The bacterial microenvironment-activated nanocatalytic antibacterial strategy has attracted extensive attention owing to the high specificity to eliminate pathogens, which provides opportunities to solve antibiotic resistance. However, the relatively high pH value and insufficient endogenous H2O2 level in bacterial microenvironment limits the efficiency of Fenton reactions induced by these nanocatalytic agents, leading to unsatisfied antibacterial performance. Herein, bimetallic peroxide was first reported as a high-efficiency antibacterial nanocatalyst with high pH-activated, H2O2 self-supply and synergistic effect-enhanced cascade Fenton chemistry. An isolated spray vial was further developed to achieve in situ gelation at the wound site, adapt to irregular wound surface, and maintain long-term release of nanocatalyst. As a result, wound healing was efficiently promoted corresponding to excellent nanocatalytic antibacterial efficacy. Thus, our in situ sprayed nanocatalytic antibacterial gel provides a promising paradigm for high-efficiency bacterial infection therapy.
Abstract Nano‐catalytic bacterial killing provides new opportunities to address ever‐increasing antibiotic resistance. However, the intrinsic catalytic activity usually depends on a much lower pH conditions (pH = 2–5) than that in the weakly acidic bacterial microenvironments (pH = 6–7) for reactive oxygen species production by Fenton reactions. Herein, a MnSiO 3 ‐based pH‐ultrasensitive “in situ structure transformation” is first reported to significantly promote the adhesion between material and bacteria, and shorten the diffusion distance (<20 nm) to compensate ultra‐short life (<200 ns) of ·OH generated by Mn 2+ ‐mediated Fenton‐like reaction, finally enhancing its nano‐catalytic antibacterial performance in weakly acidic conditions. A separated spray bottle is further designed to achieve in situ gelation at the wound site, which demonstrates excellent shape adaptability to complicated and rough surfaces of wounds, allowing for long‐term nano‐catalyst release. As a result, bacterial‐infected wound healing is efficiently promoted. Herein, the in situ sprayed nano‐catalytic antibacterial gel presents a promising paradigm for bacterial infection treatment.
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