Synthesis and antibacterial properties of Ga-doped TiO 2 nanorods under NIR-responsive synergistic effects

Titanium (Ti) is biologically inert material, lacking antibacterial activity and osteoconductive properties, which may lead to implant failure. To address these issues, a surface-modified film is developed that combines inherent antibacterial properties with synergistic antibacterial functionality in response to near-infrared (NIR) light. Titanium dioxide (TiO 2 ) nanorods were prepared on a titanium surface via the hydrothermal method. Utilizing the physical perforating properties of TiO 2 nanorods combined with the specific ability of gallium (Ga) to disrupt bacterial iron (Fe) metabolism, different concentrations of Ga 3+ were doped. The microstructure, composition, and related physicochemical properties of the film layer were investigated. To further enhance antibacterial efficacy, photothermal therapy and photodynamic therapy were integrated by irradiating the film with 808 nm NIR light. Results demonstrated that Ga-doped TiO 2 films exhibited outstanding synergistic antibacterial activity under 808 nm NIR irradiation. Specifically, the highest antibacterial rate of irradiated samples against Escherichia coli (E. coli) reached 98.1%, and the highest antibacterial rate against Staphylococcus aureus (S. aureus) reached 98.5%. Furthermore, the films demonstrated favorable osteoconductive properties in in vitro mineralization experiments. This approach offers a new strategy for addressing issues of implant infection and inadequate osteogenic performance.