Mimicking soft tissue mechanical properties and the high conductivity required for electrical transmission in the native spinal cord is critical in nerve tissue regeneration scaffold designs. However, fabricating scaffolds of high conductivity, tissue-like mechanical properties, and excellent biocompatibility simultaneously remains a great challenge. Here, a soft, highly conductive, biocompatible conducting polymer hydrogel (CPH) based on a plant-derived polyphenol, tannic acid (TA), cross-linking and doping conducting polypyrrole (PPy) chains is developed to explore its therapeutic efficacy after a spinal cord injury (SCI). The developed hydrogels exhibit an excellent electronic conductivity (0.05–0.18 S/cm) and appropriate mechanical properties (0.3–2.2 kPa), which can be achieved by controlling TA concentration. In vitro, a CPH with a higher conductivity accelerated the differentiation of neural stem cells (NSCs) into neurons while suppressing the development of astrocytes. In vivo, with relatively high conductivity, the CPH can activate endogenous NSC neurogenesis in the lesion area, resulting in significant recovery of locomotor function. Overall, our findings evidence that the CPHs without being combined with any other therapeutic agents have stimulated tissue repair following an SCI and thus have important implications for future biomaterial designs for SCI therapy.

中文翻译：

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单宁酸交联掺杂的软导电聚合物水凝胶修复脊髓损伤

在神经组织再生支架设计中，模仿软组织的机械特性和在天然脊髓中进行电传输所需的高电导率至关重要。然而，同时制造具有高电导率，类似组织的机械性能和优异的生物相容性的支架仍然是巨大的挑战。在这里，开发了一种基于植物衍生的多酚，鞣酸（TA），交联和掺杂的导电聚吡咯（PPy）链的柔软，高导电性，生物相容性的导电聚合物水凝胶（CPH），以探索其在脊柱后的治疗功效脊髓损伤（SCI）。所开发的水凝胶具有出色的电子传导性（0.05–0.18 S / cm）和适当的机械性能（0.3–2.2 kPa），这可以通过控制TA浓度来实现。在体外，具有较高电导率的CPH可以加速神经干细胞（NSC）向神经元的分化，同时抑制星形胶质细胞的发育。在体内，CPH具有较高的电导率，可以激活病变区域的内源性NSC神经发生，从而显着恢复运动功能。总体而言，我们的发现证明，不与任何其他治疗剂联合使用的CPH在SCI后可刺激组织修复，因此对于SCI治疗的未来生物材料设计具有重要意义。