Purine‐Based Ir(III) Photosensitizers for Efficient Treatment of Periodontal Inflammation

Abstract Photodynamic therapy (PDT) presents a promising approach for combating periodontitis, an infectious disease triggered by bacteria. However, the hypoxic environment within periodontal pockets poses challenges for PDT efficacy. In this study, novel purine‐based C^N ligands are utilized to develop Ir(III) complexes with enhanced reactive oxygen species (ROS) generation capacity for periodontitis treatment. The type I/II PDT performance of Ir(III) is greatly enhanced by the purine ligands, which leads to potent bactericidal and biofilm elimination efficacy. In a rat model of periodontitis, local application of these purine‐based Ir(III) complexes effectively achieves antibacterial and anti‐inflammatory effects while promoting tissue repair under clinical luminaire exposure. This PDT strategy utilizing purine‐based Ir(III) complexes circumvents the need for antibiotics and surgical intervention, emerging as a promising, non‐invasive approach for managing periodontitis.