Tailorable Metal–Polyphenol Nanoparticles for Targeted Treatment of Inflammatory Bowel Disease

Reactive oxygen species (ROS) exert critical influence in inflammatory bowel disease (IBD). Metal-polyphenol nanoparticles (MPNs) have exhibited a promising ability to regulate ROS levels and restore homeostasis in the context of IBD. However, the relationship between therapeutic efficacy and the type of MPNs requires further investigation. In this research, we synthesized tailorable MPNs by using epigallocatechin gallate (EGCG) and Mg²⁺, Zn²⁺, Ca²⁺, and Cu²⁺ and investigated their therapeutic efficacy for IBD. In vitro experiments confirmed that these MPNs exhibited pH and ROS responsiveness, increased the stability of EGCG, and improved ROS elimination. In vivo experiments demonstrated that these MPNs can effectively accumulate at sites of colonic inflammation after intraperitoneal injection and can continuously scavenge ROS, downregulate inflammatory factors, and restore the intestinal barrier integrity. Compared with other MPNs, Zn-EGCG nanoparticles (NPs) significantly alleviate symptoms of DSS-induced acute colitis in mice. Our work provides strong evidence to support the rational design of MPNs to regulate inflammation.