A heterogeneous TiO2/SrTiO3 coating on titanium alloy with excellent photocatalytic antibacterial, osteogenesis and tribocorrosion properties

In order to meet the clinical demand for titanium implants, the heterogeneous structure of TiO2/SrTiO3 coating was in situ fabricated on the surface of Ti6Al4V alloy by a facile way. The well-designed Ti6Al4V/TiO2/SrTiO3 composite exhibits a strong photocatalytic antibacterial efficiency against Escherichia coli (E. coli). The suitable energy band structure, improved light absorption and enhanced carrier separation of TiO2/SrTiO3 heterojunction facilitate the generation of bactericidal reactive oxygen species (ROS) under the illumination of UV light. The biocompatible SrTiO3 component effectively favors the adhesion, proliferation and osteogenic differentiation of human bone mesenchymal stromal cells (hBMSCs) in vitro. It is worth noting that the dense oxide coating provides a reliable barrier against tribocorrosion for the titanium alloy substrate, and the wear volume loss of the Ti6Al4V/TiO2/SrTiO3 reduces to 1/8 of that of the bare Ti6Al4V alloy in simulated body fluid. In this work, a multifunctional coating system was proposed to provide inspiration for the development of novel artificial bone implant materials.