Transforming Pathological H 2 S Into a Photodynamic Amplifier: In Vivo Formation of Bi 2 O 2 CO
Danyang Wang, Ying Wang, Zhibang Li, Xinwei Liu, Kai Li, Yi Chen, Junkun Feng, Baojin Ma, Wenjun Wang, Jianhua Li, Shaohua GeABSTRACT
Current periodontitis management is hindered by the inability to effectively reverse the dysbiotic microenvironment of persistent infection and restore immune homeostasis. Although photodynamic therapy (PDT) presents a promising non‐invasive antibacterial strategy, its clinical efficacy remains limited by poor microenvironmental selectivity and insufficient immunomodulatory capacity. Herein, we engineer a microenvironment‐responsive “trash‐to‐treasure” PDT strategy based on Bi 2 O 2 CO 3 nanosheet‐assembled microspheres. This platform actively scavenges excess hydrogen sulfide (H 2 S) within the periodontal pocket, triggering an in situ transformation into Bi 2 O 2 CO 3 @Bi 2 S 3 heterojunctions. This H 2 S‐triggered conversion neutralizes the pro‐inflammatory gasotransmitter and establishes an S‐scheme heterojunction with enhanced photocatalytic activity. The resulting reactive oxygen species (ROS)‐mediated oxidative stress, together with targeted disruption of bacterial iron metabolism, enables highly efficient photodynamic eradication of major periodontopathogens such as Porphyromonas gingivalis . Moreover, Bi 2 O 2 CO 3 ‐mediated scavenging of pathological H 2 S alleviates inflammatory responses in human gingival fibroblasts and reactivates macrophage respiratory burst for intracellular bacterial clearance. In vivo evaluations in a rat periodontitis model demonstrate effective inflammation resolution, suppression of alveolar bone loss, and robust tissue regeneration. This work introduces an intelligent therapeutic strategy that hijacks pathological H 2 S as a photodynamic amplifier, establishing a microenvironment‐adaptive PDT paradigm for periodontal infection.