Graphene, as a highly conducting material, incorporated into silk fibroin (SF) substrates is promising to fabricate an electroactive flexible scaffold toward neural tissue engineering. It is well known that aligned morphology could promote cell adhesion and directional growth. The purpose of this study was to develop aligned conductive scaffolds made of graphene and SF (G/SF) by electrospinning technique for neural tissue engineering applications. The physicochemical characterization of scaffolds revealed that the mechanical and electrochemical property of aligned G/SF scaffolds continually raised with the increasing contents of graphene (A0% G/SF, A1% G/SF, A2% G/SF, and A3% G/SF), but the mechanical property descended when the graphene concentration reached to 4% (the A4% G/SF group). The results of the cell experiment in vitro indicated that all the aligned G/SF scaffolds were no neurotoxic to primary cultured spinal cord neurons. In addition, the neurite elongation in all aligned groups was significantly enhanced by the upregulation of Netrin‐1 expression compared to them in the control group. Thus, A3% G/SF scaffolds not only possessed the optimal property based on the mechanical and electrochemical performances but also displayed the beneficial capability to neurite outgrowth, which might perform a suitable candidate to successfully scaffold electrically active tissues during neural regeneration or engineering.

中文翻译：

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对齐石墨烯/丝素蛋白导电纤维支架，用于指导大鼠脊髓神经元的神经突向外生长

石墨烯作为一种高导电材料，掺入丝素蛋白 (SF) 基材中，有望为神经组织工程制造电活性柔性支架。众所周知，排列的形态可以促进细胞粘附和定向生长。本研究的目的是通过静电纺丝技术开发由石墨烯和 SF (G/SF) 制成的对齐导电支架，用于神经组织工程应用。支架的理化表征表明，随着石墨烯含量的增加（A0% G/SF、A1% G/SF、A2% G/SF 和 A3% G/ SF），但当石墨烯浓度达到 4%（A4% G/SF 组）时，力学性能下降。体外细胞实验结果表明，所有对齐的G/SF支架对原代培养的脊髓神经元均无神经毒性。此外，与对照组相比，Netrin-1 表达的上调显着增强了所有对齐组的神经突伸长。因此，A3% G/SF 支架不仅具有基于机械和电化学性能的最佳性能，而且还显示出有益的神经突生长能力，这可能是在神经再生或工程过程中成功支架电活性组织的合适候选者。与对照组相比，Netrin-1 表达的上调显着增强了所有对齐组的神经突伸长率。因此，A3% G/SF 支架不仅具有基于机械和电化学性能的最佳性能，而且还显示出有益的神经突生长能力，这可能是在神经再生或工程过程中成功支架电活性组织的合适候选者。与对照组相比，Netrin-1 表达的上调显着增强了所有对齐组的神经突伸长率。因此，A3% G/SF 支架不仅具有基于机械和电化学性能的最佳性能，而且还显示出有益的神经突生长能力，这可能是在神经再生或工程过程中成功支架电活性组织的合适候选者。