Tetrahydroxy Diboron-Initiated Injectable Hydrogel with Integrated Rapid Gelation, Fatigue Resistance, Bioadhesion, Antibacterial Activity, ROS Scavenging, and Osteoinduction for Periodontitis Treatment

Injectable hydrogels are promising for periodontitis treatment, yet achieving rapid gelation, mechanical strength, and multifunctionality under physiological conditions is challenging. Here, we report a tetrahydroxy diboron (THDB)-initiated hydrogel comprising N,N-dimethylacrylamide (DMAA), chlorhexidine, and carboxymethyl chitosan (CMCS), which gels within 2 min without deoxygenation. THDB reacts with vinyl monomers and oxygen to overcome inhibition while undergoing structural evolution to form functional domains. The hydrogel features: (1) dynamic hydrogen bonding and B–O/N coordination for enhanced strength; (2) THDB–CMCS interaction for strong bioadhesion; (3) boronic acid-induced acidity for antibacterial activity against P. gingivalis, S. mutans, S. aureus, and E. coli; and (4) reactive oxygen species (ROS) scavenging via residual B–B bonds to promote osteogenesis. In vivo, it accelerates alveolar bone regeneration in a rat periodontitis model. This one-step injectable platform integrates gelation, reinforcement, adhesion, antibacterial, and antioxidative properties, offering strong therapeutic potential for periodontitis and related inflammatory diseases.