Three-dimensional porous scaffold by self-assembly of reduced graphene oxide and nano-hydroxyapatite composites for bone tissue engineering

Abstract

Three-dimension (3D) porous reduced graphene oxide (RGO) scaffold has attracted increasing attention in bone tissue engineering due to its favorable osteoinductivity. In this paper, a 3D porous RGO composite was prepared from graphene oxide (GO) and nano-hydroxyapatite (nHA) via self-assembly, thus constructing biomimetic scaffold for bone defect reparation. Detailed studies were performed to evaluate its structure, cellular responses, biocompatibility and in vivo bone repair efficiency, emphasizing the influences of the composite on in vivo bone cell growth and mineralization. The as-prepared scaffold was found to significantly enhance the proliferation, alkaline phosphatase activity (ALP) and osteogenic gene expression of rat bone mesenchymal stem cells (rBMSCs). Further in vivo experiment demonstrated that the circular calvarial defects with 4 mm diameter in rabbit were successfully healed by 20% nHA incorporated RGO (nHA@RGO) porous scaffold after 6 weeks implanting, which was visibly quicker than the RGO one. The computed tomography (CT) and histological analysis showed the improved collagen deposition, cell proliferation and new bone formation occurred in the 20% nHA@RGO treated group. These results indicated that the as-prepared porous scaffold has a promising capacity to stimulate mineralization and promote the in vivo defect healing.