopropyl)carbodiimide (EDC) were obtained from Sigma-Aldrich (St.

Louis, MO). Unless otherwise noted, all water was obtained from a Barnstead

NANOpure Diamond (Thermo Scientific; Waltham, MA) system producing 18.2

MΩcm water. Methanol, N, N dimethylformamide (DMF), 96-well tissue culture

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plates (Falcon), were purchased from Fisher Scientific (Pittsburgh, PA). Ethanol

was purchased from the Warner-Graham Company (Cockeysville, MD).

Penicillin/streptomycin and other media reagents (Gibco) were purchased from

the Cell and Viral Vector Core Laboratory of the Comprehensive Cancer Center

of Wake Forest School of Medicine. Cell lines were obtained from American Type

Culture Collection (Manassas, VA) and were grown in RPMI-1640 or EMEM with

10% fetal bovine serum, 1% penicillin/streptomycin.

Drug Loading and Quantification

ORL was isolated from Xenical capsules by mixing capsule contents into

10 ml ethanol or methanol, followed by vortexing and centrifugation at 1500 RPM

for 5 minutes. Solution was then separated from the precipitated filler material,

followed by a second separation and centrifugation. Stock 12 mg/ml (24.2 mM)

ORL solution was then aliquoted and stored at -20 °C. Stock solution was also

prepared from powdered ORL (Alfa Aesar) by dissolution into ethanol or

methanol to a concentration of 12 mg/ml followed by storage at -20 °C. ORL was

loaded into NPs by dissolution of 18.0 mg HLA into 10 ml H2O, followed by

addition of 10 ml ethanol. ORL (2.0 mg, 4.0 µmol, 20wt% loading) was then

added and the solution was dialyzed against pure water for 24 hours (MWCO =

3500 Da, Spectrum Labs). Material was then filtered through PD-10 columns (GE

Lifesciences; Pittsburgh, PA) to remove free ORL, followed by lyophilization to

produce a low density, white, fibrous material, and was stored at -20 °C. This

material is termed Nano-ORL.

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ORL loading efficiency was determined by extraction from Nano-ORL

followed by HPLC quantification. Extraction of ORL was performed following the

protocol for extraction of ORL from human plasma as described in the

literature.246 A standard curve of ORL extraction from NPs was performed by

spiking solutions of empty NPs with known quantities of ORL from stock solution

and performing the following extraction protocol. Empty NPs were dispersed into

pure H2O to a concentration of 1.0, 0.5, or 0.25 mg/ml. Stock ORL was then

added to the empty NP solutions to a concentration of 0.20, 0.10, or 0.05. mg/ml.

1.0 ml aliquots of these solutions were then mixed with 1.0 ml acetonitrile, to

which 5 ml n-hexane was added. This solution was then stirred for 30 minutes, at

which time the hexane layer was removed and evaporated under vacuum.

Extracted ORL was dissolved in 100% HPLC grade MeOH and run on a

Beckman Ultrasphere UDS 4.6 x 250 mm column with 5 µm particle size using a

mobile phase of 82.5:17.5 methanol:acetonitrile-.01% trifluoroacetic acid with a

Waters 510 pump, 717+ autosampler, and 2998 PDA UV/Vis detector.247, 248

Separation was isocratic and ORL was measured at 200-205 nm. Each ORL

concentration was performed in quadruplicate. ORL content in Nano-ORL was

then measured by performing these extraction methods and comparing to the

standard curve. Loading efficiency of Nano-ORL was then determined by re-

suspension of Nano-ORL into pure H2O at a concentration of 0.50 mg/ml and

extracted and analyzed in quadruplicate as described above. Extracted values

were then analyzed using the standard curve.

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Physical Characterization

In addition to 20wt% ORL loading, 5wt% and 10wt% loading Nano-ORL

formulations were also synthesized using identical conditions in order to test the

effect of ORL loading on NP size. 0, 5, 10, and 20wt% ORL formulations were

dissolved in pure H2O to a concentration of 1.0 mg/ml. Hydrodynamic diameter

was then determined using a ZetaPlus system with onboard dynamic light

scattering (DLS) analyzer (Brookhaven Instruments Corporation; Holtsville, NY).

FASN Inhibition

The C-terminal thioesterase domain of FASN (FASN-TE, residues 2200-

2510) was expressed and purified as previously reported.249 The inhibition assay

using 4-methylumbelliferyl heptanoate (MUH) as the substrate was slightly

modified from what was previously reported.250, 251 The 100 μl reactions

contained 250 nM FASN-TE, 100 mM Tris pH 7.4, 50 mM NaCl, 1 mM EDTA,

120 μM MUH, 1% DMSO, and Orlistat 0.1-10 μM. Orlistat was preincubated with

FASN-TE for 30 min at 37 °C prior to starting the reaction with MUH. The

samples within a 96-well plate were read, at 30 s intervals for 30 min, on a Tecan

Safire2 instrument (excitation, 350 nm; emission, 450 nm).

Inhibition of Lipid Synthesis

For analysis of the inhibition of lipid synthesis by Nano-ORL, PC3 cells

were seeded in two 24-well plates, 7 x 104 cells per well, and treated two days

later with inhibitors or vehicle controls, in quadruplicate for 17-18 hours. [2-C14]

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acetate (0.037MBq, 1 µCi; PerkinElmer, Boston, MA) was added to wells in one

plate for two hours. The cells were trypsinized, washed, and lysed in hypotonic

buffer (20 mM Tris-HCl, pH 7.5, 1mM EDTA, 1mM DTT). Lipids were extracted in

chloroform:methanol (2:1). The organic fraction was washed twice with PBS,

then transferred to vials for scintillation counting (Beckman Coulter LS 6500).

Protein concentration was determined by the Lowry method (Bio-Rad, Hercules,

CA) in cells treated in the duplicate plate.

Cytotoxicity

PC3, MDA-MB-231, U87mg, or RKO cell lines were seeded separately

into 96-well plates at concentrations of 2000 cells/well and allowed to adhere

overnight. Empty NPs and Nano-ORL were resuspended in culture media

(EMEM with 10% FBS and 1% P/S), and stock ORL was diluted into normal

media from ethanol. Cells were then treated with either normal media, empty

NPs (0.062 mg/ml), ORL (0.0124 mg/ml, 25 µM), or Nano-ORL (0.062 mg/ml,

theoretical [ORL] = 25 µM, actual [ORL] = 24 µM due to loading efficiency) and

allowed to incubate at 37 °C for 48 hours. After 48 h incubation, cells were

analyzed by CCK-8 assay (Dojindo, Japan) and results were normalized to the

standard media group.

Similar methods were used to study the effect of pre-incubation on ORL

and Nano-ORL. PC3, MDA-MB-231, U87mg, or RKO cell lines were seeded

separately into 96-well plates at concentrations of 2000 cells/well and allowed to

adhere overnight. ORL and Nano-ORL were first dispersed in serum-free media

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at concentrations of 0.124 mg/ml (250 µM) and 0.62 mg/ml, respectively. These

solutions were then incubated for 24 hours at 37 °C. ORL and Nano-ORL

solutions were then diluted to 0.0124 mg/ml (25 µM) and 0.062 mg/ml,

respectively, in serum-containing media. Empty NPs were also treated in a

manner identical to Nano-ORL. Non-incubated ORL and Nano-ORL solutions

were also formed at identical concentrations to pre-incubated ORL and Nano-

ORL. All non-incubated solutions, including standard media, were diluted to the

same fetal bovine serum and penicillin/streptomycin concentrations as pre-

incubated solutions. Solutions were then applied to cell lines and allowed to

incubate for 24 hours. At 24 h, solutions were re-applied (both pre-incubated and

non-incubated) in order to maintain concentrations of free ORL and Nano-ORL.

CCK-8 assay was performed at 48 hours and all groups were normalized to the

standard media group.

Chemical Stability

Nano-ORL (0.5 mg/ml) and ORL (0.1 mg/ml) were separately dispersed

into PBS and incubated at room temperature for 96 hours. At 96 hours 1 ml

aliquots of each were removed and Orlistat was extracted as previously

described. Samples were then dried under argon and redissolved in 82.5:17.5

methanol:acetonitrile with 0.1% trifluoroacetic acid and infused into a Quantum

Discovery Max (Thermo Scientific) quadrupole mass spectrometer at 10 µl/min

for m/z 450-600 Da.

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Mitochondrial Respiration Assays

All cellular oxygen consumption rates (OCR) were measured using the

XF24 Extracellular Flux Analyzer (Seahorse Bioscience; Massachusetts, United

States) per manufacturer’s instructions. LnCap cells were plated on 22.4 μg/ml

Cell-Tak (Corning; Corning, New York, United States) at 40,000 cells/well in

RPMI-1640 with 10% FBS/1% PS. MDA-MB-231 cells were plated at 40,000

cells/well in RPMI-1640 10% FBS/1% PS. Cells were treated with identical

media containing either vehicle or test compounds for 16 hours. Before OCR

measurements were taken, cells were washed with Seahorse assay media

supplemented with fresh sodium pyruvate and glucose per published Seahorse

protocol and incubated at 37 °C without CO2 for 1 hour. After equilibration, three

3-minute measurements were recorded. Oligomycin (1uM), FCCP (0.5uM), and

Rotenone/Antimycin A (1uM each) were injected into each well sequentially with

three 3-minute measurements after each injection. The following metrics were

used in accordance with published Seahorse protocols and previous

publications252 to analyze results:

+�0�� ��02����� ! = 3�' @�0�� >��0&��>�!� [5.1]

�($ -�������� � ��02 !0� = >�3�>&> ���� ����� A$$B �!C��� [5.2]

-(B $ &2��� ��02 !0� = >�!�>&> ���� ����� D��. >E��! �!C���� ! [5.3]

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,2��� ��02���� � $�2����E = �($ -�������� � ��02 !0�+�0�� ��02����� !

[5.4]

$ &2��!. �������!�E = 1 − -(B $ &2��� ��02 !0�+�0�� ��02����� !

[5.5]

After completion of OCR measurements, cells from each treatment condition

were pooled and counted via trypan blue exclusion. Total live cells counts were

used to calculate the average number of live cells per well for each treatment

group. The average number of live cells per well per treatment was then used to

normalize OCR readings to live cell number.

Statistical Analysis

Extracted stock ORL measured by HPLC was plotted and analyzed using

linear regression to form a standard curve. Extracted Nano-ORL was quantified

using this standard curve. Average hydrodynamic diameters of Nano-ORL with

different loading wt% ORL were plotted and analyzed using linear regression.

FASN inhibition, 14C-acetate incorporation, cytotoxicity, and mitochondrial

respiration assays were analyzed separately using two-way ANOVA with multiple

comparisons using Tukey’s test.

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3.0 Results and Discussion

Drug Loading and Physical Characterization

ORL was loaded into NPs by dissolution of ORL and empty NPs into

50:50 H2O:EtOH followed by dialysis into pure H2O, PD-10 filtration, and

lyophilization to produce Nano-ORL. A standard curve of ORL extraction from

NPs was created by spiking empty NPs with known quantities of ORL followed by

extraction and quantification. Figure 5-1A shows the standard curve and

extracted Nano-ORL values. An R2 = .98 was achieved over the range from 0.05

mg to 0.20 mg/ml [ORL] for the standard curve. Nano-ORL was then re-

suspended in pure H2O to a concentration of 0.50 mg/ml, (theoretical [ORL] = 0.1

mg/ml) extracted and compared to the standard curve. Analysis of the extracted

Nano-ORL gave a loaded wt% of 19.3wt% ± 0.4wt%, corresponding to a 96.7% ±

2.4% loading efficiency. Thus, nearly all of the ORL loaded (20wt%) is retained

(19.3wt%) through the loading process and lyophilization.

The effect of ORL loading on NP size was investigated by loading different

levels of ORL into NPs. NPs were loaded with 0, 5, 10, and 20wt% ORL using

identical methods. These Nano-ORL formulations were then re-suspended in

H2O and hydrodynamic diameters were acquired using dynamic light scattering.

Figure 5-1B shows the linear effect on effective diameter of ORL loading, with an

R2 = .99 indicating that ORL loading has a direct influence on the size of Nano-

ORL. Hydrodynamic diameters range from approximately 290-580 nm. As the

Nano-ORL formulation with 20wt% loading has approximately 97% loading

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efficiency, and formulations with lower ORL loading respond in a nearly perfect

linear fashion to ORL, it is very likely that these lower ORL content Nano-ORL

formulations have approximately the same loading efficiency.

Figure 5-1. (A) Extraction of ORL from empty NPs spiked with stock ORL

resulted in a standard curve that is linear across the range of 0.05 to 0.20 mg/ml

(R2 = 0.98). ORL extracted from Nano-ORL was found to be at 96.7% ± 2.4% of

the theoretical value, giving Nano-ORL a composition of approximately 19.3wt%

ORL and 80.7wt% PBA-HLA. (B) Effective diameters, as determined by dynamic

light scattering, were found to increase with increasing loading amounts of ORL.

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Empty NPs were found to be in the range of 290 nm, increasing linearly up to

580 nm with approximately 20wt% ORL. This linear increase in diameter

suggests that Nano-ORL size can be controlled using ORL content, and may

allow us to optimize NP diameter for delivery to tumors in future studies.

Inhibition of FASN and Lipid Synthesis

Results in Figure 5-2A indicate that stock 10 µM extracted stock ORL and

extracted Nano-ORL both inhibit approximately 93% of FASN activity. At 1 µM

extracted stock ORL shows approximately 31% inhibition, and extracted Nano-

ORL shows 36% inhibition. At 0.1 µM extracted stock ORL shows 0% inhibition,

and extracted Nano-ORL shows 7% inhibition. Extracted stock ORL and

extracted Nano-ORL show similar FASN inhibtion over all concentrations

measured, indicating that the Nano-ORL formulation is just as effective in

inhibiting FASN activity as pure ORL. These results suggest that the process of

loading and storing ORL in the Nano-ORL formulation is not causing degradation

or resulting in lower ORL FASN inhibition.

Inhibition of lipid synthesis by FASN inhibition was then analyzed using

14C-acetate uptake analysis. Acetate is metabolized upstream of FASN and

eventually incorporated into the major FASN product palmitate, which is further

metabolized into other lipids. Figure 5-2B shows measurement of this FASN

activity in cells by treatment of cells with either empty NPs, free ORL, or Nano-

ORL, followed by addition of 14C-acetate, which is incorporated into lipids.

Results indicate that lipid synthesis is reduced for cells treated with either free

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ORL or Nano-ORL (ORL = 38%, Nano-ORL = 49% of the control). Neither free

ORL or Nano-ORL were found to be significantly different from one another [95%

CI: (-)5476 – 13862]. Empty NP vehicle was not found to be significantly different

from control media [95% CI: (-)9192 – 10145], suggesting that the observed

effect of Nano-ORL results solely from ORL incorporated into the NPs. All other

groups were found to be significantly different from one another at α = 0.05.

Figure 5-2. (A) FASN was directly inhibited using ORL extracted from Nano-ORL

or stock ORL that underwent the extraction protocol. The FASN inhibition of ORL

extracted from Nano-ORL was similar to extracted stock ORL, indicating that

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ORL activity is retained through NP loading and lyophilization. (B) Nano-ORL

was tested for its ability to inhibit lipid synthesis in living cells. 14C-acetate

incorporation in lipids was measured when cells were exposed to empty NPs,

Nano-ORL, or ORL. Cells treated with empty NPs did not show a decrease in

lipid synthesis, while both Nano-ORL and ORL inhibited lipid synthesis to a

similar degree.

