Size-Dependent Separation of Human Mesenchymal Stem Cells by Applying Microfluidic Chip Filtration

S.-Y. Yu, J.H. Yoo, M.-S. Chun, M.-S. Chang
Korea Institute of Science and Technology (KIST), KR

Keywords: microfluidic chip, stem cell, shear rate, cell separation, hydrodynamic filtration


It is important to separate human bone marrow-derived mesenchymal stem cells (hMSCs) with high multipotential to differentiation and to increase efficacy of cell therapy. We investigated to develop and validate a novel method for collection of desired size of hMSCs by the microfluidic chip realizing the hydrodynamic filtration (HDF) principle. Microfluidic chip filtration has a key advantage capable of continuous operation without applying chemicals affecting cells. The polydimethylsiloxane/glass microfluidic chip is consisting of main, side, and branch channels, where each channel is designed by flow resistance in the network. The side flow plays an important role in focusing the cells to migrate toward the side wall due to virtual boundary of fluid layers that will be diverted into the branch. The size distribution of cultured hMSCs can be determined by hemocytometer, where the cell viability and images are observed by microscope. Prior to cell separations, the side flow effect on performance and validity of microfluidic chip filtration were tested by using model particles. We conducted two cases of bimodal and trimodal separations of hMSCs. The trimodal separation chip shows higher performance compared to the bimodal one, promising possible applications of HDF with multiple branch channels for precise cell fractionations.