Injectable CuS-loaded carboxymethyl and sulfonated chitosan hydrogel with antibacterial and self-healing properties promoting periodontal tissue regeneration.

Periodontitis is a chronic infectious disease caused by bacteria, characterized by progressive destruction of periodontal soft and hard tissues, ultimately leading to tooth loss. To treat periodontitis, this study combined the advantages of nanoparticles and hydrogels, and successfully developed an injectable aldehyde-functionalized PF127, carboxymethyl and sulfonated chitosan hydrogel doped with copper sulfide nanoparticles (CuS/PCS). The CuS/PCS hydrogel was synthesized through a dynamic Schiff base reaction. The injectable hydrogel forms a gel in situ after injection into deep periodontal pockets, achieving high antibacterial activity without causing bacterial resistance. The CuS/PCS hydrogel exhibited good biocompatibility, maintained cell viability, promoted stem cell proliferation, and demonstrated significant antimicrobial activity. In the rat periodontitis model, the CuS/PCS hydrogel effectively reduced inflammation and bone loss, and promoted periodontal tissue regeneration. These results suggest that CuS/PCS hydrogel could be a promising biomaterial for the treatment of periodontitis.