Injectable black phosphorus/hyaluronic acid hydrogel for antibacterial and osteogenic applications in periodontitis

The conventional treatment for periodontitis primarily involves mechanical debridement combined with antibiotic therapy. However, this approach faces limitations such as incomplete removal of bacterial biofilms, short intra-pocket drug retention time, and the risk of inducing antibiotic resistance. Sodium hyaluronate (HA), widely used in dental applications due to its excellent biocompatibility, is constrained by rapid degradation, which hampers sustained therapeutic efficacy. To address this, our study developed an injectable photocrosslinked hydrogel (HA-Furan, HA-F) through furan-modified HA, significantly prolonging its degradation time. Black phosphorus nanosheets (BPNSs) were incorporated as a dual-functional nanomaterial, combining photothermal antibacterial activity with osteogenic induction. Their unique two-dimensional layered structure endows BPNSs with exceptional near-infrared (NIR) photothermal conversion efficiency. Under 808 nm NIR irradiation, BPNSs generate localized heat, denaturing bacterial proteins and enabling efficient eradication of pathogens such as Porphyromonas gingivalis . Moreover, BPNSs gradually degrade into calcium phosphate nanoparticles in physiological environments, while mild photothermal therapy enhances osteoblast adhesion, differentiation, and proliferation. This synergistic effect significantly promotes alveolar bone regeneration, offering a critical driving force for periodontal repair. By integrating BPNSs into the HA-F hydrogel, we propose a minimally invasive and multifunctional strategy for periodontitis treatment, merging antibacterial efficacy with osteogenic potential. This strategy not only overcomes the limitations of conventional periodontal therapies but also provides a feasible clinical translation approach for the integrated treatment of periodontal infection and alveolar bone loss. • Injectable photocrosslinked hydrogel with black phosphorus enhances periodontal bone regeneration. • Mild photothermal therapy (40–42 °C) eradicates P. gingivalis and promotes osteogenic differentiation. • BP/HA-F hydrogel shows sustained stability, injectability, and dual antibacterial-osteogenic activity.