Anisotropic Janus Hydrogel Patch for Abdominal Wall Regeneration and Postoperative Antiadhesion

The reconstruction of abdominal wall defects and prevention of postoperative visceral adhesions remain critical clinical challenges in managing abdominal trauma. Here, a highly bioactive macroporous hyaluronic acid hydrogel was firmly integrated onto the upper layer of the poly(vinyl alcohol) hydrogel through dynamic borate ester bonds to construct the biomimetic repair patch (PHA). The anisotropic backbone prepared based on a top-down solvent exchange strategy achieved strong mechanical strength (2.69 MPa), excellent elastic deformation (369.73%), and biomimetic structure of asymmetric porous surfaces with upper (79.62 μm) and lower (0.63 μm) pore sizes. The in vivo abdominal wall defect repair model demonstrated that the asymmetric porous structure of the PHA patch simultaneously enables in situ regeneration of abdominal wall tissues and suppression of visceral adhesions. Therefore, the design of the PHA patch opens a new avenue for developing an integrated biomimetic abdominal wall material, holding significant practical implications for enhancing the clinical treatment efficacy of abdominal wall defects.