Multimodal Synergistic Antimicrobial Activity of the Copper-Doped and Oxygen-Defective In Situ Nanocoating on Medical...

To combat escalating antibiotic resistance in titanium implant-associated infections, oxygen-vacancy-rich polydopamine/TiCu nanocoating (PDA/p-TiCu-300 °C) was developed on medical-grade titanium, uniquely enabling synergistic photothermal (PTT), photodynamic (PDT), and sonodynamic (SDT) antimicrobial strategies. Unlike previous dual-modal approaches, this trimodal strategy, activated by near-infrared light and ultrasound, achieved exceptional broad-spectrum bactericidal efficacy against both Escherichia coli (99.19% killing) and Staphylococcus aureus (95.03% killing) via enhanced reactive oxygen species (ROS) generation and membrane disruption. The engineered oxygen vacancies within the PDA/p-TiCu-300 °C nanocoating significantly boosted ROS production, outperforming conventional photocatalytic materials. Crucially, the nanocoatings demonstrated excellent in vitro cytocompatibility. This PTT-PDT-SDT platform exhibits synergistic multimodal bactericidal activity, overcoming the limitations of existing strategies and representing a paradigm shift in implant surface modification with significant translational potential against severe infections.