Self-Assembling Nano-Antimicrobial Oligopeptides With Dual Offense-Defense Functions for Synchronously Achieving High Activity and Biosafety.

Self-assembling nano-antimicrobial peptides (nano-AMPs) hold significant promise for addressing bacterial resistance, yet the persistent activity-biocompatibility paradox remains a major scientific challenge. Here, we present an "integrated offense‒defense" strategy in which binding to mammalian cells is inhibited (defense) but bacterial membrane insertion is improved (offense), effectively decoupling antimicrobial potency from host cytotoxicity. We demonstrated that nano-AMPs with moderate surface potentials (∼+20 mV) preferentially bind to bacteria and exhibit minimal interactions with mammalian cells because of the inherent charge disparity between bacterial and mammalian cell membranes. Experimental and theoretical analysis revealed that systematic sequence engineering resulted in peptide nanofibers with loose molecular packing and high exposure of hydrophobic residues. The optimized nano-AMP exhibited potent antimicrobial activity (MIC of 5∼6 µM) and exceptional biosafety (therapeutic index TI = HC10 / MIC > 30; selectivity index SI = IC20 / MIC> 50). A murine skin wound infection model confirmed the antimicrobial efficacy of this peptide, which reduced the bacterial burden and promoted wound healing.