Additive manufacturing of graphene oxide/hydroxyapatite bioceramic scaffolds with reinforced osteoinductivity based on digital light processing technology

Abstract

In the field of bone tissue engineering, porous hydroxyapatite (HA) bone repair scaffolds with controlled architecture and porosity are challenging to manufacture and lack sufficient osteoinductive activity, which limit its wider clinical application. This study fabricated porous graphene oxide (GO)/HA composite ceramic scaffolds using digital light processing (DLP) technology. The properties of the composite ceramic slurry and the process parameters of curing, degreasing, and sintering were initially examined to ensure molding accuracy. The research showed that a small amount of GO (0.1–0.4 wt%) could better maintain the pore structure and improve the mechanical properties of composite ceramics. Porous scaffolds with pore sizes of 300–400 μm were prepared for co-culture with rat bone marrow mesenchymal stem cells to detect biocompatibility. The results showed that all scaffolds have no cytotoxicity. Compared with HA, the GO/HA ceramic scaffold significantly promoted the cell adhesion, proliferation, and expression of osteogenesis-related genes; GO (0.1–0.2 wt%) /HA scaffolds exhibited superior alkaline phosphatase activity and more effective bone mineralization, showing enhanced osteoinductivity. The porous GO/HA composite scaffold fabricated by DLP presented a strong potential for repairing bone defects.