A strong, tough, fatigue-resistant, and biocompatible biogel via lignin-induced multiscale energy dissipation mechanisms

Replicating the unique combination of biocompatibility and mechanical strength found in biological tissues within synthetic biomass materials remains a critical challenge in advanced materials engineering. In this study, a synergistic “lignin/solvent-induced noncovalent enhancement” strategy was adopted to precisely regulate the network topology through lignin/glycerol solvent substitution in a chitosan/gelatin dual-network matrix. Following glycerol solvent exchange, the polymer–polymer interactions are intensified, inducing the formation of a homogeneous and robust polymer network and completing the network reconstruction. The sulfonic acid and hydroxyl moieties in sulfonated lignin act as dynamic cross-linking points within the chitosan/gelatin network. These functional groups mediate interfacial electrostatic and hydrogen bonding interactions, thereby constructing multiple networks that exhibit superior energy dissipation capacity under deformation through reversible bond rupture and reformation mechanisms. This strategy not only breaks through the mechanical limits of conventional dual-network biogels (tensile strength, 4.35 ± 0.08 MPa; compressive strength, 66.11 ± 3.90 MPa) but also confers excellent biocompatibility and anti-fatigue properties to the material. Such a biomass-derived gel provides a promising route toward the development of high-performance load-bearing materials.

Graphical Abstract