A Self-Oxygenating Photosensitizer Enhances Photodynamic Antibacterial Therapy In Periodontitis

There is reduced antibacterial efficacy in hypoxic microenvironments for existing photosensitizers exhibit. So, we designed a photosensitizer with catalytic oxygen-generation properties to enhance the therapeutic effect of antibacterial photodynamic therapy (aPDT) for periodontitis. We assembled Bengal Rose, ZIF-8, and MnO₂ together and demonstrated the successful synthesis of the nanomaterial through a series of experiments. Under 532 nm laser irradiation, the photosensitizer can generate reactive oxygen species (ROS) to kill bacteria and disrupt biofilms. Moreover, in the presence of low-concentration hydrogen peroxide, the ROS production was significantly enhanced, leading to a substantial improvement in antibacterial efficacy. Subsequently, we established a rat periodontitis model to confirm the excellent antibacterial effects and periodontitis-alleviating properties of the novel photosensitizer. Bacterial, cellular, and animal models are used to confirmed that the novel photosensitizer can catalyze low-concentration hydrogen peroxide to produce oxygen, increasing local oxygen levels. The elevated oxygen content effectively alleviates hypoxia in periodontal pockets while promoting the generation of ROS, thereby enhancing antibacterial efficacy and significantly improving the therapeutic outcomes of aPDT. This study successfully synthesized a novel photosensitizer and demonstrated its excellent antibacterial properties and therapeutic efficacy against periodontitis, offering new perspectives for optimizing clinical antimicrobial therapies.