Effect of gradient biomineral concentrations on osteogenic and chondrogenic differentiation of adipose derived stem cells

Abstract

In this study, we prepared polydopamine-gelatin templated electrospun nanofibers, which were coated with precisely controlled amounts of biominerals in the form of simulated body fluid (SBF). We initially investigated the effects of different mineral concentrations on the in vitro osteogenic differentiation of human adipose derived stem cells (hADSCs), demonstrating the increase in osteogenic differentiation as a function of mineral concentration without any osteogenic supplements. Meanwhile, in the presence of chondrogenic medium, nanofibers with lower mineral contents showed the highest chondrogenic commitment of hADSCs, while more highly mineralized samples greatly inhibited chondrogenesis. We then generated a mineral gradient on the nanofiber surface and examined the hADSC responses under different media conditions. The hADSCs showed a gradient osteoblast phenotype on a mineral gradient of nanofibers under growth media conditions. Under chondrogenic media conditions, hADSCs favored osteogenic differentiation in the more mineralized positions, while lower mineral content induced chondrogenic differentiation of the hADSCs, consistent with the trend in nanofibers with different mineral contents. These results suggest that the controlled presentation of minerals on the material substrate in combination with soluble inducing factors could be used as a tool for stem cell-based osteochondral tissue engineering.