Synergistic Antibacterial Strategy of AIEgens Photosensitizer CPTQ for Photodynamic Therapy and Ferroptosis-like Bacterial Death to Prevent Dental Caries

Dental caries, primarily caused by Streptococcus mutans ( S. mutans ) biofilms, remains a global health concern. Antimicrobial photodynamic therapy (aPDT) has shown promise in controlling cariogenic bacteria by generating reactive oxygen species (ROS), but the aggregation-caused quenching (ACQ) effect of traditional photosensitizers limits its efficacy. In this study, we developed a novel aggregation-induced emission (AIE) photosensitizer, CPTQ, with an enhanced photodynamic antibacterial efficacy and intrinsic antibacterial properties. CPTQ exhibited superior ROS generation, effective bacterial labeling, and strong membrane anchoring, leading to a significant disruption of bacterial membrane homeostasis and interference with bacterial metabolism. Moreover, CPTQ induced ferroptosis-like bacterial death by triggering lipid peroxidation and oxidative stress, providing a synergistic antibacterial strategy. In vitro results demonstrated that CPTQ effectively inhibited S. mutans growth, while in vivo studies in a rat dental caries model showed significant reductions in cariogenic bacterial load and caries progression. Given its excellent biocompatibility and dual antibacterial mechanisms, CPTQ offers a promising and innovative strategy for the prevention and treatment of dental caries.