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“NOODLE FIBER” OVERCOMING LIMITATIONS OF ELECTROSPINNING AND MICROFLUIDICS-BASED MICROFIBER JiSoo Park 1 and Sang-Hoon Lee 1,2 1 School of Biomedical Engineering, Korea University, Seoul, Republic of Korea 2 KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea ABSTRACT Microfiber spun by electrospinning technology and microfluidics-based technology have been developed as a powerful tool in tissue engineering applications; however, there have been limits in cumbersome fabrication process using hazardous solvents and down-scaling, respectively. Here, we present a novel method to spin several strands of microfibers at a time, like noodles, with ultrathin diameter in few micron-scale diameter without using solvents based on microfluidics overcoming those limitations of conventional methods. With this platform, we fabricated a porous membrane made of ultrathin microfibers without using solvents and confirmed its potential as a various-drugs/cells loaded sheet or 3D scaffold using microfluidics technology that can be a useful tool in tissue engineering applications. KEYWORDS: microfluidics-based microfiber, sub-micron scale, fibrous porous membrane INTRODUCTION Electrospinning has evolved as a powerful tool in various tissue engineering applications by providing the ability to control biomaterial composition, fiber diameter, and drug/biomolecule incorporation into a scaffold [1]. However, there are several limitations in the electrospinning technology that should not be overlooked. First, organic solvent is needed to fabricate scaffolds made of fibers after electrospinning that may be harmful to cells or destruct drug or biomolecule that was loaded in the fiber. Also, electrospinning technology is not able to encapsulate cells in the fiber which can be useful for tissue engineering application. Lastly, electrospun fibers cannot be spatiotemporally and digitally coded with various drugs or cells at once. As an alternative of electrospinning technology with such limitations, the spinning technologies by using microfluidic system have been reported to overcome those limits [2]. With microfluidics-based spinning technology, the fibers with various biocompatible materials can be spun by a simple fabrication process without using organic solvent. Also, not only the cells, but also various sensitive drugs or biomolecules can be easily loaded in the fiber and it can be spatiotemporally coded with different compositions and topologies. But, still, it is challenging to down-scale the diameter of fibers to few-micron scale like electrospun fibers and to construct porous sheet usable as a scaffold for cell culture. Therefore, microfluidic spinning technology still requires a quantity of improvement for the extensive application. Here, we suggest a novel method to spin several strands of microfibers at a time with ultrathin diameter in few micron-scale diameter (Figure 1) and we would like to call this type of fibers as “noodle fiber” because of the resemblance to the appearance of noodle. EXPERIMENTAL AND RESULTS To fabricate Noodle fibers, a PDMS microfluidic chip with microgrooves at the outlet of the sample channel was fabricated using standard soft lithography methods. The flow rate of each fluid was controlled using a syringe pump; the sample (1% w/v sodium alginate) flow rate was fixed at 1 μL/min while the sheath (3% w/v CaCl 2 dissolved in isopropanol) flow rate was varied from 0.1 mL/min to 1 mL/min. The Noodle fibers were continuously produced in the reaction channel without deformation or discontinuity. Scanning Electron Microscope (SEM) images (Figure 2, 4) and confocal images (Figure 3) were obtained to observe the diameter of the fibers and the porous membrane. 1422 978-0-9798064-8-3/μTAS 2015/$20©15CBMS-0001 19 th International Conference on Miniaturized Systems for Chemistry and Life Sciences October 25-29, 2015, Gyeongju, KOREA
