**Abstract:** A recent study by the spinal surgery team from the Brain Disease Center at the Third Affiliated Hospital of Sun Yat-sen University, published in *Science Advances* (a top-tier interdisciplinary academic journal), presents a novel strategy for spinal cord injury (SCI) repair using a tissue-integrating hydrogel. The spinal cord, a critical component of the central nervous system, is prone to severe neurological impairments following injury, characterized by high rates of disability and mortality, and significant challenges in treatment. This study introduces a supramolecular hydrogel composed of dopamine-grafted hyaluronic acid (HADA) combined with a functional short peptide (HRR), designed to manipulate extracellular matrix (ECM) deposition and enhance neural regeneration and repair. The hydrogel is engineered to load and slowly release the neurotrophic factor NT3 and the anti-inflammatory drug curcumin (Cur). This combination not only improves the microenvironment for axonal regeneration but also promotes the survival of neurons at both ends of the injury site. A key finding is the ability of the HADA/HRR hydrogel to modulate the behavior of PDGFRβ+ cells, which are primarily responsible for the formation of fibrotic scars post-injury. In the hydrogel intervention group, PDGFRβ+ cells migrated in a parallel alignment towards the hydrogel, facilitating the formation of a parallel-structured ECM that guides axonal growth rather than forming a dense, irregular scar. The sustained release of NT3 and Cur further enhanced this ECM remodeling effect. Neurons and axons exhibit significant structural and functional heterogeneity, and the re-establishment of specific neural connections is crucial for functional recovery. The study demonstrates that the HADA/HRR+NT3/Cur hydrogel promotes the survival of interneurons at the injury boundary. These activated interneurons act as relay stations, forming heterogeneous synaptic structures with the severed ascending and descending nerve fibers, thereby achieving "precise" neural reconnections. Additionally, the hydrogel enhanced the survival of V2a neurons at both ends of the injury, which established excitatory synaptic connections with the spinal cord's conducting tracts. This finding underscores the importance of activating and integrating specific relay neurons into the neural network for functional recovery. The research also establishes a positive correlation between the number of relay neurons and the recovery of motor function, providing a potential therapeutic target for SCI repair. The effectiveness of the hydrogel strategy was validated in a canine model of partial spinal cord transection, demonstrating its potential for clinical application. This study not only offers a promising approach to reshaping the microenvironment after SCI but also deepens the understanding of the role of specific neuronal subpopulations in neural structure reconstruction. By identifying these key mechanisms, the research provides a theoretical foundation for advancing functional recovery in SCI patients and paves the way for the development of regenerative neurorepair technologies. The study was led by Professor Limin Rong, a leading expert in orthopedics, and Dr. Liumin He, a researcher in orthopedics. The first authors are Master's students Zan Tan, Longyou Xiao, and Junwu Ma from the Department of Spinal Surgery. The research was supported by several grants, including the National Natural Science Foundation of China (32271417, 32071354, U22A20297), the Guangdong-Hong Kong Joint Innovation Grant under the Guangdong Provincial Science and Technology Innovation Strategy (2021A0505110007), the Guangdong Provincial Natural Science Foundation - Outstanding Youth Project (022B1515020083), and the Guangzhou Key Research and Development Program (202206060002, 202206060003). **Keywords:** Spinal Cord Injury, Hydrogel, Neural Regeneration, Extracellular Matrix, Relay Neurons, Functional Recovery, Biomedical Engineering, Neurotrophic Factors, Anti-Inflammatory Drugs, Clinical Application, Canine Model.