A Bioinspired Injectable, Adhesive, and Self‐Healing Hydrogel with Dual Hybrid Network for Neural Regeneration after Spinal Cord Injury

Hydrogel‐based regenerated scaffolds show promise as a platform for neural regeneration following spinal cord injury (SCI). Nevertheless, the persistent problem of poor mechanical strength and limited integration with the host tissue still exists. In this study, a bioinspired hydrogel with highly sophisticated features for neural regeneration after SCI is developed. The hydrogel is composed of dihydroxyphenylalanine (DOPA)‐grafted chitosan and a designer peptide, offering a unique set of qualities such as being injectable, having self‐healing abilities, and adhering to tissues. Compared to conventional hydrogels, this hydrogel ensures a significant promotion of immune response modulation and axon regrowth while featuring synapse formation of various neurotransmitters and myelin regeneration. Subsequently, functional recoveries are enhanced, including motor function, sensory function, and particularly bladder defect repair. These positive findings demonstrate that the hydrogel has great potential as a strategy for repairing SCI. Moreover, the versatility of this strategy goes beyond neural regeneration and holds promise for tissue regeneration in other contexts. Overall, this proposed hydrogel represents an innovative and multifaceted tool for engineering structures in the biomedical field. A novel hydrogel with a double‐network architecture is created from dihydroxyphenylalanine (DOPA)‐grafted chitosan and a designer self‐assembly peptide. Its strong tissue adhesion facilitates excellent integration in the host and demonstrates self‐healing feature. The novel hydrogel demonstrates a strong capability of promoting exuberant neural regeneration after spinal cord injury and consequently promotes sensory and motor functions, particularly protecting the urinary system.