Robust hydrogel adhesives for emergency rescue and gastric perforation repair

Development of biocompatible hydrogel adhesives with robust tissue adhesion to realize instant hemorrhage control and injury sealing, especially for emergency rescue and tissue repair, is still challenging. Herein, we report a potent hydrogel adhesive by free radical polymerization of N-acryloyl aspartic acid (AASP) in a facile and straightforward way. Through delicate adjustment of steric hindrance, the synergistic effect between interface interactions and cohesion energy can be achieved in PAASP hydrogel verified by X-ray photoelectron spectroscopy (XPS) analysis and simulation calculation compared to poly (N-acryloyl glutamic acid) (PAGLU) and poly (N-acryloyl amidomalonic acid) (PAAMI) hydrogels. The adhesion strength of the PAASP hydrogel could reach 120 kPa to firmly seal the broken organs to withstand the external force with persistent stability under physiological conditions, and rapid hemostasis in different hemorrhage models on mice is achieved using PAASP hydrogel as physical barrier. Furthermore, the paper-based Fe(3+) transfer printing method is applied to construct PAASP-based Janus hydrogel patch with both adhesive and non-adhesive surfaces, by which simultaneous wound healing and postoperative anti-adhesion can be realized in gastric perforation model on mice. This advanced hydrogel may show vast potential as bio-adhesives for emergency rescue and tissue/organ repair.