Bioinspired hydrogel patch with controllable adhesion for soft tissue repair

Biomedical patches have demonstrated value in promoting soft tissue repair or anti-adhesion. Research tendency in this area focuses on developing more controllable patches to meet the complex clinical scenarios. Herein, inspired by the controllable adhesion of suction cups and the antifouling properties of eyeball surfaces, we propose an anisotropic patch with ‘revocable’ adhesion mechanisms. For the adhesive-side, the initial adhesion forces mainly rely on suction cup’s physical interactions to allow adequate position adjustment, followed by the reaction of N-hydroxysuccinimide ester group with the tissue for firm covalent bonding. This multi-adhesive mechanism enables the spatiotemporal control of adhesive behavior. In contrast, on the barrier-side, the highly hydrated surface derived from polyethylene glycol and polyvinyl alcohol hydrogels displays no affinity for tissue proteins, thus effectively preventing tissue adhesion. Moreover, the intrinsic pores and charges enable the adsorption of positively charged inflammatory factors, while the loaded drugs can release sustainably. In vivo experiments demonstrate the patch’s strong yet controllable adhesion, effective in reducing inflammation and promoting healing. This innovative design introduces a new paradigm of ‘revocable’ adhesion, offering significant clinical potential for soft tissue repair and adhesion prevention.