Engineering Cu nanoclusters with aggregation-induced emission for photodynamic healing of wound with drug-resistant bacteria-infection

Efforts to expedite the development of novel antimicrobial agents without drug resistance are imperative to combat drug-resistant bacterial infections. In this study, Cu nanoclusters (NCs) with aggregation-induced emission (AIE) were designed by manipulating the pH to control the aggregation of Cu(I) complexes on the surface of a Cu(0) core. The resulting Cu NCs exhibited excellent photodynamic antimicrobial activity against a wide range of bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA), through a synergistic interplay of intrinsic and photodynamic antimicrobial mechanisms. This was achieved by the copious generation of reactive oxygen species (ROS) that are lethal to bacteria. In addition to that, these Cu NCs displayed minimal cytotoxicity and excellent biocompatibility, enabling the promoted healing of MRSA-infected wounds in mice through eliminating bacterial infection, and alleviating inflammation without causing systemic harm or impairing blood and liver functions. This study represents the first successful development of AIE-featured Cu NCs-based photodynamic antimicrobials, which may shed light on the design of other AIE-featured metal NCs, contribute to a better understanding of NC's luminescence fundamentals, and add fuels to the development of metal NCs-based nanomedicine.