Kelly Adriona, Farid Nazar, Krukiewicz Katarzyna, Belisle Nicole, Groarke John, Waters Elaine M, Trotier Alexandre, Laffir Fathima, Kilcoyne Michelle, O'Connor Gerard M, Biggs Manus J
Centre for Research in Medical Devices, National University of Ireland, Galway H91 TK33, Ireland.
National Centre for Laser Applications, School of Physics, National University of Ireland, Galway H91 TK33, Ireland.
ACS Biomater Sci Eng. 2020 Mar 9;6(3):1449-1461. doi: 10.1021/acsbiomaterials.9b01321. Epub 2020 Feb 12.
The brain machine interface (BMI) describes a group of technologies capable of communicating with excitable nervous tissue within the central nervous system (CNS). BMIs have seen major advances in recent years, but these advances have been impeded because of a temporal deterioration in the signal to noise ratio of recording electrodes following insertion into the CNS. This deterioration has been attributed to an intrinsic host tissue response, namely, reactive gliosis, which involves a complex series of immune mediators, resulting in implant encapsulation via the synthesis of pro-inflammatory signaling molecules and the recruitment of glial cells. There is a clinical need to reduce tissue encapsulation in situ and improve long-term neuroelectrode functionality. Physical modification of the electrode surface at the nanoscale could satisfy these requirements by integrating electrochemical and topographical signals to modulate neural cell behavior. In this study, commercially available platinum iridium (Pt/Ir) microelectrode probes were nanotopographically functionalized using femto/picosecond laser processing to generate laser-induced periodic surface structures (LIPSS). Three different topographies and their physical properties were assessed by scanning electron microscopy and atomic force microscopy. The electrochemical properties of these interfaces were investigated using electrochemical impedance spectroscopy and cyclic voltammetry. The in vitro response of mixed cortical cultures (embryonic rat E14/E17) was subsequently assessed by confocal microscopy, ELISA, and multiplex protein array analysis. Overall LIPSS features improved the electrochemical properties of the electrodes, promoted cell alignment, and modulated the expression of multiple ion channels involved in key neuronal functions.
脑机接口（BMI）描述了一组能够与中枢神经系统（CNS）内的可兴奋神经组织进行通信的技术。近年来，BMI取得了重大进展，但由于记录电极插入CNS后信噪比随时间下降，这些进展受到了阻碍。这种下降归因于内在的宿主组织反应，即反应性胶质增生，它涉及一系列复杂的免疫介质，通过促炎信号分子的合成和胶质细胞的募集导致植入物被包裹。临床上需要在原位减少组织包裹并改善长期神经电极功能。通过整合电化学和形貌信号来调节神经细胞行为，在纳米尺度上对电极表面进行物理修饰可以满足这些要求。在本研究中，使用飞秒/皮秒激光加工对市售的铂铱（Pt/Ir）微电极探针进行纳米形貌功能化，以产生激光诱导的周期性表面结构（LIPSS）。通过扫描电子显微镜和原子力显微镜评估了三种不同的形貌及其物理性质。使用电化学阻抗谱和循环伏安法研究了这些界面的电化学性质。随后通过共聚焦显微镜、酶联免疫吸附测定（ELISA）和多重蛋白质阵列分析评估了混合皮质培养物（胚胎大鼠E14/E17）的体外反应。总体而言，LIPSS特征改善了电极的电化学性质，促进了细胞排列，并调节了参与关键神经元功能的多个离子通道的表达。
