Impedance optimization by electrophoretic deposition of laser-generated colloidal nanoparticles on the surface of platinum-iridium macroelectrodes for deep brain stimulation and platinum-tungsten microelectrodes for recording of neural activity

通过在用于深部脑刺激的铂-铱大电极和用于记录神经活动的铂-钨微电极表面上电泳沉积激光产生的胶体纳米颗粒来优化阻抗

• 批准号: 201925000
• 负责人: Professor Dr.-Ing. Stephan Barcikowski
• 金额: --
• 依托单位: Lehrstuhl für Technische Chemie I
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/201925000?language=en
• 关键词: Impedance; optimization; electrophoretic; deposition; laser

Electrodes are routinely used for chronic stimulation or recording of neuronal activity during therapeutic or diagnostic neurosurgical interventions. The quality of these electrodes is critically affected by their impedance. While low and stable impedance is needed for reduced energy consumption during chronic deep brain stimulation (DBS), high impedance is required for recording of neuronal activity in order to achieve good signal to noise ratios. In this project we aim to examine if coatings composed of platinum and tungsten oxide nanoparticles (NP) can be used to tune the impedance and to elucidate a systematic correlation between coating properties (surface coverage, particle size, material) and electrophysical characteristics of the electrodes in vitro and in vivo. During the first term of our joint proposal we successfully developed a coating process based on electrophoretic deposition (EPD) using laser-fabricated, ligand-free nanoparticles and determined in vitro that impedance positively correlates with nanoparticle surface coverage, surface charge and surface oxidation of the new electrodes. Long term in vivo deep brain stimulation experiments in rats revealed that coating the electrodes with Pt NP significantly stabilizes impedance. Furthermore, the coatings endured mechanical tear and did not negatively affect biocompatibility. During the second phase of our proposal, we intend to explore the correlation between the initial impedance of the electrode in vitro and the subsequent alteration of impedance in vivo. We will use coating parameters optimized for low impedance, clinically relevant for chronic stimulation. Furthermore, long term in vitro stimulation experiments will be used to explore whether reported changes in impedance with time originate from the electrode alone or they are due to electrode-tissue interactions. In addition to PtIr electrodes, the project will further focus on PtW recording electrodes, which will be coated with tungsten oxide and platinum NP for high impedance. Consecutive in vivo recording experiments will verify whether the corresponding coating can improve the quality of the neuronal signal, i.e., the signal to noise ratio. An important issue during in vivo applications of coated is the stability of the coating. Therefore, detailed examinations of the binding state of the nanoparticles on the electrode as well as thorough evaluations of biocompatibility will be conducted. The project will be complemented by particle-based simulations of the EPD process in order to more precisely correlate electrode properties with coating parameters.

在治疗或诊断性神经外科干预期间，电极通常用于慢性刺激或记录神经元活性。这些电极的质量受到阻抗的严重影响。虽然在慢性深脑刺激（DBS）期间降低能量消耗需要低和稳定的阻抗，但记录神经元活动需要高阻抗才能实现良好的信号与噪声比。在该项目中，我们旨在检查由铂和氧化二氧化碳纳米颗粒（NP）组成的涂层是否可以用于调整阻抗并阐明涂层（表面覆盖，粒径，材料）和电dododes odedes ofdodes the Electrodes的涂层（表面覆盖，粒径，物质）之间的系统相关性。在联合提案的第一项中，我们使用激光制作的，无配体的纳米颗粒成功开发了基于电泳沉积（EPD）的涂层过程，并确定了在体外，该过程与纳米颗粒表面覆盖率，表面电荷和新电气的表面氧化呈阳性相关。长期的体内深脑刺激实验表明，用Pt NP涂层电极可显着稳定阻抗。此外，涂料忍受了机械撕裂，不会对生物相容性产生负面影响。在提案的第二阶段，我们打算探索电极在体外的初始阻抗与随后在体内阻抗的改变之间的相关性。我们将使用针对低阻抗进行优化的涂料参数，与慢性刺激相关。 此外，将使用长期的体外刺激实验来探索报告的阻抗的变化是否源自电极，还是由于电极组织相互作用而引起的。除PTIR电极外，该项目还将进一步关注PTW记录电极，该电极将用氧化钨和铂NP涂覆，以实现高阻抗。连续的体内记录实验将验证相应的涂层是否可以改善神经元信号的质量，即信号与噪声比。涂层的体内应用过程中的一个重要问题是涂层的稳定性。因此，将对电极对纳米颗粒的结合状态进行详细检查以及对生物相容性的彻底评估。该项目将通过基于粒子的EPD过程的模拟来互补，以便更精确地将电极性能与涂层参数相关。