Probiotic Bio-Heterojunction Rapidly Restores Periodontal Homeostasis In Periodontitis

Imbalance of microbiota, inflammation, and tissue destruction are hallmark manifestations of disrupted homeostasis in periodontitis. Restoring homeostasis is critical to avert the advancement of periodontitis. While probiotics exhibit promise in periodontitis treatment, their reliance on long-term oral intake limits the efficancy. This study develops an innovative probiotic bio-heterojunction (Probio-HJ) that integrates Ca2+, black phosphorus nanosheets (BPNS) and Lactobacillus rhamnosus (LGG) to rapidly reestablish periodontal homeostasis. Probio-HJ was constructed by electrostatic adsorption. Structural characterization (SEM, TEM, AFM, XRD, XPS, UV-vis) confirmed heterojunction formation, while photothermal, photodynamic, and photoelectric properties were assessed. After evaluations of the antibacterial efficacy and biocompatibility in vitro, a rat periodontitis model was established to evaluate the effects on the periodontal microbiota, local inflammation, and alveolar bone loss. RNA sequencing investigated the mechanisms of alveolar bone remodeling. LGG and BPNS successfully formed a heterojunction-like structure. Under near-infrared (NIR) irradiation, Probio-HJ gradually heated up to 45 °C and generated abundant ROS and photocurrent, which effectively killed periodontal pathogens. Without NIR, it scavenged excess free radicals, ensuring biocompatibility and alleviating inflammation. Additionally, it improved the microbiota structure and reduced alveolar bone loss in the rat periodontitis model after 14 days of treatment. RNA sequencing revealed that Probio-HJ inhibits osteoclast differentiation of macrophages under inflammatory conditions through the PPP3CC/NFATc1 pathway. This study proposes a novel method for constructing living bio-heterojunctions and demonstrates their efficacy in rapidly and effectively restoring periodontal homeostasis in periodontitis, presenting a fresh therapeutic approach for periodontitis.