Phycocyanin functionalized selenium nanoparticles for type I photodynamic antibacterial therapy and wound healing.

Photodynamic therapy (PDT) has emerged as a promising treatment for drug-resistant bacterial infections by avoiding the abuse of antibiotics. However, most PDTs rely on reactive oxygen species (ROS) generated a type II process, which limits the antimicrobial effect in a hypoxic microenvironment. Herein, we reported phycocyanin functionalized selenium nanoparticles (Se@PC NPs) for type I photodynamic antibacterial therapy and wound healing. Se@PC NPs can generate hydroxyl radicals and superoxide radicals under visible light irradiation, effectively disrupting the bacterial membrane structure and demonstrating sterilization against Gram-positive and Gram-negative bacteria. Notably, experiments and histological tests have demonstrated that Se@PC NPs effectively eliminate bacteria, regulate proinflammatory cytokines against bacteria-induced inflammation, promote collagen deposition, and accelerate wound healing. Consequently, this study provides a strategy for the design of highly effective type I photosensitizers for photodynamic antibacterial therapy.