Multi-Functional Applications of Hydrogel Delivery Systems in Inflammatory Bowel Disease: Drug Delivery, Anti-Inflammation, and Intestinal Repair.

Inflammatory bowel disease (IBD) represents a chronic inflammatory disorder of the gastrointestinal tract with a multifactorial etiology that remains incompletely elucidated. Accumulating evidence implicates dysregulation of the intestinal micro-ecosystem, aberrant neuroimmune interactions, and compromised epithelial barrier integrity as key contributors to IBD pathogenesis. While oral administration remains the predominant therapeutic approach, the acidic gastric milieu and enzymatic catabolism markedly compromise drug efficacy. Consequently, selecting an optimal drug delivery method has become a pressing issue in IBD management. As a drug delivery platform, hydrogels, distinguished by their favorable biocompatibility, biodegradability, and injectability, can shield drugs from the harsh gastrointestinal environment. This review offers an innovative and comprehensive analysis of the interactions among various hydrogel application forms, delivery routes, and loaded substances, summarizing the advantages of different types of hydrogels in terms of their anti-inflammatory properties and maintenance of intestinal flora homeostasis, as well as discussing the limitations of current hydrogel deliver systems and looking to the future.