Restoring neuronal iron homeostasis revitalizes neurogenesis after spinal cord injury

Spinal cord injury (SCI) can lead to iron overloading and subsequent neuronal ferroptosis, which hinders the recovery of locomotor function. However, it is still unclear whether the maintenance of neuronal iron homeostasis enables to revitalize intrinsic neurogenesis. Herein, we report the regulation of cellular iron homeostasis after SCI via the chelation of excess iron ions and modulation of the iron transportation pathway using polyphenol-based hydrogels for the revitalization of intrinsic neurogenesis. The reversed iron overloading can promote neural stem/progenitor cell differentiation into neurons and elicit the regenerative potential of newborn neurons, which is accompanied by improved axon reinnervation and remyelination. Notably, polyphenol-based hydrogels significantly increase the neurological motor scores from similar to 8 to 18 (out of 21) and restore the transmission of sensory and motor electrophysiological signals after SCI. Maintenance of iron homeostasis at the site of SCI using polyphenol-based hydrogels provides a promising paradigm to revitalize neurogenesis for the treatment of iron accumulation-related nervous system diseases.