LAUSR

Graphene (Gr) presents promising applications in regulating the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Light illumination is regarded as a spatiotemporally controllable, easily applicable and noninvasive mean to modulate materials' responses. Herein, Gr transferred silicon (Gr/Si) with Schottky junction is utilized to evaluate the visible light-promoted osteogenic differentiation of BMSCs. Under light illumination, light-induced charges, owing to the formation of Schottky junction at the interface of Gr and Si, accumulated on the surface and then changed the surface potential of Gr/Si. Schottky junction and surface potential at the interface of Gr and Si was measured by photovoltaic test and scanning kelvin probe microscopy. ALP activity and Quantitative real-time PCR measurement showed that such variations of surface improved the osteogenic differentiation of BMSCs, and the activation of the voltage-gated calcium channels through surface potential and accumulation of cytosolic Ca2+ could be the reason. Moreover, X-ray photo-electron spectroscopy characterization showed that surface charge could also affect BMSCs differentiation through promotion or inhibition of the osteogenic growth factors adsorption. Such light-promoted BMSCs osteogenic differentiation on Gr/Si may have many potential in biomedical materials or devices for bone regeneration application.