Peptide-Reduced Platinum-Based Nanozymes for Wound Treatment of Methicillin-Resistant Staphylococcus aureus Infection

Abstract Methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds remain difficult to treat because of antibiotic resistance, biofilm formation, and persistent inflammation, highlighting the need for alternative local antibacterial strategies. Herein, we developed a platinum-based nanozyme (FmY@Pt) through a UV-assisted green reduction process using a tyrosine-containing short peptide (FmY) and evaluated its antibacterial activity and therapeutic potential for treating MRSA-infected wounds. The physicochemical properties and peroxidase(POD)-like activity of FmY@Pt were characterized, and its antibacterial effects and possible mechanisms were evaluated in vitro. The resulting nanozyme exhibited peroxidase-like activity under the tested conditions. In vitro experiments showed that FmY@Pt disrupted bacterial membranes and increased intracellular reactive oxygen species (ROS) levels in MRSA cells. These effects were associated with the antibacterial activity of FmY@Pt. In a mouse model of MRSA-infected skin wounds, the FmY@Pt + H2O2 treatment accelerated wound closure, with the wound closure rate reached approximately 80.8% on day 7. Moreover, bacterial survival rate was reduced to approximately 6.13%, corresponding to a reduction of approximately 93.87% relative to the control group. The treatment was also associated with attenuated inflammatory responses and improvements in tissue repair-related histological indicators. These findings suggest that the antibacterial and inflammation-modulating effects of FmY@Pt may collectively contribute to wound repair under the conditions. This study provides experimental evidence supporting the further investigation of nanozyme-based strategies for the treatment of infected wounds.