Cytotoxicity of Nano-ORL

Cytotoxicity of Nano-ORL was tested against human cancer cell lines PC3

(prostate), MDA-MB-23 (breast), U87mg (malignant glioma), and RKO

(colorectal) using CCK-8 assay. Cells were exposed to 25 µM ORL, 0.062 mg/ml

Nano-ORL (25 µM ORL theoretical concentration), 0.062 mg/ml empty NP, or

normal media and allowed to incubate for 48 hours. As seen in Figure 5-3A-D

both ORL and Nano-ORL show significant levels of toxicity, with relative

viabilities ranging from 40-80% for ORL, and 21-57% for Nano-ORL. Nano-ORL

was significantly more toxic than ORL in all cell lines tested (p < 0.0001). It is

unlikely that this increase in toxicity is due to a toxic effect of the NP scaffold, as

empty NPs show relative viabilities similar to normal media. Rather, it is possible

that the increase in cytotoxicity of Nano-ORL is due to the increased solubility or

stability of ORL due to its localization within NPs. ORL is very hydrophobic, and it

was thought that prolonged exposure to cell growth media, even in the presence

of fetal bovine serum, would potentially cause ORL to aggregate or hydrolyze

and thus become less cytotoxic. To test this, we pre-incubated ORL, Nano-ORL,

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and empty NPs for 24 hours at 37 °C prior to application to cells (designated with

PI superscript). Media was re-applied at 24 hours (again after 24 hours pre-

incubation) to ensure a consistent level of pre-incubated drugs and materials,

and plates were tested with CCK-8 assay. In Figure 5E-H we again observed

that the Nano-ORL formulation is significantly more cytotoxic than the ORL

formulation (p ≤ 0.0001 for MDA-MB-231, p ≤ 0.01 for PC and U87mg). ORL and

Nano-ORL were equally cytotoxic in RKO cells. As can be seen in the ORLPI

groups however, ORL becomes much less cytotoxic after 24 hour pre-incubation

in cell growth media, with relative viability of ORLPI increasing by 20-50% of the

control group over ORL (p ≤ 0.0001 for all cell lines). In comparison, there was

no significant difference between Nano-ORL and the pre-incubated Nano-ORLPI

groups in any of the cell lines. No cytotoxicity was observed to result from empty

NPs. These results confirm that the Nano-ORL formulation results in significantly

higher stability of ORL and thus may improve chemotherapeutic efficacy in vivo.

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Figure 5-3. 48 hour cytotoxicity analysis shows that the Nano-ORL formulation results in significantly lower relative

viability of cancer cell lines PC3 (A), MDA-MB-231 (B), U87mg (C), and RKO (D) compared with free ORL. This result is

not due to a toxic effect of PBA-HLA, as empty NPs exhibited no increase in cytotoxicity. Cells were then treated with ORL

and Nano-ORL that had been pre-incubated for 24 hours prior cell exposure. It was observed that ORL was significantly

less toxic after pre-incubation, while Nano-ORL did not lose efficacy, and both pre-incubated and non-incubated Nano-

ORL exhibited higher toxicities than free ORL and pre-incubated ORL in PC3 (E), MDA-MB-231 (F), and U87mg (G). RKO

cells exhibited extremely high sensitivity to ORL (H). A schematic diagram of the experiment is shown at the bottom

indicating when pre-incubations and media changes occur for each set of experiments.

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Inhibition of 14C-acetate uptake into lipids was then further examined using

pre-incubated ORL and Nano-ORL in order to determine if pre-incubation of ORL

had an effect on lipid synthesis. Conditions were identical to the previous study

with the exception that two groups were added, free ORL or Nano-ORL receiving

a 24 hour pre-incubation. Figure 5-4 shows that all groups containing free ORL

or Nano-ORL inhibit lipid synthesis to a similar degree within each cell line,

regardless of whether the formulation had been pre-incubated or not. Between

groups containing a formulation of ORL, only Nano-ORL (pre-incubated) was

found to be slightly higher than free ORL (not incubated), (95% CI: 1.8 – 39.8%).

However, these data result from level of lipid synthesis after a 17-18 hour

exposure to Nano-ORL, indicating that the toxicity previously observed over 48

hours may be resulting from the additional 30 hours of exposure time.

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Figure 5-4. Pre-incubation of free ORL and Nano-ORL showed similar levels of

lipid inhibition as shown by 14C-acetate uptake. Groups containing either pre-

incubated or non-incubated ORL or Nano-ORL were not found to be significantly

different from each other, with the exception of pre-incubated Nano-ORL vs free

ORL (not pre-incubated), [95% CI: 1.764-39.84]. These results generally suggest

that pre-incubation of ORL or Nano-ORL does not have an effect on lipid

syntheses over the 17-18 hour exposure time tested here. This indicates that the

previously observed toxicity over 48 hours may be resulting from the additional

30 hours of exposure, or from effects other than FASN inhibition.

Chemical Stability

In order to determine whether the maintenance of cytotoxicity after pre-

incubation is a result of improved chemical stability or improved colloidal stability,

Nano-ORL and free ORL were incubated in PBS at room temperature for 96

hours, followed by extraction and analysis by mass spectrometry. It was

hypothesized that exposure of ORL to aqueous solution may result in hydrolysis

of the β-lactone ring, thereby reducing the FASN inhibition, while the Nano-ORL

formulation may prevent this hydrolysis. However, as Figure 5-5 shows, the

expected hydrolysis product (MW: 513.76) was not observed in either group.

Instead the mass spectrum shows ORL either protonated or associated with a

positively charged ion (Na+ or K+). This indicates that the increase in cytotoxicity

of Nano-ORL is likely the result of increased solubility and availability to cells.

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Figure 5-5. MS analysis of extracted Nano-ORL (A) and free ORL (B) after 96

hour incubation in PBS. Identical results between (A) and (B), and the absence of

a hydrolysis product at 513.76 indicate that ORL is not chemically degraded in

either formulation in these conditions.

Mitochondrial Respiration Assays

To examine the consequences of ORL and Nano-ORL treatment on

cellular metabolic function, MDA-MB-231 and LNCaP cells were treated with 50

μM ORL or 50 μM Nano-ORL (plus appropriate vehicles) for 16 hours then

subjected to a Seahorse Mitochondrial Stress Assay (Figure 5-6). Nano-ORL

was able to reduce basal mitochondrial respiration by approximately 65% when

compared to treatment with empty NPs (Figure 5-6A, orange and purple lines

prior to oligomycin injection, and Figure 5-6B). Basal respiration is a basic

measure of O2 use by cellular mitochondria. Likewise, Nano-ORL reduced

coupling efficiency, which measures the amount of ATP turnover, by 58% when

compared to treatment with empty NPs (Figure 5-6C&G, orange and purple lines

between FCCP and RTN/AA injections). The ability of Nano-ORL to significantly

reduce mitochondrial function in MDA-MB-231 cells indicates that the cytotoxic

effects observed mentioned previously are due, at least in part, to metabolic

disruption.

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Figure 5-6. 40,000 MDA-MB-231 cells (A-D) or LNCaP cells (E-H) were plated in

an XF24 well plate and allowed to adhere before treatment with Vehicle

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(DMSO/EtOH), empty NPs, (NP), 50 µM free ORL, or 50 µM Nano-ORL for 16

hours. Oxygen consumption rates were measured (A&E) and values

representing basal respiration (B&F), coupling efficiency (C&G), and spare

respiratory capacity (D&H) were quantified with respect to cell number. Nano-

ORL reduced basal mitochondrial respiration (B) and coupling efficiency (C) in

MDA-MB-231 cell, and reduced coupling efficiency in LNCaP cells (G). ORL

reduced coupling efficiency in both MDA-MB-231 and LNCaP cells. Nano-ORL

was superior to ORL at reducing basal respiration in MDA-MB-231 cells, and

overall showed a similar metabolic inhibition as ORL by decreasing basal

metabolism and coupling efficiency by 50% or more. This suggests that Nano-

ORL has a strong ability to perturb mitochondrial function and reduce cellular

metabolism in both breast and prostate cancer cell lines.

Previous in vitro and in vivo results have shown ORL to inhibit FASN,

trigger apoptosis, and inhibit metastasis and angiogenesis.206, 211, 214 Of particular

interest in the investigation of Nano-ORL is the potentially broad applicability of

FASN inhibitors in the treatment of cancer. A growing body of evidence suggests

that reliance on FASN in cancer is nearly ubiquitous and thus presents a

valuable target for therapy.193, 195, 197 Indeed, ORL has been used in pre-clinical

investigations against a number of cancer types, including prostate, gastric, oral,

skin, and leukemia.206, 212-214, 253 In combination, the low bioavailability through

enteric delivery, high degree of hydrophobicity, and potential for off-target effects

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present significant barriers to clinical use of ORL and require novel developments

in new ORL formulations.

Nano-ORL, as demonstrated here, is effectively solubilized by loading into

the hydrophobic core of HLA NPs. The high loading efficiency observed with

Nano-ORL (96.7% ± 2.4%) shows a strong association between ORL and the NP

core. While the observed effective diameters (400-600 nm) are above the ideal

range for delivery through fenestrations in tumor vasculature, the increased

solubility of Nano-ORL will likely increase total bioavailability and thus improve

overall delivery to tumors. Additionally, modification of the polymer molecular

weight or hydrophobic ligand content may allow for further decrease of NP

diameter. The ability to control NP size based on ORL content will likely prove

useful in optimizing biodistribution, circulation time, and ultimately delivery of

ORL to tumors.

The direct inhibition of FASN and decreased lipid synthesis (Figure 5-2)

demonstrate that Nano-ORL has the same molecular activity as free ORL. Nano-

ORL had similar or better FASN-TE inhibition compared to free ORL (Figure 5-

2A). This indicates that the molecular action of Nano-ORL is the same as that of

free ORL, and the observed cytotoxicity results from FASN inhibition. Inhibition of

lipid synthesis as indicated by 14C-acetate uptake was also found to be similar

between free ORL and Nano-ORL, further demonstrating that Nano-ORL has the

same molecular action as free ORL and that Nano-ORL effectively inhibits new

membrane synthesis in cancer cells.

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Analysis of the cytotoxic effect of Nano-ORL on prostate (PC3), breast

(MDA-MB-231), glioma (U87mg), and colorectal (RKO) cancer cell lines

demonstrates the improved stability of the Nano-ORL formulation over free ORL

(Figure 5-3). 48-hour cytotoxicity analysis resulted in higher levels of toxicity

from Nano-ORL as compared to free ORL (Figure 5-3A). In order to show that

this effect was resulting from improved stability of Nano-ORL and not a

concentration effect, both ORL and Nano-ORL were pre-incubated for 24 hours

prior to exposure to cells (Figure 5-3B). This pre-incubation profoundly

demonstrates the maintenance of the cytotoxic effect of Nano-ORL vs. free ORL,

with the relative viability of free ORL-treated cells increasing by 20-30% relative

to the media-only control. The relative viability of Nano-ORL-treated cells was not

observed to change at all, and Nano-ORL was again found to be more cytotoxic

than even non-pre-incubated ORL. This effect clearly demonstrates the potential

advantages of NP encapsulation of ORL and lends further evidence towards the

in vivo potential of Nano-ORL.

Interestingly, inhibition of lipid synthesis was not observed to be different

over a 17 hour incubation when cells were treated with either pre-incubated or

non-pre-incubated ORL formulations (Figure 5-4). While this appears to be in

contrast to the increased relative viability of cells when treated with pre-incubated

free ORL, the 17 hour time point was chosen specifically to avoid complicating

cytotoxic effects, thereby uncoupling the effects of cytotoxicity and lipid synthesis

inhibition. Additionally, the inhibition assay was performed over 17 hours, while

the toxicity assay was performed over 48 hours, which may provide additional

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time for the effects of pre-incubation to manifest. Detailed metabolic analysis also

shows that Nano-ORL decreases basal respiration and coupling efficiency equal

to, or better than, free ORL (Figure 5-6). This indicates that both the total O2

consumed, and ATP turnover, are reduced in cells treated with Nano-ORL or free

ORL. Thus, both ORL and Nano-ORL exhibit a combination of reduced lipid

synthesis and metabolic activity, which results in a cytotoxic effect against cancer

cell lines. Nano-ORL, however, shows superior stability and solubility in aqueous

solution, which results in higher cytotoxicity over extended periods of time.

Overall, these results show that Nano-ORL has the same molecular action as

free ORL, but provides improved bioavailability due to the soluble NP

formulation.

NP based drug formulations have previously demonstrated

improved efficacy in the clinic, most notably in the forms of Doxil and Abraxane,

and numerous pre-clinical studies are underway.254 Our group and others have

recently shown the potential for delivery of small hydrophobic molecules to

tumors by physical entrapment within nano-scale polymeric micelles made with

chemically modified HLA.255, 256 Delivery with these materials have resulted in

relatively high intra-tumoral concentrations of the selected payload, primarily due

to the enhanced permeability and retention effect and improved drug solubility. In

addition to the passive targeting of solid tumors, active targeting against cancer

cells bearing HLA receptors such as CD44 remains a possibility. CD44 has been

recognized as a potential target for acute myeloid leukemia, multiple myeloma,

and chronic lymphocytic leukemia.257-260 ORL has already been shown to be both

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toxic against chronic lymphocytic leukemia primary cells, and substantially more

toxic to these cells than healthy primary B cells.253 More work is thus needed to

investigate the potential for combination CD44 targeting with ORL delivery

formulations for treatment of both solid and non-solid cancers.

Conclusions

This works represents the first investigation into a nanoparticle formulation

of Orlistat. We have shown that this formulation, Nano-ORL, retains the FASN

inhibition of free ORL through direct FASN inhibition and that this results in

decreased lipid synthesis in cells. Nano-ORL also provides longer lasting

cytotoxic efficacy in vitro, likely through improved serum stability and availability.

This also results in modulation of the metabolic activity of cells as observed by

mitchondrial stress test analysis. These results should encourage further

investigations into NP formulations of ORL, and for NP formulations of other

FASN inhibitors as well.

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CHAPTER 6

CONCLUSIONS AND FUTURE DIRECTIONS

Summary of NanoICG Studies

In this work we have shown that nanoscale self-assembled polymeric

micelle formulations of modified HLA polymers can be used as delivery systems

for ICG and ORL. A novel hydrophobic conjugate, PBA, was synthesized and

conjugated to HLA, resulting in self-assembly in aqueous solution and

entrapment of both ICG and ORL. Comparison to previously examined

hydrophobic conjugates 5βCA and ODA showed that hydrophobic conjugates

with roughly similar structures (PBA and 5βCA) provided similar levels of ICG

loading, whereas octadecylamine conjugates exhibited lower ICG loading and

also required lower conjugation ratios for soluble micelle formation. Loading of

ICG within the hydrophobic regions of NPs resulted in improved solubility in salt

solution, and this process was dependent on the ICG loading step. These

formulations were non-toxic at physiologically relevant concentrations. NanoICG

was not found to actively target CD44+ tumor cells, suggesting that any increase

in signal seen in vivo would be the result of passive targeting resulting from NP

accumulation. In vivo results using NanoICG to highlight tumors suggested that

NanoICG provides approximately twice the contrast between tumor tissue and

muscle at 24 hours compared to injection of free ICG making this formulation a

candidate for further investigations into its usefulness as an image guided

surgery contrast agent.

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Biodistribution and ICG Release to Serum Proteins

Further work is necessary to elucidate the details regarding the release

profile of ICG in serum-mimicking flow conditions (Figure 3-7). Dissolution of

NanoICG into 37 mg/ml BSA-PBS solution (an average physiological

concentration) resulted in rapid release of ICG from NPs to serum proteins. This

release occurs to a significant extent immediately upon dissolution in BSA-PBS

solution, and increasing levels of volumetric flow result in increasing ICG release

to serum proteins. The WSS in an idealized cylindrical vessel at the liquid-solid

boundary, where shear stress is highest, is shown in Equation 6.1:

GH = 32JKL4M

[6.1]

where τω = wall shear stress (dyne/cm2), Q = volumetric flow rate, µ = viscosity,

D = diameter. Theoretical values calculated using Equation 6.1 for the flow rates

in this experiment range from 0.287-2.58 dyne/cm2. Using these values will result

in underestimation of the actual shear stress experience by the NPs as the

peristaltic pump action will result in transiently higher shear values as the fluid

passes the pump head. Thus, a safe approximation for maximum shear stress

experienced in this experiment is on the order of 10 dyne/cm2. However,

physiological shear stress values range from 50 dyne/cm2 in the aorta, 2.8-100

dyne/cm2 in capillaries, and 17-211 dyne/cm2 in arterioles, and even as high as

600 dyne/cm2 in mouse aortas.91-94 Thus, the shear stress experienced in this

system is a gross underestimate of shear stress experienced in humans or the in

vivo model used here, meaning ICG release should actually release more

rapidly. Additionally, we found that dissolution of either ICG or NanoICG in BSA-

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PBS followed by elution through a 100 kDa centrifugal filter kit resulted in similar

elutions of ICG and BSA, indicating that elution was not dependent upon the

initial presence of ICG in the NP formulation (Figure 3-8). These results suggest

that ICG is being released from NanoICG and should thus behave similarly to

free ICG in vivo.

