Osteogenic Differentiation of Mesenchymal Stem Cells in their Native Niche Like Environment

Abstract Niche is an important microenvironment regulating stem cell's natural behavior and its fate. Mesenchymal Stem Cells (MSCs) are the most common cells used in bone tissue engineering. However, common culture procedures do not retain MSCs in their niche and apply in vitro expansion which can cause abnormal behavior. In this study, we propose that, by Keeping MSCs in their native niche, natural behavior of these cells and their interactions are maintained and the quality of differentiation will enhance. In our previous studies, we isolated MSCs kept in their native niche-like environment (native-MSCs) in the form of aggregates. Herein, in order to explore the osteogenic differentiation of these cells, they were isolated from bone marrow, and in vitro osteogenesis was assessed via alizarin red and real time PCR. It was observed that they differentiated after 6 days, which is remarkably faster than the conventional 21-day period. Higher expression of Runx2, Spp1 and alkaline phosphatase in native-MSCs also confirmed in vitro results. We also examine their attachment on poly (L-lactic acid) (PLLA) scaffold. In sum, native-MSCs exhibited faster differentiation than expanded MSCs which proves the importance of keeping stem cells in their niche