Injectable Asymmetric Adhesive‐Antifouling Bifunctional Hydrogel for Peritoneal Adhesion Prevention

Abstract Peritoneal adhesion is a common problem after abdominal surgery and can lead to various medical problems. In response to the lack of in situ retention and pro‐wound healing properties of existing anti‐adhesion barriers, this work reports an injectable adhesive‐antifouling bifunctional hydrogel (AAB‐hydrogel). This AAB‐hydrogel can be constructed by “two‐step” injection. The tissue adhesive hydrogel based on gallic acid‐modified chitosan and aldehyde‐modified dextran is prepared as the bottom hydrogel (B‐hydrogel) by Schiff base reaction. The aldehyde‐modified zwitterionic dextran/carboxymethyl chitosan‐based hydrogel is formed on the B‐hydrogel surface as the antifouling top hydrogel (T‐hydrogel). The AAB‐hydrogel exhibits good bilayer binding and asymmetric properties, including tissue adhesive, antifouling, and antimicrobial properties. To evaluate the anti‐adhesion effect in vivo, the prepared hydrogels are injected onto the wound surface of a mouse abdominal wall abrasion‐cecum defect model. Results suggest that the AAB‐hydrogel has antioxidant capacity and can reduce the postoperative inflammatory response by modulating the macrophage phenotype. Moreover, the AAB‐hydrogel could effectively inhibit the formation of postoperative adhesions by reducing protein deposition, and resisting fibroblast adhesions and bacteria attacking. Therefore, AAB‐hydrogel is a promising candidate for the prevention of postoperative peritoneal adhesions.