Smart hydrogels for postoperative adhesion prevention: Mechanisms, material innovations, and clinical potential

Postoperative adhesion (POA) is a common surgical issue that can cause serious secondary problems. Current clinical strategies primarily focus on preventive measures, with physical barriers being the predominant method. However, the limited adaptability and short retention of static physical barriers like films and hydrogels in dynamic physiological environments have hindered their long-term therapeutic effectiveness. Recent advancements in stimulus-responsive biomaterials have catalyzed the development of smart hydrogels, positioning them as next-generation anti-adhesion barriers. These hydrogels offer spatiotemporal control over mechanical properties, drug release, and microenvironment regulation by responding to stimuli such as temperature, pH, light, reactive oxygen species (ROS), and ion signals. Many review articles have explored the use of smart hydrogels in biomedical fields, but there is a shortage of comprehensive reviews on their application for POA prevention. This review begins with an overview of the pathogenesis of POA. Subsequently, it categorizes smart hydrogels based on their stimulus responsiveness, with a particular focus on summarizing design strategies and recent research advancements in temperature-responsive, photoactive, pH-sensitive, and ROS-responsive hydrogels for the prevention of POA. Finally, through assess the advantages of smart hydrogels in adhesion management, we are expecting to provide innovative perspectives for future research and clinical translation in this field.