Biomimetic lignin/poly(ionic liquids) composite hydrogel dressing with excellent mechanical strength, self-healing properties, and reusability

Trees are made of cellulose, hemicellulose and lignin linked by covalent bonds and supramolecular interactions. Among them, the lignin with three-dimensional structure plays a role in supporting the structure of the tree. Inspired by the nature of the tree, we have designed and synthesized a novel lignin/poly(ionic liquids) composite hydrogel dressing with excellent mechanical strength, self-healing properties, bactericidal activity, and antioxidant activity. This self-healing hydrogel dressing is obtained by the supramolecular interactions between the lignin/poly(ionic liquids) compounds. The introduction of lignin can effectively improve the mechanical properties of the hydrogel dressing. And the bactericidal poly (ionic liquid) modified on the lignin surface through covalent bonds endows this hydrogel dressing good antibacterial activity and self-healing properties. Wound healing model of rats and histomorphological evaluation results suggest that this hydrogel dressing promotes wound healing. Furthermore, the hydrogel dressing still maintains its excellent performances after simple high-temperature disinfection, and can be reused for many times.