Microenvironment-Responsive Metal-Phenolic Nanozyme Release Platform with Antibacterial, ROS Scavenging, and Osteogenesis for Periodontitis.

Periodontitis is a chronic inflammatory disease deriving from dental plaque, characterized by the excessive accumulation of reactive oxygen species (ROS), matrix metalloproteinase (MMP) and other substances, resulting in the destruction of periodontal tissues. At present, the main therapeutic modalities, such as local mechanical debridement and antibiotic delivery, are not only difficult to solve the intractable bacterial biofilm effectively but also tricky to ameliorate the excessive inflammatory response as well as regenerate the impaired periodontal tissues. Herein, we have proposed the TM/BHT/CuTA hydrogel system formed by the self-assembly of the copper-based nanozyme (copper tannic acid coordination nanosheets, CuTA NSs) and the triglycerol monostearate/2,6-di--butyl-4-methylphenol (TM/BHT) hydrogel. The negatively charged TM/BHT/CuTA can retain at the inflammation sites with a positive charge through electrostatic adsorption and hydrolyze in response to the increasing MMP of periodontitis, realizing the on-demand release of the CuTA nanozyme. The released CuTA nanozyme has antibacterial and antiplaque properties. Meanwhile, as a metal-phenolic nanozyme, it can scavenge multiple ROS by simulating the cascade process of superoxide dismutase (SOD) and catalase (CAT). Further, the CuTA nanozyme can modulate the macrophage polarization from M1 phenotype to M2 phenotype through the Nrf2/NF-κB pathway, which reduces the pro-inflammatory cytokines, increases the anti-inflammatory cytokines, and promotes the expression of osteogenetic genes successively, thus relieving the inflammation and accelerating the tissue regeneration of periodontitis. Altogether, this multifunctional nanozyme on-demand release platform (TM/BHT/CuTA) provides a desirable strategy for the treatment of periodontitis.