Trapping effect of surface deficient cocrystal synergizes with bimetallic nanoparticles against bacterial infection...

Metal nanoparticles exert broad-spectrum antimicrobial effects through in situ generation of reactive oxygen species (ROS). However, the limited penetrability of ROS restricts the scope of antimicrobial activity of these nanoparticles. Herein, we develop core-shell nanoparticles composed of a surface-defective cocrystal shell and a Cu/Zn bimetallic core. Surface defects are generated by etching myricetin from a berberine-dihydromyricetin cocrystal, and bacterial adsorption efficiency peaks when the cocrystal contains 40 % myricetin. Similarly, Cu²⁺ doping on the surface of Zn nanoparticles to form a bimetallic core can optimize the ROS generation efficiency by facilitating effective electron transfer. Nanoparticles with this combined core-shell structure not only capture bacteria effectively but also draw bacteria into the ROS-killing range of the metal particles, thereby enhancing activity against drug-resistant bacteria. The feasibility of antibacterial infection was further validated in wounds of mice infected with Escherichia coli and Staphylococcus aureus. This strategy could be used to optimize antimicrobial nanoparticles with ROS-generating functionality and could have an impact on combating bacterial resistance.