Hydrogel-Shielded Ellagic Acid Nanoparticles Prolong Colonic Retention and Mitigate DSS-Induced Colitis via Reactive Oxygen Species Scavenging.

Inflammatory bowel disease (IBD) is characterized by oxidative stress imbalance and intestinal barrier disruption. Reducing excessive ROS has become a promising therapeutic strategy. Compared with conventional polyphenols, nanomaterials offer greater stability and bioavailability for ROS scavenging. Here, ellagic acid (EA) was converted into uniform nanoparticles (EAs) with reactive oxygen scavenging capacity through horseradish peroxidase (HRP)-mediated oxidative polymerization and subsequently encapsulated in the anti-gastric acid hydrogel F-DP to obtain the hybrid system F-DP@EAs. EAs reduced ROS, MDA, NO, IL-1β, and TNF-α levels in vitro, while increasing IL-4 and IL-10 expression, thus alleviating inflammation. Herein, F-DP@EAs prolonged intestinal retention time and exerted superior protective effects in the DSS-induced colitis model. Oral F-DP@EAs lowered DAI, preserved colon length, increased glutathione (GSH) and superoxide dismutase (SOD), decreased NO and MDA, restored zonula occludens-1 (ZO-1), and reduced mucosal lesions. These findings demonstrate that combining nanoparticle and hydrogel technologies markedly enhances the preventive and protective efficacy of EA, highlighting F-DP@EAs as a promising candidate for future IBD therapy.