Contrary to the in vitro results, NanoICG appears to behave very much

like a NP in its biodistribution and clearance in mice (Figure 4-1 & 4-4). In vivo

results show that two different NanoICG formulations both result in improved

SNR and CNR compared to free ICG at 24 hours. Kidney signal is higher for ICG

at 4 hours, and similar to NanoICG at 24 hours. These results are consistent with

small molecule clearance for ICG and NP clearance for NanoICG. Additionally,

this work was replicated in two separate animal experiments and with consistent

results. It thus appears that ICG within NPs, while it does release to serum

proteins, still remains within the NPs for some time. This is shown by the gradual

increase in the release profile and likely causes the difference in biodistribution. It

has also been shown that smaller molecules or polymers diffuse more easily

from tumors back into circulation, so that the larger NanoICG particles would be

retained in tumors longer than ICG.97 One possible method to examine this in

vitro would be to use tumors grown in decellularized tissues perfused with

peristaltic pumps. This would allow for the combination of natural-like tumors in

controlled flow conditions, and would afford precise control of solution

composition such as NP and protein concentration. This approach would prevent

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the complications of metabolism and excretion, and could thus focus solely on

release, quenching, flow, and diffusion from tumors.

An additional complicating factor is the total ICG signal in mice at 4 hours,

which shows ICG as being present in higher quantities in all tissues. ICG content

of all contrast agents was measured with absorbance spectrometry prior to

administration, so this is not likely to be a result of higher ICG administration

levels. A possible explanation for this is the quenching phenomenon previously

observed when ICG is closely bound within NanoICG. As the biodistribution

indicates that ICG is retained within NP cores it follows that fluorescence

quenching would also occur, which would reduce the observed signal. A future

pharmacokinetic in vivo study is necessary in which ICG is extracted from tissues

at various timepoints and more rigorously quantified in order to prevent

systematic error due to quenching of NanoICG. The ICG release to serum

proteins should also be further examined to determine to what extent ICG is

released from NanoICG at various timepoints, and what effect solution

composition has on this release.

Though NanoICG shows significantly higher CNR than free ICG, it may be

possible to improve this further by controlling ICG release from the NPs. In order

to prevent the loss of ICG to serum proteins, chemical modifications to NanoICG

will be necessary. The most obvioius potential modification is PEGylation, which

as been clearly demonstrated to reduce interactions with serum proteins in

numerous studies.86 This type of modification could be performed using the same

chemistry required for conjugation of the hydrophobic groups to HLA, namely

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amide bond formation between a primary amine on a PEG molecule and the

carboxylic acid on HLA by EDC/NHS reaction. This method has been used

previously with Cy5.5 labeled HLA, where PEGylation resulted in increased

retention within the tumor and within the entire body, as well as lower relative

uptake by the liver.50 Another strategy to prevent loss of the fluorophore from the

NPs is through direct conjugation to HLA. Previous studies have investigated

direct conjugation of ICG-OSU, an N-hydroxysuccinimide activated form of ICG,

as well as direct conjugation of Cy5.5.50, 228 Furthermore, chemical crosslinking of

the HLA polymers could prevent dissociation and ensure that NPs remain intact

during tumor accumulation. However, direct conjugation of fluorophores to HLA

requires the use of non-FDA approved materials, significantly reducing the ease

and speed of clinical translation. An alternative strategy to avoid this complication

would be to test alternative NP formulations by utilizing different polymers. Other

groups have successfully loaded ICG into PLGA or PLA based NPs, and a

number of polymeric or liposomal formulations may need to be investigated in

order to acquire optimal release kinetics and biodistribution.220, 233, 261-263

An IGS-Specific Animal Model is Needed

Further addressing the in vivo issues in IGS is the choice of animal model.

New tumor models specifically considering the experimental requirements of IGS

are needed. Mice provide high sample sizes but their physical dimensions

prevent adequate separation of metabolic and excretory organs from target

tissues (Figure 4-7). Additionally, for breast cancer models in particular, mice

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provide little breast tissue with which to examine contrast between tumors and

healthy tissue. Subcutaneous tumor models in which the tumor is placed in the

back hip, as in Figure 4-3, provide the best optical protection of the tumor signal

from the signal of visceral organs such as the liver and kidneys, but this location

does not provide tumor orthotopic growth as would be found by injection into

breast tissue. The studies demonstrated here have demonstrated the superior

tumor distribution of NanoICG, but future in vivo studies will require survival

surgery and direct comparison of contrast between target tissues. Thus, a

different animal model, using a larger animal with orthotopic tumors, is necessary

to gain a complete understanding of expected contrast between tumors and

various tissues in a surgical setting. Some investigations into this have been

performed in spontaneously occurring tumors in canines, which provides

advantages in both animal size as well as natural tumor formation that provides

realistic contrast agent distribution.230 However, this method is not reasonable for

routine work due to limitations on animal patient populations. One appropriate

animal may be rats, which are substantially larger than mice while smaller than

many other research species.

Extension of NanoICG to SLN Mapping

The current gold standard for SLN mapping involves radioisotope probes

or the visual dye Patent blue.177 ICG alone has previously shown success as

both a color and fluorescent dye in SLN mapping, with rates comparable to

radioisotope probes. HLA has also shown success in improving SLN mapping by

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mixing with Patent blue or SPIO NPs, as free HLA increased the viscosity of the

solution, which prolonged the duration of stain within the SLN.62 NanoICG clearly

shows increased retention within the tumor over free ICG, and would likely serve

equally well or better than free ICG to image SLNs. Additionally, the ratio of ICG

to HLA could easily be tailored to result in a higher viscosity solution and possibly

decrease the quenching effect, which could further improve the retention and

signal present for quick imaging. Using NIR imaging with ICG would serve both

to provide surgeons with visual feedback as opposed to lymphoscintigraphy, and

would decrease the radiation exposure of both patients and operating room staff.

Summary of Nano-ORL Studies

The Nano-ORL work presented here represents the first NP formulation of

ORL. ORL was efficiently loaded into the NP cores (Figure 5-1A), which

demonstrates its highly hydrophobic nature. Nano-ORL was also found to inhibit

FASN and block lipid synthesis in vitro, indicating that the molecular action of

Nano-ORL is the same as that of ORL, and that the NP loading process does not

cause ORL degradation (Figure 5-2A&B). Toxicity against cancer cell lines was

found with both Nano-ORL and ORL, except that Nano-ORL appeared to be

more toxic than free ORL over 48 hours (Figure 5-3). This additional toxicity was

not due to negative effects of the NP material itself, as empty NPs were not

found to be toxic. Thus, the greater cytotoxicity must result from a synergistic

effect of the Nano-ORL formulation. It was hypothesized that the Nano-ORL

formulation provides better aqueous stability of ORL, thus increasing the total

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exposure to the cells. Pre-incubation of both ORL and Nano-ORL resulted in

greatly reduced cytotoxicity of ORL, while the toxicity of Nano-ORL was not

effected. This indicates that the aqueous stability of ORL is increased when

loaded into the hydrophobic cores of NPs. Further analysis indicated that the

toxic effect of both ORL and Nano-ORL resulted in decreased metabolic activity

of the cells due to perturbed mitochondrial function (Figure 5-7).

Diameter of Nano-ORL

Further work is needed with regard to the average NP size. Figure 5-1B

indicates that the average diameter of Nano-ORL loaded with 20 wt% ORL is

approximately 600 nm, while that of 5 wt% is approximately 400 nm. These

diameters are too large to fit through the vascular fenestrations of many tumors.

Though many complicating and competing factors must be addressed in NP

biodistribution, NPs of 100 nm in diameter have been found to be appropriate in

many situations.82 For delivery to solid tumors, it will thus be preferable to

develop a formulation with signficantly smaller average diameters than what we

have observed with 10 kDa High-PBA-HLA. Alternatives exist in the form of other

polymeric or liposomal formulations, as these have commonly been used in NP

drug delivery as outlined previously, however the exact composition will need to

be determined experimentally.

Despite the non-optimal diameters, the increased solubility of Nano-ORL

will likely increase total bioavailability and thus improve overall delivery to tumors.

Additionally, modification of the HLA molecular weight or hydrophobic ligand

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content may allow for further decrease of NP diameter. Additionally, the ability to

control NP size based on ORL content will likely prove useful in optimizing

biodistribution, circulation time, and ultimately delivery of ORL to tumors.

In Vivo Testing of Nano-ORL

It is desirable to begin in vivo studies using Nano-ORL. The improved

aqueous stability and prolonged activity observed are sufficient reason for initial

investigations into the anti-tumor activity in living animals. No previous in vivo

experiments have utilized systemic injection of ORL,211-213 and thus both efficacy

and toxicity studies are needed. Possible side effects of ORL administration are

likely to be similar to those observed with C75, including weight loss and

anorexia,195, 201, and ORL is known to be active against pancreatic lipases,

FASN, lipoprotein lipase, and potentially GADPH and β-tubulin as well.253, 264

However, despite these potential complications, the potential beneficial outcomes

of systemic administration of a solubilized form of ORL must be addressed. The

in vitro results presented in this work demonstrate significant and meaningful

improvements in the action of ORL against cancer cells. Additionally, previous

NP formulations of other drugs, such as Doxil®, have resulted in lower off-target

toxicities compared to the free drug, so it is reasonable to expect that a NP

formulation of ORL could exhibit this behavior as well.

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HLA Remains a Suitable Biopolymer for NP Research

HLA has been, and remains, a useful biopolymer for the synthesis of

nanoscale polymeric micelles. However, HLA has both positive and negative

aspects for use as a NP backbone. Benefits include the biodegradability,

hydrophilic nature, potential for active targeting against CD44, multivalency for

hydrophobic moiety, stealth moiety, drug, or targeting ligand conjugation.

Detriments include the molecular effects of different molecular weight HLA

polymers, as large MW HLA is antiangiogenic and immunosuppressive, while

small (20 kDa) MW HLA is angiogenic and inflammatory.265 The polydispersity of

both natural and commercial HLA, and the multivalency resulting in non-location-

specific conjugation also result in a diversity of similar products formed in the

same reaction. Simply, HLA is difficult to precisly control on a molecular level. As

such, its limitations and variations should be recognized and addressed prior to

utilizing HLA in new formulations. Nonetheless, it remains a highly useful polymer

for NP formulations and the applications will doubtlessly expand.

Conclusion

The field of nanomedicine is expanding rapidly and for good reason.

Nanomedicines have shown numerous advantages over their free drug

counterparts both pre-clinically and clinically, a number of which are evidenced

here in the form of superior tumor contrast from ICG delivery and prolonged

cytotoxic effects with ORL. Though there are significant hurdles in the delivery of

NPs to tumors, in many ways what remains is an optimization problem rather

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than proof of efficacy. Optimization must occur in the form of NP size, stability,

drug release rate, charge, and targeting. This will require novel contributions in

the form of combinations and modifications of materials. Material choice will

depend on the drugs or contrast agents being delivered, which in turn depend on

the cellular and extracellular biochemical and biophysical environment that is

being targeted. Related to the field of personalized genetic medicine, one can

envision a field of personalized nanomedicine in which optimized NP

formulations may be chosen based on an individual tumor’s expected attributes,

such as vascularity, fenestration size, and predicted susceptibility to various

chemotherapeutics. This could allow better outcomes at every stage of the

cancer treatment process, from improved diagnosis, staging and restaging,

optimized visualization during surgical resection, to improved chemotherapeutic

outcomes.

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Works Cited

1. Petros, R. A.; DeSimone, J. M. Strategies in the design of nanoparticles for therapeutic applications. Nat. Rev. Drug Discov. 2010, 9, (8), 615-627.

2. Miele, E.; Spinelli, G. P.; Miele, E.; Tomao, F.; Tomao, S. Albumin-bound formulation of paclitaxel (Abraxane (R) ABI-007) in the treatment of breast cancer. Int. J. Nanomed. 2009, 4, (1), 99-105.

3. Chang, H. I.; Yeh, M. K. Clinical development of liposome-based drugs: formulation, characterization, and therapeutic efficacy. Int. J. Nanomed. 2012, 7, 49-60.

4. O'Brien, M. E. R.; Wigler, N.; Inbar, M.; Rosso, R.; Grischke, E.; Santoro, A.; Catane, R.; Kieback, D. G.; Tomczak, P.; Ackland, S. P.; Orlandi, F.; Mellars, L.; Alland, L.; Tendler, C.; Grp, C. B. C. S. Reduced cardiotoxicity and comparable efficacy in a phase III trial of pegylated liposomal doxorubicin HCl (CAELYX (TM)/Doxil (R)) versus conventional doxorubicin for first-line treatment of metastatic breast cancer. Annals of Oncology 2004, 15, (3), 440-449.

5. Barenholz, Y. Doxil (R) - The first FDA-approved nano-drug: Lessons learned. J. Control. Release 2012, 160, (2), 117-134.

6. Allen, T. M.; Cullis, P. R. Liposomal drug delivery systems: from concept to clinical applications. Advanced drug delivery reviews 2013, 65, (1), 36-48.

7. Petersen, A. L.; Hansen, A. E.; Gabizon, A.; Andresen, T. L. Liposome imaging agents in personalized medicine. Advanced drug delivery reviews 2012, 64, (13), 1417-1435.

8. Daniel, M. C.; Astruc, D. Gold nanoparticles: Assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology. Chemical Reviews 2004, 104, (1), 293-346.

9. Mieszawska, A. J.; Mulder, W. J. M.; Fayad, Z. A.; Cormode, D. P. Multifunctional Gold Nanoparticles for Diagnosis and Therapy of Disease. Molecular pharmaceutics 2013, 10, (3), 831-847.

10. Dreaden, E. C.; Alkilany, A. M.; Huang, X.; Murphy, C. J.; El-Sayed, M. A. The golden age: gold nanoparticles for biomedicine. Chemical Society reviews 2012, 41, (7), 2740-79.

Page 168: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

153

11. Cheng, Y.; Samia, A. C.; Meyers, J. D.; Panagopoulos, I.; Fei, B. W.; Burda, C. Highly efficient drug delivery with gold nanoparticle vectors for in vivo photodynamic therapy of cancer. J. Am. Chem. Soc. 2008, 130, (32), 10643-10647.

12. Liu, Y.; Shipton, M. K.; Ryan, J.; Kaufman, E. D.; Franzen, S.; Feldheim, D. L. Synthesis, stability, and cellular internalization of gold nanoparticles containing mixed peptide-poly(ethylene glycol) monolayers. Analytical Chemistry 2007, 79, (6), 2221-2229.

13. Dreaden, E. C.; Mwakwari, S. C.; Sodji, Q. H.; Oyelere, A. K.; El-Sayed, M. A. Tamoxifen-Poly(ethylene glycol)-Thiol Gold Nanoparticle Conjugates: Enhanced Potency and Selective Delivery for Breast Cancer Treatment. Bioconjugate chemistry 2009, 20, (12), 2247-2253.

14. Wang, Y.; Angelatos, A. S.; Caruso, F. Template synthesis of nanostructured materials via layer-by-layer assembly. Chemistry of Materials 2008, 20, (3), 848-858.

15. Alric, C.; Taleb, J.; Le Duc, G.; Mandon, C.; Billotey, C.; Le Meur-Herland, A.; Brochard, T.; Vocanson, F.; Janier, M.; Perriat, P.; Roux, S.; Tillement, O. Gadolinium chelate coated gold nanoparticles as contrast agents for both X-ray computed tomography and magnetic resonance imaging. J. Am. Chem. Soc. 2008, 130, (18), 5908-5915.

16. Park, H.; Yang, J.; Lee, J.; Haam, S.; Choi, I.-H.; Yoo, K.-H. Multifunctional Nanoparticles for Combined Doxorubicin and Photothermal Treatments. Acs Nano 2009, 3, (10), 2919-2926.

17. Jang, B.; Park, J. Y.; Tung, C. H.; Kim, I. H.; Choi, Y. Gold Nanorod-Photosensitizer Complex for Near-Infrared Fluorescence Imaging and Photodynamic/Photothermal Therapy In Vivo. Acs Nano 2011, 5, (2), 1086-1094.

18. Wu, X.; He, X. X.; Wang, K. M.; Xie, C.; Zhou, B.; Qing, Z. H. Ultrasmall near-infrared gold nanoclusters for tumor fluorescence imaging in vivo. Nanoscale 2010, 2, (10), 2244-2249.

19. Wu, Z. K.; Jin, R. C. On the Ligand's Role in the Fluorescence of Gold Nanoclusters. Nano letters 2010, 10, (7), 2568-2573.

