On-Demand Degradable Thiol-Maleimide PEG Hydrogels as Abrasion-Free Adhesives

Abstract

Hydrogels are promising materials for adhesive applications due to their ideal physicochemical properties; however, balancing robust mechanical properties with on-demand degradability remains a significant challenge. In this report, we synthesized a series of on-demand degradable semi-interpenetrating polymer network hydrogels as a potential adhesive material. The core of our design utilizes thiol-maleimide-modified poly(ethylene glycol) as tetra-valent crosslinker. Through copolymerization with acrylamide in the presence of biocompatible linear polymers—specifically poly(vinyl alcohol) and gelatin—we prepared mechanically stable hydrogels with a high swelling capacity exceeding 800% and negligible cytotoxicity. Notably, the resulting gels can be firmly attached to porcine skin but are easily removed through a gentle degradation process using a fabric immersed in L-cysteine methyl ester hydrochloride. These findings highlight the potential of these degradable hydrogels to provide a balance of secure adhesion and easy removal.