A Multifunctional, In Situ Fast‐Gelling Polyurethane‐Graft‐Chitooligosaccharide Hydrogel for Postoperative Adhesion Therapy

In situ fast‐gelling hydrogels with one‐side adhesion performance, antibacterial, antioxidant properties are needed for postoperative adhesion therapy. This study reports the development of a novel polyurethane‐graft‐chitooligosaccharide (PU–COS) nano‐emulsion as a precursor solution. We then introduced FeGlu as a crosslinker and bioactive agent at varying concentrations to construct in situ fast‐gelling PU–COS/FeGlu hydrogels. Their adhesive, bioactive, degradation and biological properties were systematically evaluated. The results showed that PU–COS nano‐emulsion was synthesized and developed by inducing a grafting copolymerization reaction with diameter of approximately 34.9 nm and zeta potential of −93.86 mV. PU–COS/FeGlu hydrogels have been fabricated via an initial rapid FeGlu‐mediated crosslinking followed by hydrogen bonding‐mediated crosslinking. They exhibit one‐side adhesive properties owing to the differences in crosslinking density. FeGlu also imparts the PU–COS/FeGlu hydrogels with functional properties, including antibacterial activity and antioxidant capacity. Furthermore, these hydrogels exhibit controllable degradation properties, as well as good cytocompatibility and blood compatibility. Experimental studies using a rat sidewall defect–caecum abrasion model demonstrate that PU–COS/FeGlu hydrogels were effective in preventing postoperative adhesions. This study provides an innovative strategy for developing on‐demand multifunctional anti‐adhesion hydrogels with promising potential for preventing postoperative adhesions.