Three-dimensional porous graphene nanosheets synthesized on the titanium surface for osteogenic differentiation of rat bone mesenchymal stem cells

Abstract Currently, graphene and its derivatives, used for surface modification of orthopedic and dental implants, are mainly in the form of two-dimensional planar structure. There is little information of three dimensional porous graphene nanosheets used as coating materials of titanium and its alloys. In the present study, three dimensional porous graphene nanosheets were first synthesized on the pure titanium surface. The physicochemical properties and osteogenic activity of the three dimensional porous graphene nanosheets-modified titanium (rGO@Ti) were systematically investigated. The results suggested that rGO@Ti showed super hydrophilicity, rough surface and excellent biocompatibility, and could enhance alkaline phosphatase (ALP) activity, extracellular matrix (ECM) mineralization and collagen secretion of rat bone mesenchymal stem cells (rBMSCs). Meanwhile, the expressions of osteogenesis related genes containing ALP, bone morphogenic protein-2 (BMP-2), osteocalcin (OCN), and osteopontin (OPN) on rGO@Ti were improved. The osteogenic differentiation of rBMSCs on rGO@Ti may be ascribed to both its superior protein adsorption ability and physical stimulation induced by the unique structure of three dimensional porous graphene nanosheets.