Gelatin methacrylate-based bioadhesive hybrid hydrogels by photoclick thiol-ene chemistry

Gelatin methacrylate (GMA) has attracted extensive research interest in tissue engineering applications owing to its photocurable and biocompatible properties. However, GMA hydrogels exhibit relatively poor bioadhesion, mechanical properties, and printability, which limits their biomedical application. In particular, the efficacy of gelatin-based systems crosslinked by various methods have highlighted their limitations with respect to speed of polymerization, adhesion strength, and elasticity. Herein, we have developed three GMA-based novel photocrosslinkable bioadhesive hybrid hydrogel systems: two using thiol-ene click chemistry (comprising thiolated poly(ethylene glycol) polymer and thiolated natural pectin polysaccharide) and one using addition polymerization (comprising dopamine methacrylate). The thiol-ene crosslinked hydrogels exhibited superior flexibility, and bioadhesion properties, improved 3D printing accuracy, and excellent cell viability when compared to photo crosslinked hydrogels from acrylated precursors. The developed hydrogels can be potentially applied as tissue adhesives and sealants due to their rapid photocrosslinking characteristics with gelation time within 3 sec. • Development of rapidly protocrosslinkable bioadhesive hybrid hydrogel systems. • Two crosslinking mechanisms used, thiol-ene click chemistry and addition polymerization. • Biocompatible and printable hydrogels with tuneable physicochemical properties.