γ-Fe2O3/Polydopamine/TiO2 nano-porous array composite coating (FPTCC) to modulate antibacterial, osteogenesis, and osseointegration through photothermal-magnetic response

• A γ-Fe 2 O 3 /polydopamine/TiO 2 nano-porous arrays composite coating with photothermal-magnetic responsiveness. • The capability of the coating to modulate antibacterial, osteogenesis and osseointegration can be enhanced under the intervention of NIR irradiation and static magnetic field. • The coating provides a potential strategy for the prevention and treatment of delayed-union or non-union of fracture. Delayed-union or non-union of fractures due to infection and localized low osteogenic activity is a great physical, psychological and financial burden for patients. Therefore, there is an urgent need to find an economical and effective solution. In this study, a γ-Fe 2 O 3 /polydopamine/TiO 2 nano-porous arrays composite coating (FPTCC) with photothermal-magnetic responsiveness was fabricated. The characterization of FPTCC was analyzed by FT-IR, SEM, and EDS. The photothermal ability, photothermal stability and magnetic hysteresis curves were examined to evaluate photothermal-magnetic response properties of FPTCC. The results demonstrated that FPTCC has outstanding hydrophilicity, strong substrate bonding and stable remotely controlled photothermal-magnetic response properties. Furthermore, in vitro and in vivo biological experiments were performed to verify the capability of FPTCC to modulate antibacterial, osteogenesis and osseointegration under the intervention of NIR irradiation and static magnetic field. In conclusion, the FPTCC with biocompatibility, antibacterial, and osteogenic capabilities may provide a potential strategy for the prevention and treatment of delayed-union or non-union of fracture.