The effect of glow discharge plasma surface modification of polymers on the osteogenic differentiation of committed human mesenchymal stem cells

Little is known of the effect of material surfaces on stem cell differentiation. The present study has addressed the hypothesis that the interaction of mesenchymal stem cells (MSCs) with material surfaces modified by glow discharge plasma is a major regulator of osteogenic differentiation. We found that biaxially oriented polypropylene (BOPP) plasma treated in ammonia significantly reduced up-regulation of expression of osteogenic marker genes, such as alkaline phosphatase (ALP), bone sialoprotein (BSP) and osteocalcin (OC). In contrast, ALP expression was up-regulated when cultured on treated Nylon-6 polyamide (Ny-t) but was substantially reduced when cultured on its pristine counterpart (Ny-p) on day 3. On day 7, ALP expression was down-regulated with MSCs cultured on Ny-t although its expression level was up again on day 14. BSP was expressed weakly on day 3, but was up-regulated when cultured on Ny-t and Ny-p. Its expression reached its maximum on day 14 when cultured on a polystyrene control, while it was cyclically up-regulated on Ny-t. Similarly, there was a slight increase in OC expression when MSCs were cultured on Ny-t and Ny-p on day 3, when compared to control. Thus, the nature of the surface can directly influence MSCs differentiation, ultimately affecting the quality of new tissue formation with BOPP-t suppressing osteogenic differentiation.