Ag/Ag2O with NIR-Triggered Antibacterial Activities: Photocatalytic Sterilization Enhanced by Low-Temperature Photothermal Effect

Purpose: A synergistic antibacterial system employing photocatalytic performance and low-temperature photothermal effect (LT-PTT) with the potential for infectious skin wound healing promotion was developed. Methods: Ag/Ag 2 O was synthesized with a two-step method, and its physicochemical properties were characterized. After its photocatalytic performance and photothermal effect were evaluated under 0.5 W/cm 2 808 nm NIR laser irradiation, its antibacterial activities in both planktonic and biofilm forms were then studied in vitro targeting Staphylococcus Aureus (S. aureus) , and the biocompatibility was tested with L-929 cell lines afterward. Finally, the animal model of dorsal skin wound infection was established on Sprague-Dawley rats and was used to assess infectious wound healing promotion of Ag/Ag 2 O in vivo. Results: Ag/Ag 2 O showed boosted photocatalytic performance and local temperature accumulation compared with Ag 2 O when exposed to 0.5 W/cm 2 808 nm NIR irradiation, which therefore endowed Ag/Ag 2 O with the ability to kill pathogens rapidly and cleavage bacterial biofilm in vitro. Furthermore, after treatment with Ag/Ag 2 O and 0.5 W/cm 2 808 nm NIR irradiation, infectious wounds of rats realized skin tissue regeneration from a histochemical level. Conclusion: By exhibiting excellent NIR-triggered photocatalytic sterilization ability enhanced by low-temperature photothermal effect, Ag/Ag 2 O was promising to be a novel, photo-responsive antibacterial agent. Keywords: semiconductor/metal hybrid, antibacterial agent, photo-responsive antibacterial activity, reactive oxygen species, infectious wound skin model