Dynamic reversible disulfide bonds hydrogel of thiolated galactoglucomannan/cellulose nanofibril with self-healing property for protein release

In the context of sustainability transition to effectively utilize renewable biopolymers in building functional materials, we report a dynamic reversible nanocomposite hydrogel via thiolated galactoglucomannan (GGMSH) and TEMPO-oxidized cellulose nanofibrils (T-CNF) by deploying a UV-triggered thiol-disulfide exchange reaction. By adjusting the compositional content of GGMSH, the viscoelastic properties of the hydrogel precursors are tuneable and the crosslinking degree of disulfide bonds in these hydrogels dictates their mechanical properties upon UV irradiation. The nanocomposite hydrogels of GGMSH/T-CNF demonstrate robust self-healing properties, attributed to the dynamically reversible disulfide bonds and strong hydrogen bonds between T-CNF and GGMSH. For the hydrogel system of GGMSH/T-CNF/bovine serum albumin (BSA), the swelling behaviour of nanocomposite hydrogels largely dominated the release of BSA out of the hydrogels, suppressing the effect of redox-responsive stimuli with the addition of glutathione. Still, the cytotoxicity test proved a low cytotoxicity of the nanocomposite hydrogel and provided promising reference value to exploit this class of natural polymer-based hydrogel systems in biomedical applications.