School of Animal Science and Technology, Guangxi University, Nanning 530004, Guangxi, People's Republic of China.
School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea.
ACS Appl Bio Mater. 2021 Jul 19;4(7):5556-5565. doi: 10.1021/acsabm.1c00375. Epub 2021 Jun 16.
Neural electrodes have been developed for the diagnosis and treatment of stroke, sensory deficits, and neurological disorders based on the electrical stimulation of nerve tissue and recording of neural electrical activity. A low interface impedance and large active surface area for charge transfer and intimate contact between neurons and the electrode are critical to obtain high-quality neural signal and effective stimulation without causing damage to both tissue and electrode. In this study, a nanostructured poly(3,4-ethylenedioxythiophene) (PEDOT) coating with lots of long protrusions was created via a one-step electrochemical polymerization from a dichloromethane solution without any rigid or soft templates. The nanostructures on the PEDOT coating were basically formed by intertwined PEDOT nanofibers, which further enhanced the active surface area. The fuzzy PEDOT-modified microelectrodes exhibited an impedance as low as 1 kΩ at 1 kHz, which is much lower than those produced from aqueous 3,4-ethylenedioxythiophene (EDOT) solution, and it was comparable with PEDOT films or composites created from/with template materials. Also, more than 150 times larger charge storage capacity density was obtained compared to the unmodified microelectrode. An in vitro biocompatibility test performed on PC12 cells and primary cells suggested that the PEDOT coatings support cell adhesion, growth, and neurite extension. These results suggest the great potential of the nanostructured PEDOT coating as an electroactive and biosafe intimate contact between the implanted neural electrode and neurons.
神经电极已被开发出来，用于基于神经组织的电刺激和神经电活动的记录，以诊断和治疗中风、感觉缺失和神经紊乱。低的界面阻抗和大的活性表面积，用于电荷转移和神经元与电极之间的紧密接触，对于获得高质量的神经信号和有效的刺激而不造成组织和电极损伤是至关重要的。在这项研究中，通过一步电化学聚合，从二氯甲烷溶液中制备了具有大量长突起的纳米结构聚（3,4-亚乙基二氧噻吩）（PEDOT）涂层，而无需任何刚性或软模板。PEDOT 涂层上的纳米结构基本上是由相互交织的 PEDOT 纳米纤维形成的，这进一步增强了活性表面积。模糊的 PEDOT 修饰的微电极在 1 kHz 时表现出低至 1 kΩ的阻抗，远低于从水性 3,4-亚乙基二氧噻吩（EDOT）溶液中产生的阻抗，与从/用模板材料制备的 PEDOT 薄膜或复合材料相当。此外，与未修饰的微电极相比，获得了超过 150 倍的更大的电荷存储容量密度。在 PC12 细胞和原代细胞上进行的体外生物相容性测试表明，PEDOT 涂层支持细胞黏附、生长和突起延伸。这些结果表明，纳米结构 PEDOT 涂层作为植入式神经电极和神经元之间的电活性和生物安全的紧密接触具有巨大的潜力。
