Hybrid metallic nanozyme with nitric oxide-releasing photothermal coating for accelerated infected diabetic wound healing.

Infected diabetic wounds are prone to developing bacterial biofilms and are difficult to treat due to a lack of strategies that can eliminate drug-resistant bacteria. Conventional antibiotics can't achieve the desired antibacterial effect due to their limited penetration into the biofilm, which makes the treatment challenging. In this study, we developed NIR-responsive nitric oxide (NO) releasing Ce: Zn nanoflowers (PDA@SNP@Ce:Zn NFs) to combat the drug-resistant bacteria by the synergistic antibacterial effect of metal ions and photothermal effect. PDA@SNP@Ce:Zn NFs exhibited significant antibacterial and antibiofilm effects against Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus (SA). The nanoflowers exhibited significant inhibitory effects on the virulence of MRSA and SA, including spreading motility, secretion of phenol-soluble modulin proteins, and staphyloxanthin, after laser irradiation. The PDA@SNP@Ce:Zn NFs were able to cause membrane disruption and eradicate the MRSA and SA biofilms that were analyzed by scanning electron microscope. Additionally, these nanoflowers significantly accelerated wound healing in MRSA-infected diabetic rats by reducing the inflammation and promoting angiogenesis at the wound site. Our findings suggested that the developed photothermal nanoflower system would be an alternate approach to prevent drug-resistant bacterial infections.