ROS-responsive sprayable hydrogel as ROS scavenger and GATA6+ macrophages trap for the prevention of postoperative abdominal adhesions.

Postoperative abdominal adhesions are a common clinical problem after surgery and can cause many serious complications. Current most commonly used antiadhesion products are less effective due to their short residence time and focus primary on barrier function. Herein, we developed a sprayable hydrogel barrier (sHA-ADH/OHA-E) with self-regulated drug release based on ROS levels at the trauma site, to serve as a smart inflammatory microenvironment modulator and GATA6+ macrophages trap for non-adherent recovery from abdominal surgery. Sulfonated hyaluronic acid (HA) conjugates modified with adipic dihydrazide (sHA-ADH), and oxidized HA conjugates grafted with epigallocatechin-3-gallate (EGCG) via ROS-cleavable boronate bonds (OHA-E) were synthesized. sHA-ADH/OHA-E hydrogel was facilely fabricated within 5 s after simply mixing sHA-ADH and OHA-E through forming dynamic covalent acylhydrazones. With good biocompatibility, appropriate mechanical strength, tunable shear-thinning, self-healing, asymmetric adhesion, and reasonable in vivo retention time, sHA-ADH/OHA-E hydrogel meets the requirements of a perfect physical barrier. Intriguingly, sulfonic acid groups endowed the hydrogel with satisfactory anti-fibroblast and macrophage attachment capability, and were demonstrated for the first time to act as polyanion traps to prevent GATA6+ macrophages aggregation. Importantly, EGCG could be intelligently released by ROS triggering to alleviate oxidative stress and promote proinflammatory M1 macrophage polarize to antiinflammatory M2 phenotype. Further, the fibrinolytic system balance was restored to reduce fibrosis. Thanks to the above advantages, the sHA-ADH/OHA-E hydrogel exhibited excellent anti-adhesion effects in a rat sidewall defect-cecum abrasion model and is expected to be a promising and clinically translatable antiadhesion barrier.