Mesoporous Silica Supported Silver–Bismuth Nanoparticles as Photothermal Agents for Skin Infection Synergistic Antibacterial Therapy

The emergence of multidrug resistant bacteria has resulted in plenty of stubborn nosocomial infections and severely threatens human health. Developing novel bactericide and therapeutic strategy is urgently needed. Herein, mesoporous silica supported silver–bismuth nanoparticles (Ag-Bi@SiO₂ NPs) are constructed for synergistic antibacterial therapy. In vitro experiments indicate that the hyperthermia originating from Bi NPs can disrupt cell integrity and accelerate the Ag ions release, further exhibiting an excellent antibacterial performance toward methicillin-resistant Staphylococcus aureus (MRSA). Besides, under laser irradiation, Ag-Bi@SiO₂ NPs at 100 µg mL⁻¹ can effectively obliterate mature MRSA biofilm and cause a 69.5% decrease in the biomass, showing a better therapeutic effect than Bi@SiO₂ NPs with laser (26.8%) or Ag-Bi@SiO₂ NPs without laser treatment (30.8%) groups. More importantly, in vivo results confirm that ≈95.4% of bacteria in abscess are killed and the abscess ablation is accelerated using the Ag-Bi@SiO₂ NPs antibacterial platform. Therefore, Ag-Bi@SiO₂ NPs with photothermal-enhanced antibacterial activity are a potential nano-antibacterial agent for the treatment of skin infections.