pH-Triggered Size-Tunable Silver Nanoparticles: Targeted Aggregation for Effective Bacterial Infection Therapy.

The rapid spread of drug-resistant pathogens threatens human health. To address the current antibacterial dilemma, the development of antibiotic-free strategies using nanotechnology is imperative. In this study, silver nanoparticles (Ag-P&C NPs) with pH-sensitive charge reversal and self-aggregation capacities are successfully synthesized. In the acidic microenvironment of bacterial biofilms, protonation of the surface peptide enhances the affinity of Ag-P&C NPs for bacteria, which can make Ag-P&C NPs prone to target and penetrate into biofilms, and the self-aggregated capacity helps Ag-P&C NPs remain in biofilms for a long time to disrupt bacterial biofilm formation. In addition, biocompatible Ag-P&C NPs are utilized in three types of bacteria-infected animal models. They exhibit an excellent performance in killing bacteria, inhibiting plaque biofilms, and ameliorating inflammatory responses. In conclusion, this study offers new insights into antibiotic-free antibacterial strategies, and exhibits promising application prospects.