An Injectable Hydrogel Enabling Photo-Temporal Modulation of Asymmetric Adhesion for Tissue Fixation and Prevention of Postoperative Peritoneal Adhesion

Peritoneal adhesion is a common problem after abdominal surgery, causing great distress to patients. To address the problems of complicated preparation and limited application of existing asymmetric anti-adhesion barriers, this study reports a photo-temporal modulation of asymmetric adhesion injectable hydrogel (GDSP hydrogel). This GDSP hydrogel is initially crosslinked with excellent biocompatible gallic acid-modified chitosan and zwitterionic group-modified aldolylated dextran, while poly(ethylene glycol) diacrylate (PEGDA) is introduced as the photoinitiation component, forming a gradient asymmetric structure after UV irradiation without additional contact and environmental stimulation. This structural design allows the hydrogel to precisely regulate the adhesion process in the time dimension, achieving in situ immobilization on the wound surface, and then effectively resisting biofouling from fibrin, fibroblasts, platelets, and bacteria etc. GDSP hydrogel also has excellent antioxidant ability, and in vitro and in vivo experiments have demonstrated that it can reduce postoperative inflammatory responses by modulating macrophage phenotype. In the mouse abdominal wall defect-cecum abrasion model, GDSP hydrogel effectively inhibited the formation of postoperative adhesions, elevated t-PA, and suppressed PAI-1. Therefore, GDSP hydrogel is a promising candidate for the prevention of postoperative peritoneal adhesions. © 2025 Wiley-VCH GmbH.