Advancements in hydrogel-based drug delivery systems for the treatment of inflammatory bowel disease: a review.

Inflammatory bowel disease (IBD) is a chronic disorder that affects millions of individuals worldwide. However, current drug therapies for IBD are plagued by significant side effects, low efficacy, and poor patient compliance. Consequently, there is an urgent need for novel therapeutic approaches to alleviate IBD. Hydrogels, three-dimensional networks of hydrophilic polymers with the ability to swell and retain water, have emerged as promising materials for drug delivery in the treatment of IBD due to their biocompatibility, tunability, and responsiveness to various stimuli. In this review, we summarize recent advancements in hydrogel-based drug delivery systems for the treatment of IBD. We first identify three pathophysiological alterations that need to be addressed in the current treatment of IBD: damage to the intestinal mucosal barrier, dysbiosis of intestinal flora, and activation of inflammatory signaling pathways leading to disequilibrium within the intestines. Subsequently, we discuss in depth the processes required to prepare hydrogel drug delivery systems, from the selection of hydrogel materials, types of drugs to be loaded, methods of drug loading and drug release mechanisms to key points in the preparation of hydrogel drug delivery systems. Additionally, we highlight the progress and impact of the hydrogel-based drug delivery system in IBD treatment through regulation of physical barrier immune responses, promotion of mucosal repair, and improvement of gut microbiota. In conclusion, we analyze the challenges of hydrogel-based drug delivery systems in clinical applications for IBD treatment, and propose potential solutions from our perspective.

In situ bioprinting of double network anti-digestive xanthan gum derived hydrogel scaffolds for the treatment of enterocutaneous fistulas.

The clinical treatment of enterocutaneous fistula is challenging and causes significant patient discomfort. Fibrin gel can be used to seal tubular enterocutaneous fistulas, but it has low strength and poor digestion resistance. Based on in situ bioprinting and the anti-digestive properties of xanthan gum (XG), we used carboxymethyl chitosan (CMC) and xanthan gum modified by grafted glycidyl methacrylate (GMA) and aldehyde (GCX) as the ink to print a double network hydrogel that exhibited high strength and an excellent anti-digestive performance. In addition, in vitro studies confirmed the biocompatibility, degradability, and self-healing of hydrogels. In our rabbit tubular enterocutaneous fistula model, the in situ printed hydrogel resisted corrosion due to the intestinal fluid and acted as a scaffold for intestinal mucosal cells to proliferate on its surface. To summarize, in situ bioprinting GCX/CMC double network hydrogel can effectively block tubular enterocutaneous fistulas and provide a stable scaffold for intestinal mucosal regeneration.