Microenvironment-Adaptive Nanozyme for Accelerating Drug-Resistant Bacteria-Infected Wound Healing.

Reactive oxygen species (ROS) is favorable for antibacterial infection but its overproduction results in serious inflammatory response and aggravates hypoxic state of wound tissue, which would be detrimental to healing stages of proliferation and remodeling. Here, an atomic-dispersion iron (Fe)-doped oxygen-deficient molybdenum oxide MoO 3-X (ADFM) bifunctional nanozyme, featuring with implanted peroxidase-like and enhanced catalase-like activity, has been developed for decomposing H 2 O 2 into strongly oxidizing hydroxyl radicals (•OH) for prevention of bacterial infection and into plentiful O 2 for healing stages. Therein, the introduction of Fe into MoO 3-X primarily produced an asymmetric electron density difference by elongating the bond length between metal atoms, synchronously stabilizing adsorption of •OH and weakening the adsorption of O 2 . ADFM also showed unimaginably high aqueous dispersity and pH-adaptive ROS regulation in wound microenvironment, both of which were favorable for ADFM to fully exert enzyme-like activity for timely antibacterial and efficient wound-healing action. ADFM thus achieved efficient healing of drug-resistant bacteria-infected wounds in vivo, at ultralow dosage of 30 μg mL -1 against 10 6 CFU mL -1 extended spectrum β-lactamases producing Escherichia coli, exhibiting a wound-healing efficiency of ∼10 mm 2 per day, which sets a benchmark among these noble-metal-free nanozyme-based wound-healing agents. This article is protected by copyright. All rights reserved.