Electrophoretic Deposited Stable Chitosan@MoS2 Coating with Rapid In Situ Bacteria-Killing Ability under Dual-Light Irradiation

Developing in situ disinfection methods in vivo to avoid drug-resistant bacteria and tissue toxicity is an urgent need. Here, the photodynamic and photothermal properties of the chitosan-assisted MoS2 (CS@MoS2) hybrid coating are simultaneously inspired to endow metallic Ti implants with excellent surface self-antibacterial capabilities. This coating, irradiated by only 660 nm visible light (VL) for 10 min, exhibits an antibacterial efficacy of 91.58% and 92.52% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. The corresponding value is 64.67% and 57.44%, respectively, after irradiation by a single 808 nm near infrared light for the same amount of time. However, the combined irradiation using both lights can significantly enhance the efficiency up to 99.84% and 99.65% against E. coli and S. aureus, respectively, which can be ascribed to the synergistic effects of photodynamic and photothermal actions. The former produces single oxygen species under 660 nm VL while the latter induces a rise in temperature of implants, which can inhibit the growth of both E. coli and S. aureus. The introduction of CS can also promote the biocompatibility of implants, which provides a facile, rapid, and safe in situ bacteria-killing method in vivo without needing a second surgery.