Epigallocatechin gallate-based nanoparticles with reactive oxygen species scavenging property for effective chronic periodontitis treatment

Chronic periodontitis is one of the most common oral diseases worldwide and the excessive local reactive oxygen species (ROS) level of periodontitis aggravates the destruction of periodontal tissue. Scavenging of ROS to remodel the periodontal microenvironment and relieve inflammatory response may be an effective strategy for periodontal therapy. Tea polyphenol-derived functional nanomaterials often serve as ROS scavenger in inflammatory disease for their antioxidant and anti-inflammation ability. However, the therapeutic effect of tea polyphenol resources remains unsatisfactory due to the tedious encapsulation, poor stability, and low operational bioactivities. In this work, functionalized epigallocatechin-3-gallate (EGCG, green tea derivative) nanoparticles (NPs) were developed via a one-step polyphenolic condensation reaction. The resulting polyphenol-based nanoparticles with potent antioxidant capacity improved the chemical stability of epigallocatechin gallate. The EGCG NPs can scavenge ROS effectively, and down-regulate the expression of pro-inflammatory cytokines by reprograming macrophages from M1 to M2 phenotype. In vivo results illustrate that EGCG NPs can inhibit the alveolar bone loss from 1346.8 ± 244.9 μm to 596.1 ± 92.1 μm via decreasing ∼ 50% ROS level, as well as reduce osteoclastic activity in a rat model of chronic periodontitis. Therefore, the biosafe EGCG NPs have great potential in ROS-scavenging and provide a promising strategy to remodel the inflammatory microenvironment by inducing the polarization of macrophages from M1 toward M2 phenotype for efficient periodontitis therapy.