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.