Composite Film with Antibacterial Gold Nanoparticles and Silk Fibroin for Treating Multidrug-Resistant E. coli-Infected Wounds

The progressively increasing degree of multiple antibiotic resistance in Gram-negative bacteria challenges the treatment of severe bacterial infection-induced chronic skin wounds. To address this problem, we developed a straightforward strategy to prepare a composite film consisting of antibacterial nanoparticles (4,6-diamino-2-pyrimidinethiol-functionalized gold nanoparticles, DAPT-Au NPs) and a silk fibroin (SF) mixed-matrix membrane (DAPT-Au-SF MMM) as a wound dressing for treating multidrug-resistant (MDR) E. coli- induced infection. The good hydrophilicity of SF allows the highly effective release of DAPT-Au NPs from the composite film to combat pathogens within minutes. The antibacterial activity of the composite film is maintained regardless of antimicrobial susceptibility. DAPT-Au-SF MMMs also promote healing in rat wounds infected by clinically isolated MDR E. coli. Our findings provide a new strategy to extend the use of gold nanomaterials and SF-based wound dressings, especially against drug-resistant bacterial infections.