20. Bao, G.; Mitragotri, S.; Tong, S. Multifunctional Nanoparticles for Drug Delivery and Molecular Imaging. Annual Review of Biomedical Engineering 2013, 15, (1), 253-282.

Page 169: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

154

21. Veiseh, O.; Gunn, J. W.; Zhang, M. Design and fabrication of magnetic nanoparticles for targeted drug delivery and imaging. Advanced drug delivery reviews 2010, 62, (3), 284-304.

22. Sonvico, F.; Mornet, S.; Vasseur, S.; Dubernet, C.; Jaillard, D.; Degrouard, J.; Hoebeke, J.; Duguet, E.; Colombo, P.; Couvreur, P. Folate-Conjugated Iron Oxide Nanoparticles for Solid Tumor Targeting as Potential Specific Magnetic Hyperthermia Mediators: Synthesis, Physicochemical Characterization, and in Vitro Experiments. Bioconjugate chemistry 2005, 16, (5), 1181-1188.

23. Gupta, A. K.; Gupta, M. Synthesis and surface engineering of iron oxide nanoparticles for biomedical applications. Biomaterials 2005, 26, (18), 3995-4021.

24. Kievit, F. M.; Zhang, M. Surface Engineering of Iron Oxide Nanoparticles for Targeted Cancer Therapy. Accounts of Chemical Research 2011, 44, (10), 853-862.

25. Ito, A.; Kuga, Y.; Honda, H.; Kikkawa, H.; Horiuchi, A.; Watanabe, Y.; Kobayashi, T. Magnetite nanoparticle-loaded anti-HER2 immunoliposomes for combination of antibody therapy with hyperthermia. Cancer letters 2004, 212, (2), 167-175.

26. Smith, A. M.; Duan, H.; Mohs, A. M.; Nie, S. Bioconjugated quantum dots for in vivo molecular and cellular imaging. Advanced drug delivery reviews 2008, 60, (11), 1226-40.

27. Mattoussi, H.; Palui, G.; Na, H. B. Luminescent quantum dots as platforms for probing in vitro and in vivo biological processes. Advanced drug delivery reviews 2012, 64, (2), 138-166.

28. Jaiswal, J. K.; Mattoussi, H.; Mauro, J. M.; Simon, S. M. Long-term multiple color imaging of live cells using quantum dot bioconjugates. Nature Biotechnology 2003, 21, (1), 47-51.

29. Kim, S.; Lim, Y. T.; Soltesz, E. G.; De Grand, A. M.; Lee, J.; Nakayama, A.; Parker, J. A.; Mihaljevic, T.; Laurence, R. G.; Dor, D. M.; Cohn, L. H.; Bawendi, M. G.; Frangioni, J. V. Near-infrared fluorescent type II quantum dots for sentinel lymph node mapping. Nature Biotechnology 2004, 22, (1), 93-97.

30. Lin, Y. H.; Chung, C. K.; Chen, C. T.; Liang, H. F.; Chen, S. C.; Sung, H. W. Preparation of nanoparticles composed of chitosan/poly-gamma-glutamic acid and evaluation of their permeability through Caco-2 cells. Biomacromolecules 2005, 6, (2), 1104-1112.

Page 170: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

155

31. Zhang, S.; Chan, K. H.; Prud'homme, R. K.; Link, A. J. Synthesis and Evaluation of Clickable Block Copolymers for Targeted Nanoparticle Drug Delivery. Molecular pharmaceutics 2012, 9, (8), 2228-2236.

32. Zhang, Y.; Tang, L.; Sun, L.; Bao, J.; Song, C.; Huang, L.; Liu, K.; Tian, Y.; Tian, G.; Li, Z.; Sun, H.; Mei, L. A novel paclitaxel-loaded poly(ε-caprolactone)/Poloxamer 188 blend nanoparticle overcoming multidrug resistance for cancer treatment. Acta Biomaterialia 2010, 6, (6), 2045-2052.

33. Etrych, T.; Šírová, M.; Starovoytova, L.; Říhová, B.; Ulbrich, K. HPMA Copolymer Conjugates of Paclitaxel and Docetaxel with pH-Controlled Drug Release. Molecular pharmaceutics 2010, 7, (4), 1015-1026.

34. Hamidi, M.; Azadi, A.; Rafiei, P. Hydrogel nanoparticles in drug delivery. Advanced drug delivery reviews 2008, 60, (15), 1638-1649.

35. Liu, Z.; Jiao, Y.; Wang, Y.; Zhou, C.; Zhang, Z. Polysaccharides-based nanoparticles as drug delivery systems. Advanced drug delivery reviews 2008, 60, (15), 1650-1662.

36. Kim, T. Y.; Kim, D. W.; Chung, J. Y.; Shin, S. G.; Kim, S. C.; Heo, D. S.; Kim, N. K.; Bang, Y. J. Phase I and pharmacokinetic study of Genexol-PM, a cremophor-free, polymeric micelle-formulated paclitaxel, in patients with advanced malignancies. Clinical Cancer Research 2004, 10, (11), 3708-3716.

37. Clinicaltrials.gov, Evaluate the Efficacy and Safety of Genexol-PM Compared to Genexol in Recurrent or Metastatic Breast Cancer. In NCT00876486, Corp., S. B., Ed. Clinicaltrials.gov: https://clinicaltrials.gov/show/NCT00876486, 2012.

38. Gelderblom, H.; Verweij, J.; Nooter, K.; Sparreboom, A. Cremophor EL: the drawbacks and advantages of vehicle selection for drug formulation. European Journal of Cancer 2001, 37, (13), 1590-1598.

39. Nitta, S. K.; Numata, K. Biopolymer-Based Nanoparticles for Drug/Gene Delivery and Tissue Engineering. International Journal of Molecular Sciences 2013, 14, (1), 1629-1654.

40. Robin, M. P.; O'Reilly, R. K. Strategies for preparing fluorescently labelled polymer nanoparticles. Polymer International 2015, 64, (2), 174-182.

41. Sailor, M. J.; Park, J. H. Hybrid Nanoparticles for Detection and Treatment of Cancer. Advanced materials 2012, 24, (28), 3779-3802.

Page 171: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

156

42. Toole, B. P. Hyaluronan: From extracellular glue to pericellular cue. Nat. Rev. Cancer 2004, 4, (7), 528-539.

43. Kogan, G.; Soltes, L.; Stern, R.; Gemeiner, P. Hyaluronic acid: a natural biopolymer with a broad range of biomedical and industrial applications. Biotechnology Letters 2007, 29, (1), 17-25.

44. Laurent, T. C.; Fraser, J. R. E. HYALURONAN. Faseb Journal 1992, 6, (7), 2397-2404.

45. Hargittai, I.; Hargittai, M. Molecular structure of hyaluronan: an introduction. Structural Chemistry 2008, 19, (5), 697-717.

46. Ekici, S.; Cerwinka, W. H.; Civantos, F.; Soloway, M. S.; Lokeshwar, V. B. Comparison of the prognostic potential of hyaluronic acid, hyaluronidase(HYAL-1), CD44v6 and microvessel density for prostate cancer. International journal of cancer. Journal international du cancer 2004, 112, (1), 121-129.

47. Udabage, L.; Brownlee, G. R.; Nilsson, S. K.; Brown, T. J. The over-expression of HAS2, Hyal-2 and CD44 is implicated in the invasiveness of breast cancer. Experimental cell research 2005, 310, (1), 205-17.

48. Ponta, H.; Sherman, L.; Herrlich, P. A. CD44: From adhesion molecules to signalling regulators. Nature Reviews Molecular Cell Biology 2003, 4, (1), 33-45.

49. Choi, K. Y.; Min, K. H.; Na, J. H.; Choi, K.; Kim, K.; Park, J. H.; Kwon, I. C.; Jeong, S. Y. Self-assembled hyaluronic acid nanoparticles as a potential drug carrier for cancer therapy: synthesis, characterization, and in vivo biodistribution. Journal of Materials Chemistry 2009, 19, (24), 4102-4107.

50. Choi, K. Y.; Min, K. H.; Yoon, H. Y.; Kim, K.; Park, J. H.; Kwon, I. C.; Choi, K.; Jeong, S. Y. PEGylation of hyaluronic acid nanoparticles improves tumor targetability in vivo. Biomaterials 2011, 32, (7), 1880-1889.

51. Choi, K. Y.; Yoon, H. Y.; Kim, J.-H.; Bae, S. M.; Park, R.-W.; Kang, Y. M.; Kim, I.-S.; Kwon, I. C.; Choi, K.; Jeong, S. Y.; Kim, K.; Park, J. H. Smart Nanocarrier Based on PEGylated Hyaluronic Acid for Cancer Therapy. ACS Nano 2011, 5, (11), 8591-8599.

52. Choi, K. Y.; Silvestre, O. F.; Huang, X.; Hida, N.; Liu, G.; Ho, D. N.; Lee, S.; Lee, S. W.; Hong, J. I.; Chen, X. A nanoparticle formula for delivering siRNA

Page 172: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

157

or miRNAs to tumor cells in cell culture and in vivo. Nat. Protocols 2014, 9, (8), 1900-1915.

53. Yoon, H. Y.; Koo, H.; Choi, K. Y.; Lee, S. J.; Kim, K.; Kwon, I. C.; Leary, J. F.; Park, K.; Yuk, S. H.; Park, J. H.; Choi, K. Tumor-targeting hyaluronic acid nanoparticles for photodynamic imaging and therapy. Biomaterials 2012, 33, (15), 3980-3989.

54. Zhang, L. W.; Gao, S.; Zhang, F.; Yang, K.; Ma, Q. J.; Zhu, L. Activatable Hyaluronic Acid Nanoparticle as a Theranostic Agent for Optical/Photoacoustic Image-Guided Photothermal Therapy. Acs Nano 2014, 8, (12), 12250-12258.

55. Wu, J.-l.; Liu, C.-g.; Wang, X.-l.; Huang, Z.-h. Preparation and characterization of nanoparticles based on histidine-hyaluronic acid conjugates as doxorubicin carriers. Journal of Materials Science-Materials in Medicine 2012, 23, (8), 1921-1929.

56. Cho, H.-J.; Yoon, H. Y.; Koo, H.; Ko, S.-H.; Shim, J.-S.; Lee, J.-H.; Kim, K.; Kwon, I. C.; Kim, D.-D. Self-assembled nanoparticles based on hyaluronic acid-ceramide (HA-CE) and Pluronic® for tumor-targeted delivery of docetaxel. Biomaterials 2011, 32, (29), 7181-7190.

57. Cho, H.-J.; Yoon, I.-S.; Yoon, H. Y.; Koo, H.; Jin, Y.-J.; Ko, S.-H.; Shim, J.-S.; Kim, K.; Kwon, I. C.; Kim, D.-D. Polyethylene glycol-conjugated hyaluronic acid-ceramide self-assembled nanoparticles for targeted delivery of doxorubicin. Biomaterials 2012, 33, (4), 1190-1200.

58. Jeong, Y.-I.; Kim, D. H.; Chung, C.-W.; Yoo, J. J.; Choi, K. H.; Kim, C. H.; Ha, S. H.; Kang, D. H. Self-assembled nanoparticles of hyaluronic acid/poly(DL-lactide-co-glycolide) block copolymer. Colloids and Surfaces B-Biointerfaces 2012, 90, 28-35.

59. de la Fuente, M.; Seijo, B.; Alonso, M. J. Novel hyaluronic acid-chitosan nanoparticles for ocular gene therapy. Investigative Ophthalmology & Visual Science 2008, 49, (5), 2016-2024.

60. El-Dakdouki, M. H.; Zhu, D. C.; El-Boubbou, K.; Kamat, M.; Chen, J.; Li, W.; Huang, X. Development of Multifunctional Hyaluronan-Coated Nanoparticles for Imaging and Drug Delivery to Cancer Cells. Biomacromolecules 2012, 13, (4), 1144-1151.

61. Lee, H.; Lee, M.-Y.; Bhang, S. H.; Kim, B.-S.; Kim, Y. S.; Ju, J. H.; Kim, K. S.; Hahn, S. K. Hyaluronate–Gold Nanoparticle/Tocilizumab Complex for the Treatment of Rheumatoid Arthritis. ACS Nano 2014, 8, (5), 4790-4798.

Page 173: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

158

62. Kitayama, J.; Ishigami, H.; Ishikawa, M.; Yamashita, H.; Soma, D.; Miyato, H.; Nagawa, H. Hyaluronic acid is a useful tool for intraoperative sentinel node detection in gastric cancer surgery. Surgery 2007, 141, (6), 815-820.

63. Choi, K. Y.; Chung, H.; Min, K. H.; Yoon, H. Y.; Kim, K.; Park, J. H.; Kwon, I. C.; Jeong, S. Y. Self-assembled hyaluronic acid nanoparticles for active tumor targeting. Biomaterials 2010, 31, (1), 106-114.

64. Park, J.-H.; Lee, J.-Y.; Termsarasab, U.; Yoon, I.-S.; Ko, S.-H.; Shim, J.-S.; Cho, H.-J.; Kim, D.-D. Development of poly(lactic-co-glycolic) acid nanoparticles-embedded hyaluronic acid–ceramide-based nanostructure for tumor-targeted drug delivery. International Journal of Pharmaceutics 2014, 473, (1–2), 426-433.

65. Jin, Y.-J.; Termsarasab, U.; Ko, S.-H.; Shim, J.-S.; Chong, S.; Chung, S.-J.; Shim, C.-K.; Cho, H.-J.; Kim, D.-D. Hyaluronic Acid Derivative-Based Self-Assembled Nanoparticles for the Treatment of Melanoma. Pharmaceutical Research 2012, 29, (12), 3443-3454.

66. Yoon, H. Y.; Koo, H.; Choi, K. Y.; Chan Kwon, I.; Choi, K.; Park, J. H.; Kim, K. Photo-crosslinked hyaluronic acid nanoparticles with improved stability for in vivo tumor-targeted drug delivery. Biomaterials 2013, 34, (21), 5273-5280.

67. Al-Ghananeem, A. M.; Malkawi, A. H.; Muammer, Y. M.; Balko, J. M.; Black, E. P.; Mourad, W.; Romond, E. Intratumoral Delivery of Paclitaxel in Solid Tumor from Biodegradable Hyaluronan Nanoparticle Formulations. Aaps Pharmscitech 2009, 10, (2), 410-417.

68. Kim, H.; Park, H. T.; Tae, Y. M.; Kong, W. H.; Sung, D. K.; Hwang, B. W.; Kim, K. S.; Kim, Y. K.; Hahn, S. K. Bioimaging and pulmonary applications of self-assembled Flt1 peptide–hyaluronic acid conjugate nanoparticles. Biomaterials 2013, 34, (33), 8478-8490.

69. Huang, J.; Zhang, H.; Yu, Y.; Chen, Y.; Wang, D.; Zhang, G.; Zhou, G.; Liu, J.; Sun, Z.; Sun, D.; Lu, Y.; Zhong, Y. Biodegradable self-assembled nanoparticles of poly (d,l-lactide-co-glycolide)/hyaluronic acid block copolymers for target delivery of docetaxel to breast cancer. Biomaterials 2014, 35, (1), 550-566.

70. Ganesh, S.; Iyer, A. K.; Morrissey, D. V.; Amiji, M. M. Hyaluronic acid based self-assembling nanosystems for CD44 target mediated siRNA delivery to solid tumors. Biomaterials 2013, 34, (13), 3489-3502.

Page 174: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

159

71. Lu, H.-D.; Zhao, H.-Q.; Wang, K.; Lv, L.-L. Novel hyaluronic acid–chitosan nanoparticles as non-viral gene delivery vectors targeting osteoarthritis. International Journal of Pharmaceutics 2011, 420, (2), 358-365.

72. Raviña, M.; Cubillo, E.; Olmeda, D.; Novoa-Carballal, R.; Fernandez-Megia, E.; Riguera, R.; Sánchez, A.; Cano, A.; Alonso, M. Hyaluronic Acid/Chitosan-g-Poly(ethylene glycol) Nanoparticles for Gene Therapy: An Application for pDNA and siRNA Delivery. Pharmaceutical Research 2010, 27, (12), 2544-2555.

73. Duceppe, N.; Tabrizian, M. Factors influencing the transfection efficiency of ultra low molecular weight chitosan/hyaluronic acid nanoparticles. Biomaterials 2009, 30, (13), 2625-2631.

