AIE-Active Conjugated Polymer Nanoparticles for Enhanced Photodynamic Bacterial Disinfection and Accelerated Wound Healing

Bacterial infections have become a global health issue owing to the rise of resistant bacterial strains. Although photodynamic therapy (PDT) has emerged as an effective alternative to combat this issue, the development of antibacterial nanophotosensitizers that integrate strong fluorescence, efficient reactive oxygen species (ROS) generation, and low-dosage requirements remains a major challenge. Herein, we report the fabrication of aggregation-induced emission (AIE)-active conjugated polymer nanoparticles (FADM NPs) with optimal photosensitizing properties. The water-dispersible FADM NPs demonstrate excellent bioimaging capability and remarkable photodynamic antibacterial activity, achieving a 99% killing rate against both Gram-positive and Gram-negative bacteria at a low dosage of 1 μg/mL under white light irradiation (20 mW/cm 2, 10 min). Zeta potential and morphological analysis revealed that positively charged FADM NPs electrostatically adhere onto bacterial surfaces, drastically reducing ROS diffusion distances and inducing significant morphological damage. Furthermore, a fluorescent hydrogel wound dressing (FADM NPs@Gel) is developed by incorporating FADM NPs into a biocompatible matrix. Fascinatingly, FADM NPs@Gel accelerates wound healing in an infected mouse model by effectively eliminating bacteria through PDT, exhibiting excellent biocompatibility with negligible side effects. This smartly engineered photodynamic antimicrobial nanosystem offers a revolutionary approach to combat drug-resistant infections with minimal toxicity, paving the way for next-generation antibacterial phototheranostics.