Near infrared activated TiO2 nanostructure enable superior antibacterial performance through physicochemical synergy

Titanium, a widely used material for joint replacements and dental restorations, is vulnerable to bacterial infections on its tissue contact surfaces, which can reduce its long-term durability. In this work, TiO 2 nanostructures with varying morphologies were synthesized on titanium surfaces through hydrothermal treatment. The results revealed a transformation of the anatase TiO 2 from nanosheets to nanorods and then to nanowire clusters with increasing treatment time. These nanostructures exhibited superhydrophilicity, increasing surface roughness, excellent photothermal conversion, sustained reactive oxygen species (ROS) release, and significant apatite-forming capability. Importantly, in vitro assays using MC3T3-E1 pre-osteoblast cells confirmed their excellent biocompatibility. Under NIR laser stimulation, the antimicrobial rates of the optimized nanowire cluster structure reached 94.5% against Escherichia coli and 90.5% against Staphylococcus aureus . The results of this study may provide a feasible approach for constructing a physicochemical synergistic antimicrobial system for titanium-based implants with favorable biocompatibility.