Ultrasound-responsive Janus patch with mechanical anisotropy, pro-healing, and anti-adhesion properties for abdominal wall defect repair

Abdominal wall exhibits a complex anisotropic architecture with region-specific mechanical gradients, essential for maintaining biomechanical integrity during physiological deformations. However, most clinical patches possess isotropic structures and fail to meet the mechanical anisotropy requirements of abdominal wall. Herein, inspired by the hierarchical structure of abdominal wall, an innovative ultrasound-responsive Janus patch (JPLCL/ZnO) is designed by constructing a poly (2-methacryloyloxyethyl phosphorylcholine) (PMPC) coating on the top surface of a fibrous anisotropic patch (PLCL/ZnO) via multi-channel electrospinning and in situ photocuring technologies. By adjusting fiber orientation, our patch achieves tunable anisotropy ratios (1-14), matching the mechanical gradients of abdominal wall (1-9). The PMPC-coated side prevents tissue adhesion, while the anisotropic PLCL/ZnO side promotes directional cell growth and tissue regeneration under ultrasound stimulation. Moving toward clinical translation, we developed a large mammal defect model in pigs with abdominal wall resection. By integrating excellent mechanical anisotropy, pro-healing, anti-adhesion, and immune regulation properties, our JPLCL/ZnO patch demonstrates a significant advancement for abdominal wall defect repair.