74. Oyarzun-Ampuero, F. A.; Brea, J.; Loza, M. I.; Torres, D.; Alonso, M. J. Chitosan–hyaluronic acid nanoparticles loaded with heparin for the treatment of asthma. International Journal of Pharmaceutics 2009, 381, (2), 122-129.

75. Kamat, M.; El-Boubbou, K.; Zhu, D. C.; Lansdell, T.; Lu, X.; Li, W.; Huang, X. Hyaluronic Acid Immobilized Magnetic Nanoparticles for Active Targeting and Imaging of Macrophages. Bioconjugate chemistry 2010, 21, (11), 2128-2135.

76. Lee, M.-Y.; Yang, J.-A.; Jung, H. S.; Beack, S.; Choi, J. E.; Hur, W.; Koo, H.; Kim, K.; Yoon, S. K.; Hahn, S. K. Hyaluronic Acid–Gold Nanoparticle/Interferon α Complex for Targeted Treatment of Hepatitis C Virus Infection. ACS Nano 2012, 6, (11), 9522-9531.

77. Lee, H.; Lee, K.; Kim, I. K.; Park, T. G. Synthesis, characterization, and in vivo diagnostic applications of hyaluronic acid immobilized gold nanoprobes. Biomaterials 2008, 29, (35), 4709-4718.

78. Wang, D.; Huang, J.; Wang, X.; Yu, Y.; Zhang, H.; Chen, Y.; Liu, J.; Sun, Z.; Zou, H.; Sun, D.; Zhou, G.; Zhang, G.; Lu, Y.; Zhong, Y. The eradication of breast cancer cells and stem cells by 8-hydroxyquinoline-loaded hyaluronan modified mesoporous silica nanoparticle-supported lipid bilayers containing docetaxel. Biomaterials 2013, 34, (31), 7662-7673.

79. Cohen, K.; Emmanuel, R.; Kisin-Finfer, E.; Shabat, D.; Peer, D. Modulation of Drug Resistance in Ovarian Adenocarcinoma Using Chemotherapy Entrapped in Hyaluronan-Grafted Nanoparticle Clusters. ACS Nano 2014, 8, (3), 2183-2195.

Page 175: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

160

80. Rivkin, I.; Cohen, K.; Koffler, J.; Melikhov, D.; Peer, D.; Margalit, R. Paclitaxel-clusters coated with hyaluronan as selective tumor-targeted nanovectors. Biomaterials 2010, 31, (27), 7106-7114.

81. Lee, M. S.; Lee, J. E.; Byun, E.; Kim, N. W.; Lee, K.; Lee, H.; Sim, S. J.; Lee, D. S.; Jeong, J. H. Target-specific delivery of siRNA by stabilized calcium phosphate nanoparticles using dopa–hyaluronic acid conjugate. J. Control. Release 2014, 192, (0), 122-130.

82. Bertrand, N.; Wu, J.; Xu, X.; Kamaly, N.; Farokhzad, O. C. Cancer nanotechnology: The impact of passive and active targeting in the era of modern cancer biology. Advanced drug delivery reviews 2014, 66, 2-25.

83. Jokerst, J. V.; Lobovkina, T.; Zare, R. N.; Gambhir, S. S. Nanoparticle PEGylation for imaging and therapy. Nanomedicine 2011, 6, (4), 715-728.

84. Ernsting, M. J.; Murakami, M.; Roy, A.; Li, S.-D. Factors controlling the pharmacokinetics, biodistribution and intratumoral penetration of nanoparticles. J. Control. Release 2013, 172, (3), 782-794.

85. Soo Choi, H.; Liu, W.; Misra, P.; Tanaka, E.; Zimmer, J. P.; Itty Ipe, B.; Bawendi, M. G.; Frangioni, J. V. Renal clearance of quantum dots. Nat Biotech 2007, 25, (10), 1165-1170.

86. Owens, D. E.; Peppas, N. A. Opsonization, biodistribution, and pharmacokinetics of polymeric nanoparticles. International Journal of Pharmaceutics 2006, 307, (1), 93-102.

87. Iyer, A. K.; Khaled, G.; Fang, J.; Maeda, H. Exploiting the enhanced permeability and retention effect for tumor targeting. Drug Discovery Today 2006, 11, (17-18), 812-818.

88. Maeda, H., The enhanced permeability and retention (EPR) effect in tumor vasculature: The key role of tumor-selective macromolecular drug targeting. In Advances in Enzyme Regulation, Vol 41, Weber, G., Ed. 2001; Vol. 41, pp 189-207.

89. Fang, J.; Nakamura, H.; Maeda, H. The EPR effect: Unique features of tumor blood vessels for drug delivery, factors involved, and limitations and augmentation of the effect. Advanced drug delivery reviews 2011, 63, (3), 136-151.

Page 176: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

161

90. Torchilin, V. Tumor delivery of macromolecular drugs based on the EPR effect. Advanced drug delivery reviews 2011, 63, (3), 131-135.

91. Oshinski, J. N.; Ku, D. N.; Mukundan, S., Jr.; Loth, F.; Pettigrew, R. I. Determination of wall shear stress in the aorta with the use of MR phase velocity mapping. Journal of magnetic resonance imaging : JMRI 1995, 5, (6), 640-7.

92. Koutsiaris, A. G.; Tachmitzi, S. V.; Batis, N.; Kotoula, M. G.; Karabatsas, C. H.; Tsironi, E.; Chatzoulis, D. Z. Volume flow and wall shear stress quantification in the human conjunctival capillaries and post-capillary venules in vivo. Biorheology 2007, 44, (5-6), 375-386.

93. Koutsiaris, A. G.; Tachmitzi, S. V.; Batis, N. Wall shear stress quantification in the human conjunctival pre-capillary arterioles in vivo. Microvascular Research 2013, 85, 34-39.

94. Suo, J.; Ferrara, D. E.; Sorescu, D.; Guldberg, R. E.; Taylor, W. R.; Giddens, D. P. Hemodynamic shear stresses in mouse aortas - Implications for atherogenesis. Arterioscler. Thromb. Vasc. Biol. 2007, 27, (2), 346-351.

95. Cabral, H.; Matsumoto, Y.; Mizuno, K.; Chen, Q.; Murakami, M.; Kimura, M.; Terada, Y.; Kano, M. R.; Miyazono, K.; Uesaka, M.; Nishiyama, N.; Kataoka, K. Accumulation of sub-100 nm polymeric micelles in poorly permeable tumours depends on size. Nature Nanotechnology 2011, 6, (12), 815-823.

96. Torchilin, V. P.; Lukyanov, A. N.; Gao, Z. G.; Papahadjopoulos-Sternberg, B. Immunomicelles: Targeted pharmaceutical carriers for poorly soluble drugs. Proceedings of the National Academy of Sciences of the United States of America 2003, 100, (10), 6039-6044.

97. Dreher, M. R.; Liu, W. G.; Michelich, C. R.; Dewhirst, M. W.; Yuan, F.; Chilkoti, A. Tumor vascular permeability, accumulation, and penetration of macromolecular drug carriers. J. Natl. Cancer Inst. 2006, 98, (5), 335-344.

98. Chithrani, B. D.; Ghazani, A. A.; Chan, W. C. W. Determining the Size and Shape Dependence of Gold Nanoparticle Uptake into Mammalian Cells. Nano letters 2006, 6, (4), 662-668.

99. Champion, J. A.; Mitragotri, S. Shape Induced Inhibition of Phagocytosis of Polymer Particles. Pharmaceutical Research 2009, 26, (1), 244-249.

100. Chauhan, V. P.; Popovic, Z.; Chen, O.; Cui, J.; Fukumura, D.; Bawendi, M. G.; Jain, R. K. Fluorescent Nanorods and Nanospheres for Real-Time In Vivo

Page 177: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

162

Probing of Nanoparticle Shape-Dependent Tumor Penetration. Angewandte Chemie-International Edition 2011, 50, (48), 11417-11420.

101. Li, S.-D.; Huang, L. Pharmacokinetics and Biodistribution of Nanoparticles. Molecular pharmaceutics 2008, 5, (4), 496-504.

102. Levchenko, T. S.; Rammohan, R.; Lukyanov, A. N.; Whiteman, K. R.; Torchilin, V. P. Liposome clearance in mice: the effect of a separate and combined presence of surface charge and polymer coating. International Journal of Pharmaceutics 2002, 240, (1–2), 95-102.

103. He, C.; Hu, Y.; Yin, L.; Tang, C.; Yin, C. Effects of particle size and surface charge on cellular uptake and biodistribution of polymeric nanoparticles. Biomaterials 2010, 31, (13), 3657-3666.

104. Xiao, K.; Li, Y.; Luo, J.; Lee, J. S.; Xiao, W.; Gonik, A. M.; Agarwal, R. G.; Lam, K. S. The effect of surface charge on in vivo biodistribution of PEG-oligocholic acid based micellar nanoparticles. Biomaterials 2011, 32, (13), 3435-3446.

105. Aggarwal, P.; Hall, J. B.; McLeland, C. B.; Dobrovolskaia, M. A.; McNeil, S. E. Nanoparticle interaction with plasma proteins as it relates to particle biodistribution, biocompatibility and therapeutic efficacy. Advanced drug delivery reviews 2009, 61, (6), 428-437.

106. Stylianopoulos, T.; Poh, M.-Z.; Insin, N.; Bawendi, M. G.; Fukumura, D.; Munn, Lance L.; Jain, R. K. Diffusion of Particles in the Extracellular Matrix: The Effect of Repulsive Electrostatic Interactions. Biophysical Journal 2010, 99, (5), 1342-1349.

107. Judge, A.; McClintock, K.; Phelps, J. R.; MacLachlan, I. Hypersensitivity and loss of disease site targeting caused by antibody responses to PEGylated liposomes. Molecular Therapy 2006, 13, (2), 328-337.

108. Chanan-Khan, A.; Szebeni, J.; Savay, S.; Liebes, L.; Rafique, N. M.; Alving, C. R.; Muggia, F. M. Complement activation following first exposure to pegylated liposomal doxorubicin (Doxil): possible role in hypersensitivity reactions. Annals of Oncology 2003, 14, (9), 1430-1437.

109. Li, S.-D.; Huang, L. Stealth nanoparticles: High density but sheddable PEG is a key for tumor targeting. J. Control. Release 2010, 145, (3), 178-181.

Page 178: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

163

110. Barz, M.; Luxenhofer, R.; Zentel, R.; Vicent, M. J. Overcoming the PEG-addiction: well-defined alternatives to PEG, from structure-property relationships to better defined therapeutics. Polymer Chemistry 2011, 2, (9), 1900-1918.

111. Koshkaryev, A.; Sawant, R.; Deshpande, M.; Torchilin, V. Immunoconjugates and long circulating systems: Origins, current state of the art and future directions. Advanced drug delivery reviews 2013, 65, (1), 24-35.

112. Kirpotin, D. B.; Drummond, D. C.; Shao, Y.; Shalaby, M. R.; Hong, K.; Nielsen, U. B.; Marks, J. D.; Benz, C. C.; Park, J. W. Antibody targeting of long-circulating lipidic nanoparticles does not increase tumor localization but does increase internalization in animal models. Cancer Research 2006, 66, (13), 6732-6740.

113. Pirollo, K. F.; Chang, E. H. Does a targeting ligand influence nanoparticle tumor localization or uptake? Trends in Biotechnology 2008, 26, (10), 552-558.

114. Kamaly, N.; Xiao, Z.; Valencia, P. M.; Radovic-Moreno, A. F.; Farokhzad, O. C. Targeted polymeric therapeutic nanoparticles: design, development and clinical translation. Chemical Society reviews 2012, 41, (7), 2971-3010.

115. Cheng, Z.; Al Zaki, A.; Hui, J. Z.; Muzykantov, V. R.; Tsourkas, A. Multifunctional Nanoparticles: Cost Versus Benefit of Adding Targeting and Imaging Capabilities. Science 2012, 338, (6109), 903-910.

116. Sharifi, S.; Behzadi, S.; Laurent, S.; Laird Forrest, M.; Stroeve, P.; Mahmoudi, M. Toxicity of nanomaterials. Chemical Society reviews 2012, 41, (6), 2323-2343.

117. Peynshaert, K.; Manshian, B. B.; Joris, F.; Braeckmans, K.; De Smedt, S. C.; Demeester, J.; Soenen, S. J. Exploiting Intrinsic Nanoparticle Toxicity: The Pros and Cons of Nanoparticle-Induced Autophagy in Biomedical Research. Chemical Reviews 2014, 114, (15), 7581-7609.

118. Harper, S.; Usenko, C.; Hutchison, J. E.; Maddux, B. L. S.; Tanguay, R. L. In vivo biodistribution and toxicity depends on nanomaterial composition, size, surface functionalisation and route of exposure. Journal of Experimental Nanoscience 2008, 3, (3), 195-206.

119. Jaffer, F. A.; Weissleder, R. Molecular imaging in the clinical arena. JAMA-J. Am. Med. Assoc. 2005, 293, (7), 855-862.

Page 179: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

164

120. Frangioni, J. V. New technologies for human cancer imaging. J. Clin. Oncol. 2008, 26, (24), 4012-4021.

121. Tanaka, E.; Choi, H. S.; Fujii, H.; Bawendi, M. G.; Frangioni, J. V. Image-guided oncologic surgery using invisible light: Completed pre-clinical development for sentinel lymph node mapping. Annals of Surgical Oncology 2006, 13, (12), 1671-1681.

122. van Dam, G. M.; Themelis, G.; Crane, L. M. A.; Harlaar, N. J.; Pleijhuis, R. G.; Kelder, W.; Sarantopoulos, A.; de Jong, J. S.; Arts, H. J. G.; van der Zee, A. G. J.; Bart, J.; Low, P. S.; Ntziachristos, V. Intraoperative tumor-specific fluorescence imaging in ovarian cancer by folate receptor-alpha targeting: first in-human results. Nature medicine 2011, 17, (10), 1315-U202.

123. Bushberg, J. T.; Seibert, J. A.; Leidholdt, E. M. J.; Boone, J. M., The Essential Physics of Medical Imaging. 2nd ed.; Lippincott Williams & Wilkins: Philadelphia, PA, 2002.

124. Bleyer, A.; Welch, H. G. Effect of Three Decades of Screening Mammography on Breast-Cancer Incidence. N. Engl. J. Med. 2012, 367, (21), 1998-2005.

125. Kalager, M.; Zelen, M.; Langmark, F.; Adami, H. O. Effect of Screening Mammography on Breast-Cancer Mortality in Norway. N. Engl. J. Med. 2010, 363, (13), 1203-1210.

126. Boone, J. M.; Lindfors, K. K. Breast CT: potential for breast cancer screening and diagnosis. Future oncology (London, England) 2006, 2, (3), 351-6.

127. Boone, J. M.; Kwan, A. L. C.; Yang, K.; Burkett, G. W.; Lindfors, K. K.; Nelson, T. R. Computed tomography for imaging the breast. J. Mammary Gland Biol. Neoplasia 2006, 11, (2), 103-111.

128. Cotton, P. B.; Durkalski, V. L.; Benoit, P. C.; Palesch, Y. Y.; Mauldin, P. D.; Hoffman, B.; Vining, D. J.; Small, W. C.; Affronti, J.; Rex, D.; Kopecky, K. K.; Ackerman, S.; Burdick, J. S.; Brewington, C.; Turner, M. A.; Zfass, A.; Wright, A. R.; Iyer, R. B.; Lynch, P.; Sivak, M. V.; Butler, H. Computed tomographic colonography (virtual colonoscopy) - A multicenter comparison with standard colonoscopy for detection of colorectal neoplasia. JAMA-J. Am. Med. Assoc. 2004, 291, (14), 1713-1719.

129. Pickhardt, P. J.; Hassan, C.; Halligan, S.; Marmo, R. Colorectal Cancer: CT Colonography and Colonoscopy for Detection-Systematic Review and Meta-Analysis. Radiology 2011, 259, (2), 393-405.

Page 180: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

165

130. Gambhir, S. S. Molecular imaging of cancer with positron emission tomography. Nat. Rev. Cancer 2002, 2, (9), 683-693.

131. Kubota, R.; Yamada, S.; Kubota, K.; Ishiwata, K.; Tamahashi, N.; Ido, T. Intratumoral distribution of fluorine-18-fluorodeoxyglucose in vivo- high accumulation in macrophages and granulation tissues studied by microautoradiography. Journal of Nuclear Medicine 1992, 33, (11), 1972-1980.

