A Pt@ZIF-8/ALN-ac/GelMA Composite Hydrogel with Antibacterial, Antioxidant, and Osteogenesis for Periodontitis

Periodontitis is a chronic inflammatory disease caused by oral pathogens, and the osteogenic potential of human periodontal ligament stem cells (hPDLSCs) is severely impaired under the inflammatory environment. Current clinical periodontitis treatment strategies such as surgical interventions and antibiotic delivery still suffer from poor antibacterial efficacy, difficulty in ameliorating excessive inflammatory responses and slow periodontal tissue regeneration. Here, we have innovatively developed a non-surgical treatment strategy based on a functional composite hydrogel. A composite hydrogel system (Pt@ZIF-8/ALN-ac/Gel) containing bioactive zeolite imidazolate framework-8 (ZIF-8) integrated with platinum nanoparticles (Pt@ZIF-8) and alendronate acrylamide (ALN-ac) was constructed on the basis of gelatin methacryloyl (GelMA) to achieve enhanced antibacterial effect and reactive oxygen species (ROS) scavenging ability while promoting the osteogenic potential of hPDLSCs. We confirmed that Pt@ZIF-8/ALN-ac/Gel was able to continuously release Zn2+ and exerted an obvious antibacterial effect against Porphyromonas gingivalis. In vitro experiments proved that Pt@ZIF-8/ALN-ac/Gel had good biocompatibility, while efficiently featuring excellent reactive oxygen species (ROS) scavenging capacity, increasing alkaline phosphatase activity, and promoting extracellular matrix mineralization by hPDLSCs. In vivo, Pt@ZIF-8/ALN-ac/Gel significantly inhibited the alveolar bone deterioration and reduced osteoclast activation and inflammation, thereby promoting the regeneration of damaged tissues. These findings demonstrated superior therapeutic efficacy in the reported clinical periodontitis treatment, exhibiting great potential for application.