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.

A change in strain partitioning and microscale failure mechanisms in dual-phase (DP) steel was found when both the morphology and distribution of martensite were altered compared to a banded DP steel grade benchmarked against a specific commercial DP grade. To achieve a DP microstructure with equiaxed and well-dispersed martensite, the concept of segregation neutralisation was utilised, where the ratio of Mn to Si elements was decreased (from 7.4 to 0.3) to neutralise the effect of Mn segregation on generating the banded martensite. A combination of micromechanical modelling simulations and in-situ notch tensile testing (within an SEM) was employed to compare the micro strain field and void formation rate between the segregation-neutralised and the benchmark grades. The benchmark grade showed extensive void coalescence along the direction of shear bands in the tensile sample after the average tensile strain of 30%. In contrast, no void coalescence was observed in the segregation-neutralised DP steel even at the average tensile strain of 80% just before failure. As a result, post-uniform elongation in the segregation-neutralised grade increased to 63.3%, compared to 30.1% in the benchmark grade.