NIR-II responsive coating for antibacterial synergistic effect of photothermal and chemodynamic therapy

Due to the advantages of non-invasive, low toxicity, high specificity and no drug resistance, photothermal therapy (PTT) and chemodynamic therapy (CDT) as an alternative to antibiotic therapy have been widely used in the treatment of implant infections. Herein, a coating which is synergistic antibacterial by photothermal therapy and chemodynamic therapy triggered by near-infrared (NIR) laser was successfully prepared on the surface of Ti sheet (TGC). First, TGC has strong absorption in the second near-infrared window (NIR-II, 1000–1700 nm) optical region and has good photothermal effect. Secondly, TGC produces ·OH in a Fenton-like reaction under the action of NIR laser, killing floating bacteria. Under the irradiation of NIR-II laser, TGC exerts the photothermal/chemodynamic effect, and has an efficient killing effect on Gram-negative E. coli and Gram-positive S. aureus , and effectively inhibits the further reproduction of bacteria to form biofilms. This combined photoresponsive/Fenton-like multimodal antimicrobial coating shows advantages in the field of implant anti-infection.