Bacteria-targeting nanozyme with NIR-II photothermal enhanced catalytic effect for antibacterial therapy and promoting burn healing

Nano-photothermal platforms based on the second near-infrared (NIR-II) spectral window attract considerable attention in antimicrobial treatment for the negligible bacterial resistance and deeper penetration in biological tissues. Nevertheless, combining NIR-II photothermal therapy (PTT) with diversified therapeutic modalities for synergistic and enhanced therapeutic efficacy remains challenging for clinical trials. Herein, we report a bacteria-targeting nanozyme based on hollow-structured Cu2MoS4 (PV@HCMS) for performing synergistic therapy of NIR-II (1064 nm) PTT and chemodynamic therapy (CDT). PV@HCMS with superb photothermal conversion efficiency and peroxidase-like (POD-like) catalytic performance could generate highly cytotoxic •OH via NIR-II-enhanced Fenton-like reactions. Polyethyleneimine-vancomycin (PV) modified copolymers conjugated via amide bonds endows PV@HCMS with robust bacterial eradication property through a dual-targeting approach, in turn favoring the synergistic PTT-CDT. Both in vitro and in vivo antimicrobial evaluation show satisfactory bactericidal efficacy and biocompatibility. Of special note, PV@HCMS is further incorporated into the thermosensitive hydrogel poloxamer F127 to form a composite dressing (PHF) with outstanding skin regeneration function and antimicrobial activity for the comprehensive treatment of burn infection. This study proposes a multi-modal collaborative therapy based on nanozymes for enhanced anti-infective efficacy in different scenarios through the optimal design of both composition and morphology.