132. Weissleder, R.; Pittet, M. J. Imaging in the era of molecular oncology. Nature 2008, 452, (7187), 580-589.

133. Juweid, M. E.; Cheson, B. D. Current concepts - Positron-emission tomography and assessment of cancer therapy. N. Engl. J. Med. 2006, 354, (5), 496-507.

134. Blodgett, T. M.; Meltzer, C. C.; Townsend, D. W. PET/CT: Form and function. Radiology 2007, 242, (2), 360-385.

135. O'Connor, M. K.; Kemp, B. J. Single-photon emission computed tomography/computed tomography: Basic instrumentation and innovations. Semin. Nucl. Med. 2006, 36, (4), 258-266.

136. Gore, J. C.; Manning, H. C.; Quarles, C. C.; Waddell, K. W.; Yankeelov, T. E. Magnetic resonance in the era of molecular imaging of cancer. Magn. Reson. Imaging 2011, 29, (5), 587-600.

137. O'Connor, J. P. B.; Jackson, A.; Parker, G. J. M.; Jayson, G. C. DCE-MRI biomarkers in the clinical evaluation of antiangiogenic and vascular disrupting agents. British journal of cancer 2007, 96, (2), 189-195.

138. Moffat, B. A.; Chenevert, T. L.; Lawrence, T. S.; Meyer, C. R.; Johnson, T. D.; Dong, Q.; Tsien, C.; Mukherji, S.; Quint, D. J.; Gebarski, S. S.; Robertson, P. L.; Junck, L. R.; Rehemtulla, A.; Ross, B. D. Functional diffusion map: A noninvasive MRI biomarker for early stratification of clinical brain tumor response. Proceedings of the National Academy of Sciences of the United States of America 2005, 102, (15), 5524-5529.

139. Houssami, N.; Ciatto, S.; Macaskill, P.; Lord, S. J.; Warren, R. M.; Dixon, J. M.; Irwig, L. Accuracy and surgical impact of magnetic resonance imaging in breast cancer staging: Systematic review and meta-analysis in detection of multifocal and multicentric cancer. J. Clin. Oncol. 2008, 26, (19), 3248-3258.

Page 181: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

166

140. Houssami, N.; Hayes, D. F. Review of Preoperative Magnetic Resonance Imaging (MRI) in Breast Cancer Should MRI Be Performed on All Women with Newly Diagnosed, Early Stage Breast Cancer? Ca-a Cancer Journal for Clinicians 2009, 59, (5), 290-302.

141. Kurhanewicz, J.; Vigneron, D.; Carroll, P.; Coakley, F. Multiparametric magnetic resonance imaging in prostate cancer: present and future. Curr. Opin. Urol. 2008, 18, (1), 71-77.

142. Sciarra, A.; Barentsz, J.; Bjartell, A.; Eastham, J.; Hricak, H.; Panebianco, V.; Witjes, J. A. Advances in Magnetic Resonance Imaging: How They Are Changing the Management of Prostate Cancer. European Urology 2011, 59, (6), 962-977.

143. Giannarini, G.; Petralia, G.; Thoeny, H. C. Potential and Limitations of Diffusion-Weighted Magnetic Resonance Imaging in Kidney, Prostate, and Bladder Cancer Including Pelvic Lymph Node Staging: A Critical Analysis of the Literature. European Urology 2012, 61, (2), 326-340.

144. Hirota, W. K.; Zuckerman, M. J.; Adler, D. G.; Davila, R. E.; Egan, J.; Leighton, J. A.; Qureshi, W. A.; Rajan, E.; Fanelli, R.; Wheeler-Harbaugh, J.; Baron, T. H.; Faigel, D. O.; Standards Practice, C. ASGE guideline: the role of endoscopy in the surveillance of premalignant conditions of the upper GI tract. Gastrointest. Endosc. 2006, 63, (4), 570-580.

145. Sidhu, R.; Sanders, D. S.; Morris, A. J.; McAlindon, M. E. Guidelines on small bowel enteroscopy and capsule endoscopy in adults. Gut 2008, 57, (1), 125-136.

146. Zysk, A. M.; Nguyen, F. T.; Oldenburg, A. L.; Marks, D. L.; Boppart, S. A. Optical coherence tomography: a review of clinical development from bench to bedside. Journal of biomedical optics 2007, 12, (5), 21.

147. Siphanto, R. I.; Thumma, K. K.; Kolkman, R. G. M.; van Leeuwen, T. G.; de Mul, F. F. M.; van Neck, J. W.; van Adrichem, L. N. A.; Steenbergen, W. Serial noninvasive photoacoustic imaging of neovascularization in tumor angiogenesis. Opt. Express 2005, 13, (1), 89-95.

148. Wang, L. V. Prospects of photoacoustic tomography. Med. Phys. 2008, 35, (12), 5758-5767.

149. Haka, A. S.; Shafer-Peltier, K. E.; Fitzmaurice, M.; Crowe, J.; Dasari, R. R.; Feld, M. S. Diagnosing breast cancer by using Raman spectroscopy.

Page 182: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

167

Proceedings of the National Academy of Sciences of the United States of America 2005, 102, (35), 12371-12376.

150. Haka, A. S.; Volynskaya, Z.; Gardecki, J. A.; Nazemi, J.; Shenk, R.; Wang, N.; Dasari, R. R.; Fitzmaurice, M.; Feld, M. S. Diagnosing breast cancer using Raman spectroscopy: prospective analysis. Journal of biomedical optics 2009, 14, (5).

151. Lovrics, P. J.; Cornacchi, S. D.; Vora, R.; Goldsmith, C. H.; Kahnamoui, K. Systematic review of radioguided surgery for non-palpable breast cancer. Ejso 2011, 37, (5), 388-397.

152. van der Ploeg, I. M. C.; Hobbelink, M.; van den Bosch, M. A. A. J.; Mali, W. P. T. M.; Rinkes, I. H. M. B.; van Hillegersberg, R. 'Radioguided occult lesion localisation' (ROLL) for non-palpable breast lesions: A review of the relevant literature. Ejso 2008, 34, (1), 1-5.

153. Schnabel, F.; Boolbol, S. K.; Gittleman, M.; Karni, T.; Tafra, L.; Feldman, S.; Police, A.; Friedman, N. B.; Karlan, S.; Holmes, D.; Willey, S. C.; Carmon, M.; Fernandez, K.; Akbari, S.; Harness, J.; Guerra, L.; Frazier, T.; Lane, K.; Simmons, R. M.; Estabrook, A.; Allweis, T. A Randomized Prospective Study of Lumpectomy Margin Assessment with Use of MarginProbe in Patients with Nonpalpable Breast Malignancies. Annals of Surgical Oncology 2014, 21, (5), 1589-1595.

154. Thill, M.; Dittmer, C.; Baumann, K.; Friedrichs, K.; Blohmer, J.-U. MarginProbe® – Final results of the German post-market study in breast conserving surgery of ductal carcinoma in situ. The Breast 2014, 23, (1), 94-96.

155. George E. Moore; William T. Peyton; Lyle A. French; Walter W. Walker. The Clinical Use of Fluorescein in Neurosurgery. Journal of Neurosurgery 1948, 5, (4), 392-398.

156. DeSantis, C. E.; Lin, C. C.; Mariotto, A. B.; Siegel, R. L.; Stein, K. D.; Kramer, J. L.; Alteri, R.; Robbins, A. S.; Jemal, A. Cancer Treatment and Survivorship Statistics, 2014. Ca-a Cancer Journal for Clinicians 2014, 64, (4), 252-271.

157. Karanjia, N. D.; Lordan, J. T.; Fawcett, W. J.; Quiney, N.; Worthington, T. R. Survival and recurrence after neo-adjuvant chemotherapy and liver resection for colorectal metastases - A ten year study. Ejso 2009, 35, (8), 838-843.

158. Meric, F.; Mirza, N. Q.; Vlastos, G.; Buchholz, T. A.; Kuerer, H. M.; Babiera, G. V.; Singletary, S. E.; Ross, M. I.; Ames, F. C.; Feig, B. W.;

Page 183: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

168

Krishnamurthy, S.; Perkins, G. H.; McNeese, M. D.; Strom, E. A.; Valero, V.; Hunt, K. K. Positive surgical margins and ipsilateral breast tumor recurrence predict disease-specific survival after breast-conserving therapy. Cancer 2003, 97, (4), 926-933.

159. Wapnir, I. L.; Anderson, S. J.; Mamounas, E. P.; Geyer, C. E.; Jeong, J. H.; Tan-Chiu, E.; Fisher, B.; Wolmark, N. Prognosis after ipsilateral breast tumor recurrence and locoregional recurrences in five national surgical adjuvant breast and bowel project node-positive adjuvant breast cancer trials. J. Clin. Oncol. 2006, 24, (13), 2028-2037.

160. Pleijhuis, R. G.; Graafland, M.; de Vries, J.; Bart, J.; de Jong, J. S.; van Dam, G. M. Obtaining Adequate Surgical Margins in Breast-Conserving Therapy for Patients with Early-Stage Breast Cancer: Current Modalities and Future Directions. Annals of Surgical Oncology 2009, 16, (10), 2717-2730.

161. Abdalla, E. K.; Vauthey, J. N.; Ellis, L. M.; Ellis, V.; Pollock, R.; Broglio, K. R.; Hess, K.; Curley, S. A. Recurrence and outcomes following hepatic resection, radiofrequency ablation, and combined resection/ablation for colorectal liver metastases. Ann. Surg. 2004, 239, (6), 818-824.

162. Pawlik, T. M.; Scoggins, C. R.; Zorzi, D.; Abdalla, E. K.; Andres, A.; Eng, C.; Curley, S. A.; Loyer, E. M.; Muratore, A.; Mentha, G.; Capussotti, L.; Vauthey, J. N. Effect of surgical margin status on survival and site of recurrence after hepatic resection for colorectal metastases. Ann. Surg. 2005, 241, (5), 715-724.

163. Blazer, D. G.; Kishi, Y.; Maru, D. M.; Kopetz, S.; Chun, Y. S.; Overman, M. J.; Fogelman, D.; Eng, C.; Chang, D. Z.; Wang, H.; Zorzi, D.; Ribero, D.; Ellis, L. M.; Glover, K. Y.; Wolff, R. A.; Curley, S. A.; Abdalla, E. K.; Vauthey, J. N. Pathologic Response to Preoperative Chemotherapy: A New Outcome End Point After Resection of Hepatic Colorectal Metastases. J. Clin. Oncol. 2008, 26, (33), 5344-5351.

164. Nikfarjam, M.; Shereef, S.; Kimchi, E. T.; Gusani, N. J.; Jiang, Y. X.; Avella, D. M.; Mahraj, R. P.; Staveley-O'Carroll, K. F. Survival Outcomes of Patients with Colorectal Liver Metastases Following Hepatic Resection or Ablation in the Era of Effective Chemotherapy. Annals of Surgical Oncology 2009, 16, (7), 1860-1867.

165. Yossepowitch, O.; Bjartell, A.; Eastham, J. A.; Graefen, M.; Guillonneau, B. D.; Karakiewicz, P. I.; Montironi, R.; Montorsi, F. Positive Surgical Margins in Radical Prostatectomy: Outlining the Problem and Its Long-Term Consequences. European Urology 2009, 55, (1), 87-99.

Page 184: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

169

166. Karakiewicz, P. I.; Eastham, J. A.; Graefen, M.; Cagiannos, I.; Stricker, P. D.; Klein, E.; Cangiano, T.; Schroder, F. H.; Scardino, P. T.; Kattan, M. W. Prognostic impact of positive surgical margins in surgically treated prostate cancer: Multi-institutional assessment of 5831 patients. Urology 2005, 66, (6), 1245-1250.

167. Stephenson, A. J.; Wood, D. P.; Kattan, M. W.; Klein, E. A.; Scardino, P. T.; Eastham, J. A.; Carver, B. S. Location, Extent and Number of Positive Surgical Margins Do Not Improve Accuracy of Predicting Prostate Cancer Recurrence After Radical Prostatectomy. Journal of Urology 2009, 182, (4), 1357-1363.

168. Thorek, D. L.; Robertson, R.; Bacchus, W. A.; Hahn, J.; Rothberg, J.; Beattie, B. J.; Grimm, J. Cerenkov imaging-a new modality for molecular imaging. American journal of nuclear medicine and molecular imaging 2012, 2, (2), 163.

169. Rosenthal, E. L.; Warram, J. M.; Bland, K. I.; Zinn, K. R. The Status of Contemporary Image-Guided Modalities in Oncologic Surgery. Ann. Surg. 2015, 261, (1), 46-55.

170. Handgraaf, H. J. M.; Verbeek, F. P. R.; Tummers, Q. R. J. G.; Boogerd, L. S. F.; van de Velde, C. J. H.; Vahrmeijer, A. L.; Gaarenstroom, K. N. Real-time near-infrared fluorescence guided surgery in gynecologic oncology: A review of the current state of the art. Gynecologic Oncology 2014, 135, (3), 606-613.

171. Schaafsma, B. E.; Mieog, J. S. D.; Hutteman, M.; Van der Vorst, J. R.; Kuppen, P. J. K.; Lowik, C.; Frangioni, J. V.; Van de Velde, C. J. H.; Vahrmeijer, A. L. The Clinical Use of Indocyanine Green as a Near-Infrared Fluorescent Contrast Agent for Image-Guided Oncologic Surgery. J. Surg. Oncol. 2011, 104, (3), 323-332.

172. Lakowicz, J. R., Principles of Fluorescence Spectroscopy. 3rd ed.; Springer: New York, NY, 2006.

173. Richards-Kortum, R.; Sevick-Muraca, E. Quantitative optical spectroscopy for tissue diagnosis. Annual Review of Physical Chemistry 1996, 47, 555-606.

174. Hilderbrand, S. A.; Weissleder, R. Near-infrared fluorescence: application to in vivo molecular imaging. Current Opinion in Chemical Biology 2010, 14, (1), 71-79.

175. Matsui, A.; Tanaka, E.; Choi, H. S.; Winer, J. H.; Kianzad, V.; Gioux, S.; Laurence, R. G.; Frangioni, J. V. Real-time intra-operative near-infrared

Page 185: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

170

fluorescence identification of the extrahepatic bile ducts using clinically available contrast agents. Surgery 2010, 148, (1), 87-95.

176. Gioux, S.; Hak Soo, C.; Frangioni, J. V. Image-Guided Surgery Using Invisible Near-Infrared Light: Fundamentals of Clinical Translation. Molecular Imaging 2010, 9, (5), 237-255.

177. Hojo, T.; Nagao, T.; Kikuyama, M.; Akashi, S.; Kinoshita, T. Evaluation of sentinel node biopsy by combined fluorescent and dye method and lymph flow for breast cancer. Breast 2010, 19, (3), 210-213.

178. Gilmore, D.; Khullar, O.; Gioux, S.; Stockdale, A.; Frangioni, J.; Colson, Y.; Russell, S. Effective Low-dose Escalation of Indocyanine Green for Near-infrared Fluorescent Sentinel Lymph Node Mapping in Melanoma. Annals of Surgical Oncology 2013, 20, (7), 2357-2363.

179. Yuasa, Y.; Seike, J.; Yoshida, T.; Takechi, H.; Yamai, H.; Yamamoto, Y.; Furukita, Y.; Goto, M.; Minato, T.; Nishino, T.; Inoue, S.; Fujiwara, S.; Tangoku, A. Sentinel Lymph Node Biopsy Using Intraoperative Indocyanine Green Fluorescence Imaging Navigated with Preoperative CT Lymphography for Superficial Esophageal Cancer. Annals of Surgical Oncology 2012, 19, (2), 486-493.

180. Jung, S. Y.; Kim, S. K.; Kim, S. W.; Kwon, Y.; Lee, E. S.; Kang, H. S.; Ko, K. L.; Shin, K. H.; Lee, K. S.; Park, I. H.; Ro, J.; Jeong, H. J.; Joo, J.; Kang, S. H.; Lee, S. Comparison of Sentinel Lymph Node Biopsy Guided by the Multimodal Method of Indocyanine Green Fluorescence, Radioisotope, and Blue Dye Versus the Radioisotope Method in Breast Cancer: A Randomized Controlled Trial. Annals of Surgical Oncology 2014, 21, (4), 1254-1259.

181. Intes, X.; Ripoll, J.; Chen, Y.; Nioka, S.; Yodh, A. G.; Chance, B. In vivo continuous-wave optical breast imaging enhanced with Indocyanine Green. Med. Phys. 2003, 30, (6), 1039-1047.

