Biodegradable Nanospray for Sunlight‐Activated Photodynamic Antibacterial Therapy and Wound Healing

ABSTRACT The increasing resistance of pathogenic bacteria challenges current skin disinfection strategies, while the non‐degradability of traditional cationic antimicrobials limits their clinical safety. Conventional photodynamic therapy is limited by complex application requirements. To address these limitations, we developed a biodegradable, sunlight‐activated photodynamic cationic nanospray (NP ^PORPMn ). Under environmentally friendly and readily accessible sunlight irradiation (NP ^PORPMn +L), NP ^PORPMn efficiently generates reactive oxygen species and works synergistically with its quaternary ammonium cations to exert potent antibacterial effects. This dual‐action significantly reduces the inflammatory response in infected microenvironments and accelerates wound healing in infections caused by Staphylococcus aureus ( S. aureus ) and methicillin‐resistant Staphylococcus aureus ( MRSA ). Skin disinfection experiments further demonstrate that NP ^PORPMn +L can eliminate pathogenic bacteria and resident microbial communities on the skin surface. This study presents an innovative, biodegradable, and clinically safe nanospray platform that harnesses the convenience of sunlight activation to provide a promising strategy for combating antibiotic‐resistant infections.