Biomimetic Catalytic System Mimicking Immune Defense and Tissue Healing for Dynamic Treatment of Skin Infections

Managing skin infections requires both pathogen eradication and tissue regeneration, yet current therapeutics rarely address these sequential needs. Here, we designed a biomimetic catalytic system (MBC) to recapitulate the dynamic, dual-phase functionality of the innate immune response. In the infectious microenvironment, MBC mimics neutrophil-mediated killing by using CeO₂ nanoparticles (NPs) and Br ions to exert haloperoxidase-like activity, generating HBrO from endogenous H₂O₂ to eliminate MRSA biofilms. Upon infection clearance, the system autonomously transitioned to a healing phase. CeO₂ NPs switch to macrophage-like antioxidant functions, scavenging reactive oxygen species, resolving inflammation, and restoring immune homeostasis. In three murine infection models of MRSA-infected wounds, pressure ulcers, and subcutaneous abscesses, MBC achieves comprehensive therapeutic efficacy.