On-site self-assembly of glycopeptide triggered by bioorthogonal ligation to metabolically labeled bacteria for promoting tissue regeneration in methicillin-resistant Staphylococcus aureus (MRSA)-Infected wounds

Antimicrobial resistance presents a daunting challenge in treating drug-resistant wound infections, leading to persistent wounds and high mortality. To address this issue, we developed a precision therapeutic strategy that capitalizes on a universally conserved bacterial characteristic to simultaneously achieve robust bactericidal activity and immunomodulatory tissue regeneration. Our strategy employs metabolic labeling of bacteria using D-amino acid derivatives to selectively introduce tetrazine (Tz) groups into the peptidoglycan of replicating pathogens. A rationally designed trans-cyclooctene-modified glycopeptide (TCO-GP) engages with Tz-labeled bacteria via a highly specific bioorthogonal ligation, inducing an in situ amphiphilic transition that prompts the precise on-site self-assembly of the heptapeptide (KLVFFGC) into membrane-disrupting nanoaggregates exclusively on bacterial surfaces. These nanoaggregates not only disrupt bacterial membrane integrity by imposing mechanical stress but also suppress energy-dependent metabolic pathways, delay cellular growth and division, and inhibit peptidoglycan biosynthesis, thus collectively preventing effective membrane repair. Beyond direct antibacterial effects, the mannose moieties on TCO-GP exhibit considerable pro-regenerative capacity by driving M2 macrophage polarization. This polarization enhances phagocytic activity and facilitates the intracellular clearance of residual bacteria, while simultaneously fostering an immune microenvironment conducive to tissue repair and regeneration. In a rat model of MRSA-infected wounds, our treatment strategy demonstrated comprehensive efficacy by facilitating rapid MRSA clearance, reducing destructive inflammation, stimulating robust angiogenesis, and enhancing collagen deposition, thereby markedly accelerating tissue regeneration.