H2S-Responsive Bi2O2CO3@Bi2S3 For Enhanced Photodynamic Therapy Of Periodontitis

In order to eradicate periodontal pathogens and remove excess sulfides that increase inflammation at periodontitis sites, a Bi2O2CO3 microsphere that responds to sulfides to form heterojunctions in situ and enhances photodynamic therapy was designed for the treatment of periodontitis in this study. Bi2O2CO3 microspheres were synthesized by hydrothermal method and responded to sulfides to form Bi2O2CO3@Bi2S3 heterojunctions. The physicochemical properties of the microspheres were characterized using SEM and XRD, and their ability to remove different sulfides was explored. The photocatalytic ability of the microspheres and the reasons for the increased photocatalytic ability of the heterojunctions were investigated. Antimicrobial effects, biofilm disruption, and antimicrobial mechanisms were explored. The ability of microspheres to attenuate H2S-induced cellular inflammation was assessed using q-pcr. A periodontitis model in SD rats (Animal Ethics No. 20231112) was used to evaluate therapeutic efficacy of Bi2O2CO3 via micro-CT and immunohistochemical staining. Bi2O2CO3 responded to sulfides, forming Bi2O2CO3@Bi2S3 heterojunctions, which enhanced photocatalytic activity. Under light, Bi2O2CO3@Bi2S3 generated ROS, destroying bacterial membranes, inactivating DNA/proteins, and killing pathogens and biofilms, as well as decreasing the expression of inflammatory factors in immune cells. In the rat periodontitis model, Bi2O2CO3 absorbed highly expressed H2S, eliminated pathogens, reduced bone resorption, and attenuated inflammation, realizing precise treatment of periodontitis. Bi2O2CO3 absorbs excess H2S in the periodontitis microenvironment, forming Bi2O2CO3@Bi2S3 heterojunctions, enhancing photodynamic sterilization, reducing inflammation, and achieving precise treatment of periodontitis.