Multifunctional Conductive and Electrogenic Hydrogel Repaired Spinal Cord Injury via Immunoregulation and Enhancement of Neuronal Differentiation.

Spinal cord injury (SCI) is a refractory neurological disorder. Due to the complex pathological processes, especially the secondary inflammatory cascade and the lack of intrinsic regenerative capacity, it is difficult to recover neurological function after SCI. Meanwhile, simulating the conductive microenvironment of the spinal cord promises to reconstruct electrical neural signal transmission interrupted by SCI and facilitates the neural repair. A double-crosslinked conductive hydrogel (BP@Hydrogel) containing black phosphorus nanoplates (BP) is synthesized. When placed in a rotating magnetic field (RMF), the BP@Hydrogel can generate stable electrical signals and exhibit electrogenic characteristic. In vitro, the BP@Hydrogel shows satisfactory biocompatibility and can alleviate the activation of microglia. When placed in the RMF, it enhances the anti-inflammatory effects. Meanwhile, the wireless electrical stimulation promotes the differentiation of neural stem cells (NSCs) to neurons, which is associated with the activation of the PI3K/AKT pathway. In vivo, the BP@Hydrogel is injectable and could elicit behavioral and electrophysiological recovery in complete transected SCI mice by alleviating the inflammation and facilitating endogenous NSCs to form functional neurons and synapses under the RMF. The present research develops a multifunctional conductive and electrogenic hydrogel for SCI repair by targeting multiple mechanisms including immunoregulation and enhancement of neuronal differentiation. This article is protected by copyright. All rights reserved.