Immuno-engineered conductive hydrogels: Bridging neural signaling and microenvironmental remodeling for neural repair

Nervous system injuries and diseases present formidable regenerative challenges, largely due to hostile inflammatory microenvironments that impede endogenous repair mechanisms. Conductive nanocomposite hydrogels have emerged as a transformative class of immuno-engineered biomaterials designed to actively overcome these barriers. Beyond providing electroactive scaffolds to restore neural signaling, these advanced platforms integrate functional nanomaterials (e.g., carbon-based, MXene, and conductive polymers) within biocompatible polymer networks to facilitate targeted immunomodulation. Their core scientific significance lies in their synergistic capacity to simultaneously scavenge pathological reactive oxygen species (ROS) and steer macrophage polarization towards a pro-regenerative phenotype, thereby reprogramming the inhibitory injury niche into a permissive, pro-healing milieu. This review systematically elucidates the design principles spanning crosslinking strategies to nanomaterial selection that underpin these dual functions. We critically summarize recent breakthroughs in applying these multifunctional hydrogels to treat spinal cord injury, traumatic brain injury, stroke, and peripheral nerve defects, where they demonstrate enhanced functional recovery. By bridging the fields of conductive biomaterials and immunomodulation, this work not only surveys the state-of-the-art but also provides a unified framework for developing next-generation therapeutic platforms that couple bioelectronic cues with precise immune modulation, offering a novel paradigm for neural regeneration medicine.