Natural Broccoli Sprout–Derived Exosomes Encapsulating Bioactive Molecules as a Novel Nanomedicine for Repair of Intestinal Inflammation

Dietary bioactives from broccoli sprouts exhibit anti-inflammatory properties in the prevention and management of inflammatory bowel disease (IBD), but are limited by instability during gastrointestinal (GI) transit and insufficient delivery to inflamed intestinal tissues. Here, we report the discovery and functional characterization of broccoli sprout-derived exosomes (BSDExo) as a naturally occurring nanomedicine that encapsulates endogenous bioactive molecules, including sulforaphane (SFN) and plant miRNAs, and promotes intestinal epithelial repair. BSDExo exhibited a nanoscale size of 40.1 ± 17.2 nm, expressed conserved exosomal protein markers, and were enriched in regulatory miRNAs. Importantly, BSDExo effectively protected encapsulated SFN under simulated gastric and intestinal conditions, demonstrating strong vesicle stability and controlled release. BSDExo (25 µg/mL quantified by total proteins) promoted the proliferation of normal colon epithelial CCD841 CoN cells with a cell viability of 154 ± 5% (p < 0.05). Cellular uptake of fluorescence-labeled BSDExo significantly increased with more severe inflammation stimulation in CCD841 CoN and Caco-2 cells. Secretion of interleukin 8 (IL-8) from inflammation-stimulated colon cells was significantly reduced by the BSDExo treatment (p < 0.05). BSDExo also significantly recovered the epithelial barrier integrity in Caco-2 monolayer that was damaged by LPS or DSS, as assessed by transepithelial electrical resistance (TEER) values (p < 0.05). This study identifies BSDExo as GI-stable, bioactive-rich nanovesicles that selectively target inflamed intestinal epithelium, enhance epithelial repair, and represent a first-in-class, diet-derived nanomedicine with translational potential for IBD.