Targeted intestinal barrier repair via probiotic-derived engineered outer membrane vesicles: A 3A1M strategy with antioxidant, anti-inflammatory, anti-ferroptotic, and microbiome modulation effects

Intestinal barrier disruption, driven by oxidative stress, ferroptosis, immune imbalance, and gut microbiota dysbiosis, plays a crucial role in inflammatory bowel disease (IBD) pathogenesis. Current treatments are often ineffective and cause side effects, emphasizing the need for novel therapies. Here, we have developed an engineered probiotic-derived outer membrane vesicle (OMV), GDO@CM, combining antioxidant gallic acid (GA) and anti-inflammatory H 2 S for targeted intestinal barrier repair. Constructed from Escherichia coli Nissle 1917 (EcN)-derived OMVs, GA and DATS are incorporated into the hydrophilic inner cavity and lipid bilayer, respectively, while mannose-decorated chitosan (CM) is electrostatically attached to the OMVs surface, enhancing stability and enabling targeted delivery to damaged colonic lesions. GDO@CM efficiently enters activated immune cells and epithelial cells, where GA scavenges reactive oxygen species and inhibits ferroptosis, while H 2 S amplifies anti-inflammatory effects. OMVs further synergize with GA and DATS to suppress pathogenic bacteria. These combined actions facilitate effective barrier repair and alleviate IBD symptoms. Single-cell RNA sequencing reveals that GDO@CM reduces inflammation, increases the proportion of reparative M2 macrophages and intestinal stem cells, and promotes epithelial cell proliferation via the APP/CD74 axis. Our findings establish GDO@CM as a promising multi-target therapeutic for IBD, offering a novel strategy for intestinal barrier restoration. Engineered OMVs-based nanoplatform GDO@CM delivers antioxidant gallic acid and anti-inflammatory H 2 S to effectively restore intestinal barrier integrity, modulate immunity, inhibit ferroptosis, and rebalance gut microbiota, thereby alleviating inflammatory bowel disease.