Controlling of stem cell fate through geometrical micropillars during cell expansion

Abstract

Multipotency is the ability of stem cells to differentiate into adipogenesis, osteogenesis and chondrogenesis. In general, stem cells lose their multipotency during cell expansion. The purpose of this study is therefore to slow down the loss of multipotency of stem cells during cell expansion by using different surface topographies which are circle, rectangle and grill. In this study, human mesenchymal stem cells (hMSCs) were expanded from passage 3 to 13 on different surface topographies and at different time points, they were differentiated into adipogenesis, osteogenesis and chondrogenesis. The results show that different surface topographies can direct the morphology of stem cells thus affect their multipotency during cell expansion. hMSCs were growing disorderly on rectangle and circle topographies and it was observed that circle performed best in early passage while rectangle promote multipotency in late passage. hMSCs which were aligned with grill surface topography performed weakest throughout the study. It was believed that stem cells which were growing orderly on grill surface was proliferating fastest hence they get exhausted and thus terminating their multipotency earlier than the rest. Due to time constrains, the future works include repeating the whole experiment to verify the results. Once the results are established, sizes of circle or rectangle can be tuned to retain the multipotency of stem cells in long term passage.