182. Ntziachristos, V.; Yodh, A. G.; Schnall, M.; Chance, B. Concurrent MRI and diffuse optical tomography of breast after indocyanine green enhancement. Proceedings of the National Academy of Sciences of the United States of America 2000, 97, (6), 2767-2772.

183. Alacam, B.; Yazici, B.; Intes, X.; Nioka, S.; Chance, B. Pharmacokinetic-rate images of indocyanine green for breast tumors using near-infrared optical methods. Physics in Medicine and Biology 2008, 53, (4), 837-859.

Page 186: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

171

184. Poellinger, A.; Burock, S.; Grosenick, D.; Hagen, A.; Ludemann, L.; Diekmann, F.; Engelken, F.; Macdonald, R.; Rinneberg, H.; Schlag, P. M. Breast Cancer: Early- and Late-Fluorescence Near-Infrared Imaging with Indocyanine Green-A Preliminary Study. Radiology 2011, 258, (2), 409-416.

185. Gotoh, K.; Yamada, T.; Ishikawa, O.; Takahashi, H.; Eguchi, H.; Yano, M.; Ohigashi, H.; Tomita, Y.; Miyamoto, Y.; Imaoka, S. A novel image-guided surgery of hepatocellular carcinoma by indocyanine green fluorescence imaging navigation. J. Surg. Oncol. 2009, 100, (1), 75-79.

186. Uchiyama, K.; Ueno, M.; Ozawa, S.; Kiriyama, S.; Shigekawa, Y.; Yamaue, H. Combined Use of Contrast-Enhanced Intraoperative Ultrasonography and a Fluorescence Navigation System for Identifying Hepatic Metastases. World J.Surg. 2010, 34, (12), 2953-2959.

187. Ishizawa, T.; Fukushima, N.; Shibahara, J.; Masuda, K.; Tamura, S.; Aoki, T.; Hasegawa, K.; Beck, Y.; Fukayama, M.; Kokudo, N. Real-Time Identification of Liver Cancers by Using Indocyanine Green Fluorescent Imaging. Cancer 2009, 115, (11), 2491-2504.

188. Ishizawa, T.; Masuda, K.; Urano, Y.; Kawaguchi, Y.; Satou, S.; Kaneko, J.; Hasegawa, K.; Shibahara, J.; Fukayama, M.; Tsuji, S.; Midorikawa, Y.; Aburatani, H.; Kokudo, N. Mechanistic Background and Clinical Applications of Indocyanine Green Fluorescence Imaging of Hepatocellular Carcinoma. Annals of Surgical Oncology 2014, 21, (2), 440-448.

189. Hojo, M.; Arakawa, Y.; Funaki, T.; Yoshida, K.; Kikuchi, T.; Takagi, Y.; Araki, Y.; Ishii, A.; Kunieda, T.; Takahashi, J. C.; Miyamoto, S. Usefulness of Tumor Blood Flow Imaging by Intraoperative Indocyanine Green Videoangiography in Hemangioblastoma Surgery. World Neurosurgery 2014, 82, (3–4), e495-e501.

190. Stummer, W.; Pichlmeier, U.; Meinel, T.; Wiestler, O. D.; Zanella, F.; Reulen, H.-J. Fluorescence-guided surgery with 5-aminolevulinic acid for resection of malignant glioma: a randomised controlled multicentre phase III trial. The Lancet Oncology 2006, 7, (5), 392-401.

191. Mohs, A. M.; Mancini, M. C.; Singhal, S.; Provenzale, J. M.; Leyland-Jones, B.; Wang, M. D.; Nie, S. Hand-held Spectroscopic Device for In Vivo and Intraoperative Tumor Detection: Contrast Enhancement, Detection Sensitivity, and Tissue Penetration. Analytical Chemistry 2010, 82, (21), 9058-9065.

192. Gioux, S.; Kianzad, V.; Ciocan, R.; Gupta, S.; Oketokoun, R.; Frangioni, J. V. High-Power, Computer-Controlled, Light-Emitting Diode-Based Light Sources

Page 187: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

172

for Fluorescence Imaging and Image-Guided Surgery. Molecular Imaging 2009, 8, (3), 156-165.

193. Menendez, J. A.; Lupu, R. Fatty acid synthase and the lipogenic phenotype in cancer pathogenesis. Nat. Rev. Cancer 2007, 7, (10), 763-777.

194. Maier, T.; Jenni, S.; Ban, N. Architecture of mammalian fatty acid synthase at 4.5 A resolution. Science 2006, 311, (5765), 1258-62.

195. Kuhajda, F. P. Fatty Acid Synthase and Cancer: New Application of an Old Pathway. Cancer research 2006, 66, (12), 5977-5980.

196. Flavin, R.; Peluso, S.; Nguyen, P. L.; Loda, M. Fatty acid synthase as a potential therapeutic target in cancer. Future oncology 2010, 6, (4), 551-62.

197. Pandey, P. R.; Liu, W.; Xing, F.; Fukuda, K.; Watabe, K. Anti-cancer drugs targeting fatty acid synthase (FAS). Recent patents on anti-cancer drug discovery 2012, 7, (2), 185-97.

198. Gatenby, R. A.; Gillies, R. J. Why do cancers have high aerobic glycolysis? Nat. Rev. Cancer 2004, 4, (11), 891-899.

199. Alli, P. M.; Pinn, M. L.; Jaffee, E. M.; McFadden, J. M.; Kuhajda, F. P. Fatty acid synthase inhibitors are chemopreventive for mammary cancer in neu-N transgenic mice. Oncogene 2005, 24, (1), 39-46.

200. Li, J. N.; Gorospe, M.; Chrest, F. J.; Kumaravel, T. S.; Evans, M. K.; Han, W. F.; Pizer, E. S. Pharmacological inhibition of fatty acid synthase activity produces both cytostatic and cytotoxic effects modulated by p53. Cancer Res 2001, 61, (4), 1493-9.

201. Lupu, R.; Menendez, J. A. Pharmacological inhibitors of fatty acid synthase (FASN)-catalyzed endogenous fatty acid biogenesis: a new family of anti-cancer agents? Current pharmaceutical biotechnology 2006.

202. Pizer, E. S.; Thupari, J.; Han, W. F.; Pinn, M. L.; Chrest, F. J.; Frehywot, G. L.; Townsend, C. A.; Kuhajda, F. P. Malonyl-coenzyme-A is a potential mediator of cytotoxicity induced by fatty-acid synthase inhibition in human breast cancer cells and xenografts. Cancer Res 2000, 60, (2), 213-8.

203. Filippatos, T. D.; Derdemezis, C. S.; Gazi, I. F.; Nakou, E. S.; Mikhailidis, D. P.; Elisaf, M. S. Orlistat-associated adverse effects and drug interactions: a

Page 188: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

173

critical review. Drug safety : an international journal of medical toxicology and drug experience 2008, 31, (1), 53-65.

204. Pemble, C. W.; Johnson, L. C.; Kridel, S. J.; Lowther, W. T. Crystal structure of the thioesterase domain of human fatty acid synthase inhibited by Orlistat. Nature Structural &#38; Molecular Biology 2007, 14, (8), 704-709.

205. Fako, V. E.; Zhang, J. T.; Liu, J. Y. Mechanism of Orlistat Hydrolysis by the Thioesterase of Human Fatty Acid Synthase. ACS catalysis 2014, 4, (10), 3444-3453.

206. Kridel, S. J.; Axelrod, F.; Rozenkrantz, N.; Smith, J. W. Orlistat is a novel inhibitor of fatty acid synthase with antitumor activity. Cancer research 2004, 64, (6), 2070-2075.

207. Browne, C. D.; Hindmarsh, E. J.; Smith, J. W. Inhibition of endothelial cell proliferation and angiogenesis by orlistat, a fatty acid synthase inhibitor. FASEB journal : official publication of the Federation of American Societies for Experimental Biology 2006, 20, (12), 2027-35.

208. Grube, S.; Dunisch, P.; Freitag, D.; Klausnitzer, M.; Sakr, Y.; Walter, J.; Kalff, R.; Ewald, C. Overexpression of fatty acid synthase in human gliomas correlates with the WHO tumor grade and inhibition with Orlistat reduces cell viability and triggers apoptosis. Journal of neuro-oncology 2014, 118, (2), 277-87.

209. Menendez, J. A. Antitumoral actions of the anti-obesity drug orlistat (XenicalTM) in breast cancer cells: blockade of cell cycle progression, promotion of apoptotic cell death and PEA3-mediated transcriptional repression of Her2/neu (erbB-2) oncogene. Annals of Oncology 2005, 16, (8), 1253-1267.

210. Chuang, H. Y.; Chang, Y. F.; Hwang, J. J. Antitumor effect of orlistat, a fatty acid synthase inhibitor, is via activation of caspase-3 on human colorectal carcinoma-bearing animal. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie 2011, 65, (4), 286-92.

211. Carvalho, M. A.; Zecchin, K. G.; Seguin, F.; Bastos, D. C.; Agostini, M.; Rangel, A. L.; Veiga, S. S.; Raposo, H. F.; Oliveira, H. C.; Loda, M.; Coletta, R. D.; Graner, E. Fatty acid synthase inhibition with Orlistat promotes apoptosis and reduces cell growth and lymph node metastasis in a mouse melanoma model. International journal of cancer. Journal international du cancer 2008, 123, (11), 2557-65.

Page 189: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

174

212. Dowling, S.; Cox, J.; Cenedella, R. J. Inhibition of fatty acid synthase by Orlistat accelerates gastric tumor cell apoptosis in culture and increases survival rates in gastric tumor bearing mice in vivo. Lipids 2009, 44, (6), 489-98.

213. Agostini, M.; Almeida, L. Y.; Bastos, D. C.; Ortega, R. M.; Moreira, F. S.; Seguin, F.; Zecchin, K. G.; Raposo, H. F.; Oliveira, H. C.; Amoedo, N. D.; Salo, T.; Coletta, R. D.; Graner, E. The fatty acid synthase inhibitor orlistat reduces the growth and metastasis of orthotopic tongue oral squamous cell carcinomas. Molecular cancer therapeutics 2014, 13, (3), 585-95.

214. Seguin, F.; Carvalho, M. A.; Bastos, D. C.; Agostini, M.; Zecchin, K. G.; Alvarez-Flores, M. P.; Chudzinski-Tavassi, A. M.; Coletta, R. D.; Graner, E. The fatty acid synthase inhibitor orlistat reduces experimental metastases and angiogenesis in B16-F10 melanomas. British journal of cancer 2012, 107, (6), 977-87.

215. Wishart, D. S.; Knox, C.; Guo, A. C.; Shrivastava, S.; Hassanali, M.; Stothard, P.; Chang, Z.; Woolsey, J. DrugBank: a comprehensive resource for in silico drug discovery and exploration. Nucleic acids research 2006, 34, (Database issue), D668-72.

216. Zhi, J.; Melia, A. T.; Funk, C.; Viger-Chougnet, A.; Hopfgartner, G.; Lausecker, B.; Wang, K.; Fulton, J. S.; Gabriel, L.; Mulligan, T. E. Metabolic profiles of minimally absorbed orlistat in obese/overweight volunteers. Journal of clinical pharmacology 1996, 36, (11), 1006-11.

217. Choi, K. Y.; Min, K. H.; Na, J. H.; Choi, K.; Kim, K.; Park, J. H.; Kwon, I. C.; Jeong, S. Y. Self-assembled hyaluronic acid nanoparticles as a potential drug carrier for cancer therapy: synthesis, characterization, and in vivo biodistribution. Journal of Materials Chemistry 2009, 19, (24), 4102.

218. Liu, Y.; Sun, J.; Cao, W.; Yang, J.; Lian, H.; Li, X.; Sun, Y.; Wang, Y.; Wang, S.; He, Z. Dual targeting folate-conjugated hyaluronic acid polymeric micelles for paclitaxel delivery. Int J Pharm 2011, 421, (1), 160-9.

219. Mishra, A.; Mishra, A.; Behera, R. K.; Behera, R. K.; Behera, P. K.; Behera, P. K.; Mishra, B. K.; Mishra, B. K.; Behera, G. B.; Behera, G. B. Cyanines during the 1990s: A Review. Chem. Rev 2000, 100, (6), 1973-2012.

220. Saxena, V.; Sadoqi, M.; Shao, J. Indocyanine green-loaded biodegradable nanoparticles: preparation, physicochemical characterization and in vitro release. Int J Pharm 2004, 278, (2), 293-301.

Page 190: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

175

221. Yoon, H. K.; Ray, A.; Lee, Y. E.; Kim, G.; Wang, X.; Kopelman, R. Polymer-Protein Hydrogel Nanomatrix for Stabilization of Indocyanine Green towards Targeted Fluorescence and Photoacoustic Bio-imaging. Journal of materials chemistry. B, Materials for biology and medicine 2013, 1, (41).

222. Ganesh, S.; Iyer, A. K.; Gattacceca, F.; Morrissey, D. V.; Amiji, M. M. In vivo biodistribution of siRNA and cisplatin administered using CD44-targeted hyaluronic acid nanoparticles. Journal of controlled release : official journal of the Controlled Release Society 2013, 172, (3), 699-706.

223. Yaseen, M. A.; Yu, J.; Jung, B.; Wong, M. S.; Anvari, B. Biodistribution of encapsulated indocyanine green in healthy mice. Mol Pharm 2009, 6, (5), 1321-32.

224. Yu, J.; Yaseen, M. A.; Anvari, B.; Wong, M. S. Synthesis of near-infrared-absorbing nanoparticle-assembled capsules. Chemistry of Materials 2007, 19, (6), 1277-1284.

225. Saxena, V.; Sadoqi, M.; Shao, J. Enhanced photo-stability, thermal-stability and aqueous-stability of indocyanine green in polymeric nanoparticulate systems. Journal of photochemistry and photobiology B, Biology 2004, 74, (1), 29-38.

226. Zheng, C.; Zheng, M.; Gong, P.; Jia, D.; Zhang, P.; Shi, B.; Sheng, Z.; Ma, Y.; Cai, L. Indocyanine green-loaded biodegradable tumor targeting nanoprobes for in vitro and in vivo imaging. Biomaterials 2012, 33, (22), 5603-9.

227. Dubois, A.; Canva, M.; Brun, A.; Chaput, F.; Boilot, J. P. Photostability of dye molecules trapped in solid matrices. Appl Opt 1996, 35, (18), 3193-9.

228. Mok, H.; Jeong, H.; Kim, S.-J.; Chung, B. H. Indocyanine green encapsulated nanogels for hyaluronidase activatable and selective near infrared imaging of tumors and lymph nodes. Chemical Communications 2012, 48, (69), 8628-8630.

229. Ogawa, M.; Kosaka, N.; Longmire, M. R.; Urano, Y.; Choyke, P. L.; Kobayashi, H. Fluorophore-quencher based activatable targeted optical probes for detecting in vivo cancer metastases. Molecular pharmaceutics 2009, 6, (2), 386-395.

230. Mohs, A. M.; Mancini, M.; Provenzale, J.; Saba, C.; Cornell, K.; Howerth, E.; Nie, S. An Integrated Widefield Imaging and Spectroscopy System for Contrast-Enhanced, Image-guided Resection of Tumors. Biomedical Engineering, IEEE Transactions on 2015, PP, (99), 1-1.

Page 191: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

176

231. De Grand, A. M.; Lomnes, S. J.; Lee, D. S.; Pietrzykowski, M.; Ohnishi, S.; Morgan, T. G.; Gogbashian, A.; Laurence, R. G.; Frangioni, J. V. Tissue-like phantoms for near-infrared fluorescence imaging system assessment and the training of surgeons. Journal of biomedical optics 2006, 11, (1), 014007.

232. Pleijhuis, R. G.; Langhout, G. C.; Helfrich, W.; Themelis, G.; Sarantopoulos, A.; Crane, L. M.; Harlaar, N. J.; de Jong, J. S.; Ntziachristos, V.; van Dam, G. M. Near-infrared fluorescence (NIRF) imaging in breast-conserving surgery: assessing intraoperative techniques in tissue-simulating breast phantoms. European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology 2011, 37, (1), 32-9.

233. Makino, A.; Kizaka-Kondoh, S.; Yamahara, R.; Hara, I.; Kanzaki, T.; Ozeki, E.; Hiraoka, M.; Kimura, S. Near-infrared fluorescence tumor imaging using nanocarrier composed of poly(L-lactic acid)-block-poly(sarcosine) amphiphilic polydepsipeptide. Biomaterials 2009, 30, (28), 5156-60.

