MXene-Based Hydrogel Disrupts Bacterial Biofilms and Reprograms Immune Cell Metabolism via Photothermal-Electron Transfer Effects to Reverse Bone Resorption in Periodontitis
Periodontitis, a chronic inflammatory disease caused by bacterial biofilms, leads to alveolar bone resorption and tooth loss. Current treatments fail to eradicate biofilms and reverse inflammation-induced bone loss. Here, we developed an injectable hydrogel (GQM) composed of oxidized gellan gum, quaternized chitosan, and magnesium–tannic acid-modified MXene nanosheets (MTA-Mg). GQM is injectable into periodontal pockets and delivers MTA-Mg, which disrupts biofilms via photothermal effect under near-infrared (NIR) laser irradiation and kills bacteria through electrostatic interactions from quaternized chitosan. MTA-Mg also acts as an interfacial electron transfer agent to activate oxidative phosphorylation, while releasing magnesium and tannic acid to improve mitochondrial function, thereby reprogramming immune cell metabolism toward the M2 macrophage phenotype. In a rat periodontitis model, GQM hydrogel effectively eradicated biofilms, alleviated inflammation, and reversed alveolar bone resorption. This synergistic 'biofilm disruption–immune metabolic reprogramming' strategy offers a novel approach for treating inflammatory bone resorption in periodontitis.