ROS-triggerable dual nanocoated probiotics for inflammatory bowel disease treatment.

Inflammatory bowel disease (IBD), an immune-mediated chronic gastrointestinal disease, is difficult to treat because its specific pathogenic mechanisms are currently unclear, and its recurrence rate is high. Probiotic therapies have been used to treat IBD; however, challenges, including poor digestive stability and unstable treatment effects, remain. Catechins are natural flavonoids with anti-inflammatory and anti-oxidant properties. In this study, we link catechins to the amino side chain of ethylene glycol chitosan through phenylboronic acid as a nano coating for probiotics, and enhance their stability under acidic conditions with sodium alginate. The resulting double-layer nano coating system is triggered by reactive oxygen species (ROS) for probiotic-small molecule combination therapy. After oral administration, the nano coating helps probiotics stabilize and pass through the harsh digestive environment, respond to the high ROS environment at the site of inflammation, and release anti-inflammatory drugs. The coating breaks down and adheres to the cell surface while releasing probiotics to regulate the intestinal microbiota environment and achieve combined therapy. The method exerts a certain therapeutic effect in a dextran sulfate sodium (DSS)-induced mouse model of ulcerative colitis. This study combines traditional targeted drug therapy concepts with biological therapies to improve IBD treatment efficacy and reduce side effects.