Abstract: To promote early rapid osteogenesis and prevent late implant-related infection, it is critical to develop ef-fective and reliable surface treatment technologies for enhancing both osteogenic and antibacterial prop-erties of titanium alloy implants. Reduced graphene oxide (rGO) is considered a promising modification candidate. However, whether rGO retains its osteogenic and antibacterial functions after being applied to modify titanium alloy surfaces depends on the surface treatment technology employed. In this study, rGO was integrated onto the surface of Ti-35Nb-2Ta-3Zr (TNTZ) alloy through friction stir processing (FSP), yielding a consolidated TNTZ/F-rGO composite. The incorporation of rGO not only significantly im-proved the microhardness and hydrophilicity of the material, but also exhibited positive biological effects in vitro experiments: it effectively promoted the proliferation, osteogenic differentiation, alkaline phos-phatase (ALP) production and extracellular matrix mineralization of BMSCs. Furthermore, TNTZ/F-rGO ex-hibited potent antibacterial activity via surface-contact mechanisms. In summary, the rGO-modified in-tegrated titanium alloy has excellent osteogenic properties and high-efficiency antibacterial ability. This study provides new insights and strategies for the design of graphene-based biomaterials and implant surface modification technologies.

Key words: Osteogenesis, Titanium alloy implants, Friction stir processing, Implant surface modification