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transcript
June 25, 2014
Biomedical Technologies: Microfluidic gsystems for three-dimensional cell culture
and microenvironment
Karen C Cheung, PhDAssociate Professor
Department of Electrical and Computer EngineeringThe University of British Columbia
Vancouver, BC, Canada
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UBC ECE Research Day, Applied Materials, June 25, 2014
Biomedical Technologies: Convergence of Disciplines
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source: H. Pielartzik, Bayer MaterialScience AG, Leverkusen
UBC ECE Research Day, Applied Materials, June 25, 2014
Biomedical Microdevices (BioMEMS) fabrication
BioMEMS: in addition:Micro Electro Mechanical Systems BioMEMS: in addition:Nontraditional substrates
glass, polymers
Molding of polymers
Micro Electro Mechanical Systems(MEMS):semiconductor processing technologies Molding of polymers
hot embossing; injection moldingsoft lithography
Materials surface modification to
technologies Conventional: Thin film deposition, etching, photolithography, etc.New: Deep RIE, Thick Plating, electro Materials surface modification to
increase biocompatibilitydischarge machining, …
Form structures used in sensors and actuators
accelerometerProf. Edmond Cretu
microelectrodesProf. Ken Takahata
fiber endoscopes for in-vivo imagingProf. Shuo Tang
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UBC ECE Research Day, Applied Materials, June 25, 2014
Rapid prototyping infrastructure at UBCEmbedded Systems Canada (emSYSCAN): 5-year project worthEmbedded Systems Canada (emSYSCAN): 5-year project worth over $50 million; provides platform-based microsystems design and prototyping environments. Shared Infrastructure in Canada’s National Design Network.
Prof. Edmond Cretu
aerosol jet printeraerosol jet printer
In addition:3D printerSonoplot
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maskless lithographySonoplotLaser micromachining …
UBC ECE Research Day, Applied Materials, June 25, 2014
BioMEMS: Applications
BASHIR R (2004) BioMEMS: state-of-the-art in detection opportunities and
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BASHIR, R. (2004) BioMEMS: state of the art in detection, opportunities and prospects. Advanced Drug Delivery Reviews, 56, 1565-1586.
UBC ECE Research Day, Applied Materials, June 25, 2014
Biomedical Microdevices at UBC: drug delivery systems
Arrays of hollowArrays of hollow out-of-plane microneedles for vaccine injectionProf. Boris Stoeber
Stoeber et al 2013 J. Micromech. Microeng. 23 085011
Drug deliveryDrug delivery battery-less device to treat diabetes-
l t d i i lrelated vision lossProf. Mu Chiao
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Chiao et al Lab Chip, 2011,11, 2744-2752
UBC ECE Research Day, Applied Materials, June 25, 2014
Drug discovery and development pipeline
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A virtual space odyssey, Cath O'Driscoll, 2004.
UBC ECE Research Day, Applied Materials, June 25, 2014
Microfluidic systems for cell-based anticancer drug screening
Aim: 3-D cell culture for drug screeningAim: 3 D cell culture for drug screeningApproach:• microfluidic generation of cell-laden hydrogel beadsg y g• hydrogel supports three-dimensional cell cultureCollaboration:• C. Roskelley, M. Bally, BC Cancer Research Centre
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UBC ECE Research Day, Applied Materials, June 25, 2014
Motivation: hydrogel-based cell culturemicroenvironment affects cell phenotype, p yp ,proliferation, differentiation, and migration.
Even small spheroids (containing about 25‐50 cells) are more resistant to killing than
2-D cell culture50 cells) are more resistant to killing than monolayers.
~ 105 – 106 cellsvolumes: ~ 100s μLvolumes: ~ 100s μL
3 D ti
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3-D tissueP Olive and R Durand, Cancer and Metastasis Reviews, 1994
UBC ECE Research Day, Applied Materials, June 25, 2014
On-chip image-based drug screeningMulticellular drug resistanceMulticellular drug resistance
bead in microchannelbead in culture flaskmonolayer in culture flask
Fluorescence assay based on live/dead cell viability stain.
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L. Yu, MC Chen, KC Cheung, Lab on a Chip, 2010
UBC ECE Research Day, Applied Materials, June 25, 2014
One step process: Core/Shell beads (collagen, Matrigel, alginate)
10 days
Core: tumor cells in collagen and Matrigelproteins provide cues from natural extracellular
each bead ~ 8 nL volume
- proteins provide cues from natural extracellular environment; hydrogel scaffold supports cells- cells proliferate, uniformly sized spheroids
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L. Yu, C. Bayly, KC Cheung, MicroTAS 2013Shell: alginate
UBC ECE Research Day, Applied Materials, June 25, 2014
Two-photon microscopy and second harmonic generation
T h t iTwo-photon microscopy to visualize embedded cells.
breast epithelial cells expressing FUCCI cell cycle reporters (Sakaue-Sawano et al., Cell, 2008, , , ,132(3):487.)
