Multipotent perivascular stem cells (PVCs) have gained much attention as an alternative source for cell based regenerative medicine in recent years. Due to their rarity in human tissues, developing methods to efficiently isolate and expand PVCs from various fetal and adult tissues is necessary to obtain a clinically relevant number of cells that maintain progenitor potency. Here, we report on a non-enzymatic isolation (NE) method of PVCs from human umbilical cords (HUCs) and compare its efficiency with the conventional collagenase treatment method (CT) in terms of proliferation and immunophenotypes. The cells isolated by NE displyed acceptable surface marker profile of PVCs and showed multilineage (osteogenic, chondrogenic, and adipogenic) differentiation potential. While both methods provided similar levels or patterns of proliferation and immunophenotypes, PVCs by NE retained a higher level of CD146(+) frequency compared to that of CT over passage. Furthermore, we have investigated potentials of various exogenous factors to promote proliferation of HUCPVCs in vitro. Among these factors, supplementation of basic fibroblast growth factor (bFGF) provided the optimal condition to significantly enhance the proliferation rate of HUCPVC and increased a proportion of stage-specific antigen-4 (SSEA-4) positive subset. Collectively, our study suggests that NE method with bFGF supplementation offers an alternative way to obtain sufficient numbers of HUCPVCs with higher number of primitive SSEA-4(+) subpopulation that are applicable in therapeutic doses for regenerative medicine.

• Borim An(Department of Internal Medicine, School of Medicine, Kangwon National University)
• Seok-Ho Hong(Department of Internal Medicine, School of Medicine, Kangwon National University, Stem Cell Institute, Kangwon National University)