Dual-Responsive Microsphere Based on Natural Sunflower Pollen for Hemostasis and Repair in Inflammatory Bowel Disease

Noninvasive treatment of inflammatory bowel disease with
lower
gastrointestinal bleeding is a major clinical challenge. In this study,
we designed an orally targeted microsphere based on sunflower pollen
microcapsules to localize the site of inflammatory injury and promote
hemostasis and tissue repair. Due to the Eudragit and ascorbate palmitate
coatings, EL/AP@PS(t+Dex) demonstrates pH- and enzyme-responsive release
of loaded drugs and helps to resist the harsh environment of the gastrointestinal
tract. Both in vitro and in vivo experiments show the characteristics
of inflammation targeting and mucosal adhesion, which reduce the systematic
exposure and increase the local drug concentration. In the DSS model,
orally administered EL/AP@PS(t+Dex) significantly alleviates hematochezia,
inhabits intestinal inflammation, and remarkably promotes the recovery
of the intestinal epithelial barrier to reduce the exposure of intestinal
microvessels. Furthermore, EL/AP@PS(t+Dex) optimized the composition
of intestinal microbiota, which benefits intestinal homeostasis. This
finding provides a fundamental solution for the treatment of intestinal
bleeding caused by inflammatory bowel disease (IBD).