Huang Zhiqiang, Sun Manman, Li Yanyi, Guo Zhenzhao, Li Hong
Department of Materials Science & Engineering, Jinan University, Guangzhou 510632, China.
J Mater Chem B. 2021 Mar 21;9(11):2656-2665. doi: 10.1039/d1tb00054c. Epub 2021 Feb 26.
Electrical signals are present in the extracellular spaces between neural cells. To mimic the electrophysiological environment for peripheral nerve regeneration, this study was intended to investigate how conductive graphene-based fibrous scaffolds with aligned topography regulate Schwann cell behavior in vitro via electrical stimulation (ES). To this end, randomly- and uniaxially-aligned polycaprolactone fibrous scaffolds were fabricated by electrospinning, followed by coating with reduced graphene oxide (rGO) via vacuum filteration. SEM revealed that rGO was successfully coated on the fibers without changing their alignment, and also brought about an improvement in mechanical properties and hydrophilicity. The electrical conductivity of the rGO-coated fibrous scaffold was up to 0.105 S m. When Schwann cells were seeded on the scaffolds and stimulated by 10 mV in vitro, it was found that either the alignment of the fibers or ES led to a higher level of proliferation and nerve growth factor (NGF) expression of Schwann cells. Further, ES at the aligned fibrous topography enhanced the expression of NGF, the proliferation of Schwann cells, and enhanced the cell migration rate by more than 60% compared to either ES or the oriented fibers alone. The application of exogenous electric cues mediated by templated biomaterials provides profound insights for nerve regeneration.
神经细胞之间的细胞外空间中存在电信号。为了模拟周围神经再生的电生理环境，本研究旨在探讨具有排列拓扑结构的导电石墨烯基纤维支架如何通过电刺激（ES）在体外调节雪旺细胞的行为。为此，通过静电纺丝制备了随机排列和单轴排列的聚己内酯纤维支架，然后通过真空过滤用还原氧化石墨烯（rGO）进行涂层。扫描电子显微镜显示，rGO成功地涂覆在纤维上，而不改变其排列，并且还改善了机械性能和亲水性。rGO涂层纤维支架的电导率高达0.105 S/m。当雪旺细胞接种在支架上并在体外以10 mV进行刺激时，发现纤维的排列或ES都会导致雪旺细胞更高水平的增殖和神经生长因子（NGF）表达。此外，与单独的ES或定向纤维相比，在排列的纤维拓扑结构下进行ES可增强NGF的表达、雪旺细胞的增殖，并使细胞迁移率提高60%以上。由模板化生物材料介导的外源性电信号的应用为神经再生提供了深刻的见解。