Second harmonic generation signal g gvisualizes the collagen fibers.
imaged 4 days post-encapsulation.
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UBC ECE Research Day, Applied Materials, June 25, 2014
Microfluidic design controls oxygen environment; O2 sensorMost solid tumorsMost solid tumors contain regions of hypoxia.
blood vessel
Gradient of O2 in tissue.
Intermittent hypoxia.
low cell proliferation; hypoxia
O. Trédan et al., J Natl Cancer Inst, 2007
Intermittent hypoxia.
0 0 2 t 200 μm
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S. Grist, L. Yu, C. Bayly, KC Cheung, CMBES 20140 0.2 atm 200 μm
UBC ECE Research Day, Applied Materials, June 25, 2014
Model of intermittent hypoxia and re-perfusion
1.5
2
(%)
0 5
1
Oxy
gen
leve
l
5 mm
Alginate 200 400 6000
0.5O
Alginate shell Time (minutes)
Gaseous oxygen levels measured in situusing thin-film optical sensors.
100 μmBead trapCell-laden core bead
Model of intermittent hypoxia in tumours; re-perfusion and re-oxygenation after stroke.
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S. Grist, L. Yu, C. Bayly, KC Cheung, CMBES 2014100 μmBead trap core bead
UBC ECE Research Day, Applied Materials, June 25, 2014
3D culture and drug response
Effects of normoxic vs. hypoxic culture conditions on dose response.
Effects of 2D vs 3D culture on dose response.
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UBC ECE Research Day, Applied Materials, June 25, 2014
Inkjet patterning of living cells for tissue engineeringAim: precise patterning of living cellsAim: precise patterning of living cells
on substratesApproach:• inkjet dispensing• piezoelectric nozzle, drop-on-
demanddemand• hydrogels as tissue scaffoldCollaboration:Collaboration:• E. Cretu, B. Stoeber,
K. Walus
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S. Parsa, M. Gupta, F. Loizeau, K. Cheung, Biofabrication, 2010.
UBC ECE Research Day, Applied Materials, June 25, 2014
Inkjet patterning of living cells
500 μm
Challenges:
> 95% cell viability, 48 hrs after printing
• cell aggregation
• nozzle clogging
• poor reliability of printing precise numberspoor reliability of printing precise numbers of cells over long printing periods (hours)
S Parsa M Gupta F Loizeau K Cheung Biofabrication 2010
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S. Parsa, M. Gupta, F. Loizeau, K. Cheung, Biofabrication, 2010.D. Chahal, A. Ahmadi, KC Cheung, Biotechnology and Bioengineering, 2012.
UBC ECE Research Day, Applied Materials, June 25, 2014
Droplet break-off and cell behaviour: cell travel
high speed imaging:23,121 frames/second
refractive index matchedrefractive index matched holder
ll t l l tcell travels closer to nozzle orifice as expected
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E. Cheng, A. Ahmadi, KC Cheung, CMBES 2014
UBC ECE Research Day, Applied Materials, June 25, 2014
Droplet break-off and cell behaviour: cell reflection
high speed imaging:23,121 frames/second
refractive index matchedrefractive index matched holder
ll i fl t d f thcell is reflected further back into the nozzle after dispensing drop
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E. Cheng, A. Ahmadi, KC Cheung, CMBES 2014
UBC ECE Research Day, Applied Materials, June 25, 2014
Particle Image Velocimetry (PIV) study of droplet formationVelocity field at time = 10 μs shows the ejection of the fluid within the nozzle at the beginning of the droplet ejection cycle.
Equivalent bright-field images of the two frames to show the meniscus evolution during the time in which the PIV images were taken.
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E. Cheng, A. Ahmadi, KC Cheung, FEDSM 2014
UBC ECE Research Day, Applied Materials, June 25, 2014
Summary and Future Work
Microfluidically generated cell laden beads:Microfluidically generated cell-laden beads: 3-D culture environment supports spheroid formation.beads include elements of extracellular matrix.b d h ll t t i l t 3D ltbead core-shell structure improves long-term 3D culture.
Inkjet printing of living cells for tissue engineering: U P ti l I V l i t (PIV) t d t d flUse Particle Image Velocimetry (PIV) to understand flow field inside inkjet nozzle.Strategies for reducing cell reflection and ensure consistent dispensing of cellsdispensing of cells.
Future work: optimize imaging for automated image-based drug-optimize imaging for automated image based drugscreening.Integrated oxygen control and optical oxygen sensors to create and monitor cyclic hypoxic conditions.
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UBC ECE Research Day, Applied Materials, June 25, 2014
AcknowledgmentNSERCNSERCCIHRCFICMC Mi tCMC Microsystems
Dr. Linfen YuDr. Ali AhmadiEric ChengCynthia NiCynthia NiSamantha GristCarmen Bayly
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UBC ECE Research Day, Applied Materials, June 25, 2014