Gelatin functionalized graphene oxide for mineralization of hydroxyapatite: biomimetic and in vitro evaluation

We report a facile modification of graphene oxide (GO) by gelatin to mimic charged proteins present in the extracellular matrix during bone formation. The bioinspired surface of GO-gelatin (GO-Gel) composite was used for biomimetic mineralization of hydroxyapatite (HA). A detailed structural and morphological characterization of the mineralized composite was performed. Additionally, MC3T3-E1 cells were cultured on the GO-Gel surfaces to observe various cellular activities and HA mineralization. Higher cellular activities such as cell adhesion, cell proliferation, and alkaline phosphatase activity (ALP) were observed on the GO-Gel surface compared with the GO or glass surface. The increase of ALP confirms that the proposed GO-Gel promotes the osteogenic differentiation of MC3T3-E1 cells. Moreover, the evidence of mineralization evaluated by scanning electron microscopy (SEM) and alizarin red staining (ARS) corroborate the idea that a native osteoid matrix is ultimately deposited. All these data suggest that the GO-Gel hybrids will have great potential as osteogenesis promoting scaffolds for successful application in bone surgery.