Biodegradable MoOx@MB incorporated hydrogel as light-activated dressing for rapid and safe bacteria eradication and wound healing

Abstract

Wounds infected with drug-resistant bacteria are hard to treat, which remains a serious problem in clinical practice. An innovative strategy for treating wound infections is thus imperative. Herein, we describe the construction of a nanocomposite from biocompatible poly(vinyl alcohol) (PVA)/polyethylene glycol (PEG) hydrogel loaded biodegradable MoO_x nanoparticles (NPs) and photosensitizer methylene blue (MB), denoted as MoO_x@MB-hy. By incorporating MoO_x@MB NPs, the nanocomposite hydrogel can act as a photoactivated wound dressing for near-infrared-II 1064 nm and 660 nm laser synergetic photothermal–photodynamic therapy (PTT–PDT). The key to PTT-induced heat becomes the most controllable release of MB from MoO_x@MB-hy to produce more ¹O₂ under 660 nm irradiation. Importantly, MoO_x@MB-hy can consume glutathione (GSH) and trap bacteria nearer to the distance limit of ROS damage to achieve a self-migration-enhanced accumulation of reactive oxygen species (ROS), thereby conquering the intrinsic shortcomings of short diffusion distance and lifetime of ROS. Consequently, MoO_x@MB-hy has high antibacterial efficiencies of 99.28% and 99.16% against Amp^r E. coli and B. subtilis within 15 min. Moreover, the light-activated strategy can rapidly promote healing in wounds infected by drug-resistant bacteria. This work paves a way to design a novel nanocomposite hydrogel dressing for safe and highly-efficient antibacterial therapy.