Near-Infrared-ActivatedPolydopamine-Platinum Nanozymesfor Infected Wound Healing

Abstract Chronic bacterial infections and oxidative stress severely impede wound healing, necessitating innovative strategies that simultaneously eradicate pathogens and modulate the hostile wound microenvironment. Herein, we develop a near-infrared (NIR)-responsive multifunctional nanoplatform (APDA-Pt) by integrating l-arginine-assisted polydopamine (APDA) with catalase-mimetic platinum nanoparticles (Pt NPs) to achieve synergistic photothermal antibacterial therapy and oxidative stress regulation. APDA serves as both a robust photothermal transducer and a versatile scaffold to anchor ultrasmall Pt NPs with high dispersion and enhanced catalytic utilization. Under NIR irradiation, APDA-Pt rapidly elevates local temperature, enabling efficient membrane disruption and broad-spectrum antibacterial efficacy (>99% inactivation of E. coli and S. aureus). Meanwhile, Pt NPs exhibit catalase-mimetic activity by catalyzing the decomposition of H2O2 into H2O and O2, whereas the APDA framework provides intrinsic antioxidant activity through its redox-active catechol groups, thereby synergistically alleviating oxidative stress. In an S. aureus-infected murine wound model, APDA-Pt combined with NIR irradiation markedly accelerates wound closure (≈90% by day 10), reduces bacterial burden by over 4 orders of magnitude, and promotes collagen deposition and tissue regeneration, without inducing systemic toxicity. This work presents an externally triggered multifunctional therapeutic platform that integrates photothermal bacterial eradication with antioxidant regulation, providing a promising strategy for chronic wound management.