Abstract

Highly Efficient Sorting of Adult Stem Cells by Optimally Designed Microfluidic Chip Filtration Coupled with Dean Flow-aided Focusing

Myung-Suk Chun, Principal Research Scientist (Prof. Dr.), Korea Institute of Science and Technology (KIST)

Human bone marrow-derived mesenchymal stem cells (hMSCs) consist of heterogeneous subpopulations with different self-renewal and multipotent capacities. Thus, sorting out a specific hMSC subpopulation with high self-renewal and multipotent capacities is a useful approach to enhance effectiveness of cell therapy. As the continuous sorting, Jung et al. performed flow-based sorting of hMSCs by using optimally designed microfluidic chips based on the hydrodynamic filtration (HDF) principle. For sorting into three subpopulations, over 86% recovery was achieved for each population of cells with complete purity in small cells. In this study, to further improve sorting efficiency and throughput, a spiral channel in the upper layer designed for inertial focusing by Dean flow was coupled with the lower HDF layer. In order to quantify the hMSCs’ sorting efficiency, three subpopulations were set: rapidly self-renewing (RS) (< 23 micrometer), spindle-shaped (SS) (23-35 micrometer), and flattened (FL) (> 35 micrometer) cells. Higher recovery and purity over 91% were achieved than those of our previous results. The results of adipogenic and osteogenic differentiations also demonstrated a successful fractionation of three subpopulations. It should be noted that RS and SS subpopulations showed higher self-renewal and multipotent capacities than those of FL one.