Multifunctional conductive stem cell delivery hydrogel combined with low-frequency pulsed electromagnetic fields for spinal cord injury repair

A injectable, self-healing, magnetic and conductive hydrogel was synthesized for delivering NSCs to repair SCI. Combined with LPEMFs, this conductive hydrogel alleviated the inflammation and promoted functional neurogenesis.which it is valuable for the clinical transformationof repairing SCI. • An injectable, self-healing, magnetic and conductive hydrogel was synthesized for delivering NSCs to repair SCI. • Combined with LPEMFs, this multifunctional hydrogel alleviated the inflammation and promoted functional neurogenesis. • A multifunctional strategy composed of conductive hydrogel and LPEMFs was proposed and was valuable for the clinical translation. Spinal cord injury (SCI) is a severe traumatic disease for which no satisfying treatment is available. The severe inflammatory reactions and poor endogenous regenerative capacity cause difficulty in functional recovery. Neural stem cells (NSCs) transplantation is currently a promising treatment for repairing SCI. However, there is a lack of effective ways to improve the survival rates of NSCs and promote the neuron differentiation rates of NSCs. Conductive hydrogel can mimic environment which is suitable for neurodevelopment. Low-frequency pulsed electromagnetic fields (LPEMFs) have the advantages of safety, non invasiveness, and tissue repair, making it a potential method of repairing SCI. In this study, an injectable, self-healing magnetic, and conductive hydrogel was synthesized to carry out NSCs with LPEMFs for repairing SCI. In vitro experiments, under the treatment of LPEMFs and conductive hydrogel, the microglia tend to polarize into M2 phenotype, rather than M1 phenotype. Meanwhile, NSCs tend to differentiate into neuronal direction. In SCI model, conductive hydrogel loaded with NSCs combined with LPEMFs can promote functional recovery, through reducing inflammation and promoting neuron differentiation of NSCs. This study provides a novel NSCs transplantation strategy combined with physical interventions for SCI treatment, which brings a new desire to repair SCI.