Endoscopic Delivery of Hydrogels: A Novel Strategy for Treating Early-Stage Gastrointestinal Tumors.

This review systematically illustrates the application and research progress of endoscopically delivered hydrogels as a novel strategy in the endoscopic treatment of early-stage gastrointestinal tumors. It focuses on analyzing the unique physicochemical properties, biological functions, and clinical value of hydrogels as submucosal injection materials, and delves into their core roles in achieving sustained mucosal lifting, effective hemostasis, and wound repair during endoscopic submucosal dissection (ESD). Representative hydrogel materials, such as chitosan, hyaluronic acid, and sodium alginate, are driving the evolution of ESD technology from a mere "resection" procedure toward an integrated "lift-resect-repair" therapeutic model, owing to their excellent biocompatibility, injectability, and controllable degradability. Although challenges in clinical translation remain, including long-term safety, precise control of degradation rates, and scalable production, the field is poised for further breakthroughs with the development of smart responsive hydrogels and their deep integration with emerging technologies.