Self-Oxygenating RB@ZIF-8/MnO2 enhanced biofilm eradication for photodynamic antibacterial therapy in periodontitis

• A multifunctional nanoplatform RB@ZIF-8/MnO 2 enhanced ROS production under hypoxic conditions. • RB@ZIF-8/MnO 2 eradicated planktonic and multispecies biofilms under light irradiation. • The nanoplatform reduced subgingival burden in vivo, shifted microbiota toward health. • RB@ZIF-8/MnO 2 mediated aPDT alleviated hypoxia and inflammation and preserved alveolar bone. Antimicrobial photodynamic therapy (aPDT) has garnered attention for periodontal therapy; however, its application is limited by hypoxia and the complexity of subgingival biofilms in the periodontal pocket. This study reports a self-oxygenating photosensitizer, RB@ZIF-8/MnO 2 (RZM), constructed by encapsulating Rose Bengal (RB) in ZIF-8 and conformally depositing a MnO 2 nanozyme shell. MnO 2 catalyzes endogenous H 2 O 2 to O 2 , increasing local oxygen and thereby amplifying RB-mediated reactive oxygen species (ROS) under 532 nm irradiation. RZM preserved ZIF-8 crystallinity, and a mildly cationic surface that favors biofilm interaction, achieving synergistic killing of S. gordonii and P. gingivalis when supplemented with low H 2 O 2 , and eradicates tri-species biofilms with pronounced structural disruption and metabolic collapse. In a rat periodontitis model, RZM-aPDT reduces the subgingival bacterial burden, shifts the plaque microbiota toward a healthier profile, alleviates tissue hypoxia and inflammation, and significantly preserves alveolar bone. These results indicate that oxygen self-sufficiency, combined with biofilm-oriented delivery, enables potent photodynamic antibacterial therapy for periodontal disease.