234. Miki, K.; Oride, K.; Inoue, S.; Kuramochi, Y.; Nayak, R. R.; Matsuoka, H.; Harada, H.; Hiraoka, M.; Ohe, K. Ring-opening metathesis polymerization-based synthesis of polymeric nanoparticles for enhanced tumor imaging in vivo: Synergistic effect of folate-receptor targeting and PEGylation. Biomaterials 2010, 31, (5), 934-42.

235. Beziere, N.; Lozano, N.; Nunes, A.; Salichs, J.; Queiros, D.; Kostarelos, K.; Ntziachristos, V. Dynamic imaging of PEGylated indocyanine green (ICG) liposomes within the tumor microenvironment using multi-spectral optoacoustic tomography (MSOT). Biomaterials 2014, 37C, 415-424.

236. Marshall, M. V.; Draney, D.; Sevick-Muraca, E. M.; Olive, D. M. Single-Dose Intravenous Toxicity Study of IRDye 800CW in Sprague-Dawley Rats. Molecular Imaging and Biology 2010, 12, (6), -594.

237. Ott, P. Hepatic elimination of indocyanine green with special reference to distribution kinetics and the influence of plasma protein binding. Pharmacology & toxicology 1998, 83 Suppl 2, 1-48.

238. Miki, K.; Inoue, T.; Kobayashi, Y.; Nakano, K.; Matsuoka, H.; Yamauchi, F.; Yano, T.; Ohe, K. Near-Infrared Dye-Conjugated Amphiphilic Hyaluronic Acid Derivatives as a Dual Contrast Agent for In Vivo Optical and Photoacoustic Tumor Imaging. Biomacromolecules 2014.

239. Frangioni, J. New technologies for human cancer imaging. J Clin Oncol 2008, 26, (24), 4012-4021.

Page 192: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

177

240. Dvorak, H. F. Vascular permeability to plasma, plasma proteins, and cells: an update. Current opinion in hematology 2010, 17, (3), 225-229.

241. Laurent, T. C.; Fraser, J. R. Hyaluronan. The FASEB journal : official publication of the Federation of American Societies for Experimental Biology 1992, 6, (7), 2397-2404.

242. Misra, S.; Heldin, P.; Hascall, V. C.; Karamanos, N. K.; Skandalis, S. S.; Markwald, R. R.; Ghatak, S. Hyaluronan-CD44 interactions as potential targets for cancer therapy. FEBS Journal 2011, 278, (9), 1429-1443.

243. Platt, V. M.; Szoka, F. C., Jr. Anticancer therapeutics: targeting macromolecules and nanocarriers to hyaluronan or CD44, a hyaluronan receptor. Molecular pharmaceutics 2008, 5, (4), 474-86.

244. Sheridan, C.; Kishimoto, H.; Fuchs, R. K.; Mehrotra, S.; Bhat-Nakshatri, P.; Turner, C. H.; Goulet, R., Jr.; Badve, S.; Nakshatri, H. CD44+/CD24- breast cancer cells exhibit enhanced invasive properties: an early step necessary for metastasis. Breast cancer research : BCR 2006, 8, (5), R59.

245. Zöller, M. CD44: can a cancer-initiating cell profit from an abundantly expressed molecule? Nat. Rev. Cancer 2011, 11, (4), 254-267.

246. Bennett, P. K.; Li, Y. T.; Edom, R.; Henion, J. Quantitative determination of Orlistat (tetrahydrolipostatin, Ro 18-0647) in human plasma by high-performance liquid chromatography coupled with ion spray tandem mass spectrometry. Journal of mass spectrometry : JMS 1997, 32, (7), 739-49.

247. Souri, E.; Jalalizadeh, H.; Kebriaee-Zadeh, A.; Zadehvakili, B. HPLC analysis of orlistat and its application to drug quality control studies. Chemical & Pharmaceutical Bulletin 2007, 55, (2), 251-254.

248. Mohammadi, A.; Haririan, I.; Rezanour, N.; Ghiasi, L.; Walker, R. B. A stability-indicating high performance liquid chromatographic assay for the determination of orlistat in capsules. Journal of Chromatography A 2006, 1116, (1-2), 153-157.

249. Pemble IV, C. W.; Johnson, L. C.; Kridel, S. J.; Lowther, W. T. Crystal structure of the thioesterase domain of human fatty acid synthase inhibited by Orlistat. Nature structural & molecular biology 2007, 14, (8), 704-709.

Page 193: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

178

250. Odens, H.; Lowther, T.; Kridel, S.; Watts, L.; Filipponi, L.; Schmitt, J. Inhibition of the thioesterase activity of human fatty acid synthase by 1,4- and 9,10-diones. Chem Pharm Bull (Tokyo) 2014, 62, (9), 933-6.

251. Purohit, V. C.; Richardson, R. D.; Smith, J. W.; Romo, D. Practical, catalytic, asymmetric synthesis of beta-lactones via a sequential ketene dimerization/hydrogenation process: inhibitors of the thioesterase domain of fatty acid synthase. J Org Chem 2006, 71, (12), 4549-4558.

252. Hill, B. G.; Dranka, B. P.; Zou, L.; Chatham, J. C.; Darley-Usmar, V. M. Importance of the bioenergetic reserve capacity in response to cardiomyocyte stress induced by 4-hydroxynonenal. Biochem J 2009, 424, (1), 99-107.

253. Pallasch, C. P.; Schwamb, J.; Konigs, S.; Schulz, A.; Debey, S.; Kofler, D.; Schultze, J. L.; Hallek, M.; Ultsch, A.; Wendtner, C. M. Targeting lipid metabolism by the lipoprotein lipase inhibitor orlistat results in apoptosis of B-cell chronic lymphocytic leukemia cells. Leukemia 2008, 22, (3), 585-92.

254. Wang, A. Z.; Langer, R.; Farokhzad, O. C. Nanoparticle Delivery of Cancer Drugs. Annual Review of Medicine, Vol 63 2012, 63, 185-198.

255. Hill, T. K.; Abdulahad, A.; Kelkar, S. S.; Marini, F. C.; Long, T. E.; Provenzale, J. M.; Mohs, A. M. Indocyanine Green-Loaded Nanoparticles for Image-Guided Tumor Surgery. Bioconjugate chemistry 2015, 26, (2), 294-303.

256. Choi, K. Y.; Jeon, E. J.; Yoon, H. Y.; Lee, B. S.; Na, J. H.; Min, K. H.; Kim, S. Y.; Myung, S. J.; Lee, S.; Chen, X. Y.; Kwon, I. C.; Choi, K.; Jeong, S. Y.; Kim, K.; Park, J. H. Theranostic nanoparticles based on PEGylated hyaluronic acid for the diagnosis, therapy and monitoring of colon cancer. Biomaterials 2012, 33, (26), 6186-6193.

257. Jin, L. Q.; Hope, K. J.; Zhai, Q. L.; Smadja-Joffe, F.; Dick, J. E. Targeting of CD44 eradicates human acute myeloid leukemic stem cells. Nature medicine 2006, 12, (10), 1167-1174.

258. Konopleva, M. Y.; Jordan, C. T. Leukemia Stem Cells and Microenvironment: Biology and Therapeutic Targeting. J. Clin. Oncol. 2011, 29, (5), 591-599.

259. Casucci, M.; di Robilant, B. N.; Falcone, L.; Camisa, B.; Norelli, M.; Genovese, P.; Gentner, B.; Gullotta, F.; Ponzoni, M.; Bernardi, M.; Marcatti, M.; Saudemont, A.; Bordignon, C.; Savoldo, B.; Ciceri, F.; Naldini, L.; Dotti, G.; Bonini, C.; Bondanza, A. CD44v6-targeted T cells mediate potent antitumor

Page 194: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

179

effects against acute myeloid leukemia and multiple myeloma. Blood 2013, 122, (20), 3461-3472.

260. Belov, L.; de la Vega, O.; dos Remedios, C. G.; Mulligan, S. P.; Christopherson, R. I. Immunophenotyping of leukemias using a cluster of differentiation antibody microarray. Cancer Research 2001, 61, (11), 4483-4489.

261. Ma, Y.; Sadoqi, M.; Shao, J. Biodistribution of indocyanine green-loaded nanoparticles with surface modifications of PEG and folic acid. Int J Pharm 2012, 436, (1-2), 25-31.

262. Saxena, V.; Sadoqi, M.; Shao, J. Polymeric nanoparticulate delivery system for Indocyanine green: biodistribution in healthy mice. Int J Pharm 2006, 308, (1-2), 200-4.

263. Saxena, V.; Sadoqi, M.; Shao, J. Enhanced photo-stability, thermal-stability and aqueous-stability of indocyanine green in polymeric nanoparticulate systems. Journal of photochemistry and photobiology. B, Biology 2004, 74, (1), 29-38.

264. Yang, P. Y.; Liu, K.; Ngai, M. H.; Lear, M. J.; Wenk, M. R.; Yao, S. Q. Activity-Based Proteome Profiling of Potential Cellular Targets of Orlistat - An FDA-Approved Drug with Anti-Tumor Activities. J. Am. Chem. Soc. 2010, 132, (2), 656-666.

265. Stern, R.; Asari, A. A.; Sugahara, K. N. Hyaluronan fragments: An information-rich system. European Journal of Cell Biology 2006, 85, (8), 699-715.

Page 195: DELIVERY BY TANNER KINKADE HILL WAKE FOREST …...hyaluronic acid (HLA) as a hydrophilic polymer backbone for the synthesis of nanoscale polymeric micelles loaded with either the near

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APPENDIX

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Nature Reviews Drug Discovery

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TANNER K. HILL CURRICULUM VITAE

Virginia Tech/Wake Forest University School of Biomedical Engineering and Sciences 1440 Brookwood Dr. Winston-Salem, NC. 27106 (336) 831-4301 [email protected] [email protected] EDUCATION 2015 Ph.D., Biomedical Engineering, Virginia Tech/Wake Forest University, Winston

Salem, NC. (exp. May 2015) 2009 B.S., Biological Sciences, Magna cum Laude, Colorado State University, Ft.

Collins, CO. Minors: Biochemistry Physics, Mathematics RESEARCH EXPERIENCE 2012-2015 Graduate Student

Synthesis, characterization, in vitro and in vivo testing of polymeric hyaluronic acid nanoparticles for image guided surgery and drug delivery

Virginia Tech/Wake Forest University Principal Investigator: Aaron M. Mohs, Ph.D. 2010-2012 Graduate Student

Synthesis, characterization, in vitro and in vivo testing of electrospun collagen-poly-(caprolactone) tissue engineered vascular scaffolds for treatment of peripheral vascular disease Virginia Tech/Wake Forest University Principal Investigator: Sang Jin Lee, Ph.D.

2008-2009 Undergraduate Research Assistant

Cloning of a recombinant plasmid for the purpose of expressing H4 histone with reversed amino acid sequence in tail domain for protein-protein interaction analysis Colorado State University Principal Investigator: Jeffrey Hansen, Ph.D.

2007-2008 Undergraduate Research Assistant

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Computational modeling of predator/prey interaction in two dimensional space. Computational modeling of Los Gatos Research Methane Analyzer using Matlab Colorado State University Principal Investigator: Colleen Webb, Ph.D., Joseph von Fischer, Ph.D.

SCIENTIFIC EXPERIENCE Analytical Absorbance/fluorescence spectroscopy, dynamic light scattering, NMR,

SEC, mass spec analysis, SEM Synthetic Drug formulation chemistry, nanoparticle self-assembly, organic synthesis

and purification, bioconjugation, electrospinning Biological Mammalian cell culture, cytotoxicity assays, histology, fluorescence and

light microscopy, flow cytometry, bioreactor conditioning, Southern/Western blots, PCR

Translational Design of experiments, data and statistical analysis, novel assay design

and implementation, image guided surgery, small and large animal surgery, small animal tumor models, stress/strain testing, bioreactor design, detailed record keeping

SCHOLARSHIPS AND AWARDS 2014-2015 Mike and Lucy Robbins Fellowship Award Winner, Wake Forest

University Graduate School of the Arts and Sciences 2010-2014 Graduate Research Assistant, Virginia Tech/Wake Forest University

School for Biomedical Engineering, Summer 2008-2009 FEScUE Undergraduate Computational Modeling Fellowship, Colorado

State University 2007-2008 First Year Undergraduate Physics Scholarship, Colorado State University 2006-2007 Colorado State University Undergraduate Scholarship LEADERSHIP AND SERVICE 2013-2014 Biomedical Engineering Society Student Chapter President, Wake Forest

University 2013-2014 Volunteer, Wake Forest Baptist Health

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2013-2014 Volunteer, Community Care Center of Winston-Salem 2011-2015 Undergraduate and Summer Student Mentor 2010-2015 Biomedical Engineering Society Member AUTHORSHIPS AND PRESENTATIONS Journal Publications Indocyanine Green-Loaded Nanoparticles for Image Guided Tumor Surgery. Tanner K.

Hill, Asem Abdulahad, Sneha S. Kelkar, Frank C. Marini, Timothy E. Long, James M. Provenzale, Aaron M. Mohs. Bioconjugate Chemistry 2015, 26(2), 294-303. http://pubs.acs.org/doi/abs/10.1021/bc5005679

Fabrication and Characterization of Medical Grade Polyurethane Composite Catheters for Near-Infrared Imaging. Andre T. Stevenson Jr., Laura M. Reese, Tanner K. Hill, Jeffrey McGuire, Aaron M. Mohs, Raj Shekhar, Lissett R. Bickford, Abby R. Whittington. Biomaterials 2015, 54, 168-176. http://www.sciencedirect.com/science/article/pii/S0142961215002902 Oral and Poster Presentations Development of a Nanoparticle Formulation of Orlistat: Solubility, Stability, and Cytotoxicity. Tanner K. Hill, Frances B. Wheeler, Amanda L. Davis, Sneha Kelkar, Steven J. Kridel, Aaron M. Mohs. BMES Annual Meeting, poster presentation, 2014/10/24 Synthesis, Characterization, and Pre-Clinical Evaluation of Hyaluronan Based Nanoparticles for Image-Guided Surgery. Tanner K. Hill, Sneha Kelkar, Frank C. Marini, Edward A. Levine, James M. Provenzale, Aaron M. Mohs. Annual SBES Symposium, poster presentation, 2014/5/15 Synthesis, Characterization, and Pre-Clinical Evaluation of Hyaluronan Based Nanoparticles for Image Guided Surgery. Tanner K. Hill, Sneha Kelkar, Frank C. Marini, Edward A. Levine, James M. Provenzale, Aaron M. Mohs. 2014 Duke University Fitzpatrick Institute for Photonics Annual Symposium. Poster presentation, 2014/3/11 Near Infrared Fluorescent Polysaccharide-Based Nanoparticles for Image-Guided Tumor Surgery. Tanner K. Hill, Sneha Kelkar PhD, Frank C. Marini PhD, Aaron M. Mohs, PhD. 2013 NCI Alliance for Nanotechnology in Cancer Annual Principal Investigators Meeting. Podium presentation, 2013/9/19 Development of Hyaluronan-Based Nanoparticles for Intraoperative Breast Cancer Imaging. Tanner K. Hill, Sneha Kelkar, Asem Abdulahad, Timothy Long, Frank C. Marini, Aaron M. Mohs. 2013 Annual SBES Symposium. Poster presentation, 2013/5/16

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Near Infrared Image Guided Tumor Removal: Epidermal Growth Factor as a Target. Tanner K. Hill, Frank C. Marini, Aaron M. Mohs. 2012 BMES Annual Meeting. Podium presentation, 2012/10/27 An Innovative Approach to Building Clinically Relevant sized Tissues and Organs. Tanner K. Hill, Jaehyun Kim, Peter Masso, Sang Jin Lee, Karl-Erik Andersson, Anthony Atala, James J. Yoo. Poster presentation, 15th Annual Hilton Head Workshop: Regnerative Medicine, Innovations for Clinical Applications, hosted by Georgia Tech. March 18, 2011 Book Chapters Electrospun Nanofibers in Tissue Engineering. Mitchell R. Ladd, Tanner K. Hill, James J. Yoo, Sang Jin Lee. Chapter 16 of “Nanofibers – Production, Properties and Functional Applications”. ISBN 978-953-307-420-7, InTech Publishing. 2011


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