Conductive Polymer Recording and Stimulation Electrodes

描述（由申请人提供）：提出了一种涂层，用于增强神经假体和电刺激疗法中电极的记录和刺激能力。该涂层基于导电聚合物，我们最近发现其支持的电荷注入水平至少是目前可用的最高电荷注入能力材料的六倍。提出了在聚合物与金属电极的粘附方面的具体创新，以及生物活性物质功能化聚合物的发展，以增强和稳定电极-神经界面。第一阶段的主要目标是：1)开发将聚合物涂层牢固附着在金属微电极表面的方法；2)在短期的长期研究中评估聚合物涂层电极的被动和功能性生物相容性。将采用几种促进粘附的策略对沉积在金属电极上的聚合物的粘附性、电荷注入能力和阻抗进行体外研究。在为期70天的体内研究中，粘附聚合物涂层将与穿透微电极一起用于组织和功能生物相容性评估。电极的记录能力将每周监测一次。聚合物涂层电极将受到电荷注入挑战，其最大可能是现有材料的四倍。电流脉冲时的体内电特性和非收缩神经元密度的定量组织学评估以及胶质包封的程度将被用作稳定性和生物相容性的测量。商业化：EIC实验室将通过提供电极涂层服务、开发交钥匙电沉积系统以及通过许可来实现该技术的商业化。相关性：导电聚合物涂层的应用包括用于脊髓损伤的皮质控制假体（脑机接口），用于视网膜色素变性或年龄相关性黄斑变性患者的视网膜假体，用于失明和耳聋患者的皮质内视觉和听觉假体，用于脊髓损伤的周围神经假体，以及用于刺激治疗的电极，如深部脑刺激（DBS）和心脏起搏器。神经假体正在被开发用于脊髓损伤、中风和疾病相关感觉缺陷的康复。目前正在开发以电刺激为基础的治疗方法，用于治疗神经退行性疾病，如原发性震颤和帕金森病，以及治疗癫痫、抑郁症和饮食失调。这些应用中有许多涉及到与神经系统的直接接口，并且需要比贵金属电极更具有记录和刺激能力的小面积电极。该提案解决了导电聚合物的电聚合膜作为电极涂层的发展，用于这些假体和治疗中使用的电极的记录和刺激需求。导电聚合物相对于竞争电极涂层的潜在优势是具有极高的电荷注入能力，并且有可能开发含有生物活性分子的涂层，以促进稳定和功能增强的神经电极界面的形成。

DESCRIPTION (provided by applicant): The development of coatings for enhancing the recording and stimulation capabilities of electrodes used in neural prostheses and electrical stimulation based therapies is proposed. The coatings are based on conducting polymers that we have recently found support charge- injection levels at least six times greater than is possible with the highest charge-injection capacity materials presently available. Specific innovations in terms of polymer adhesion to metal electrodes and the development of polymers functionalized with biologically active species for enhancing and stabilizing the electrode-nerve interface are proposed. The principal Phase I objectives are 1) to develop methods for the robust attachment of the polymer coatings to the surface of metal microelectrodes and 2) to evaluate, in a short chronic study, the passive and functional biocompatibility of polymer-coated electrodes. In vitro studies of the adhesion, charge-injection capabilities and impedance of polymers deposited on metal electrodes using several adhesion promoting strategies will be undertaken. Adherent polymer coatings will be used with penetrating microelectrodes for histologic and functional biocompatibility assessments in a 70 day in vivo study. The recording capabilities of the electrodes will be monitored weekly. Polymer-coated electrodes will be subjected to a charge-injection challenge at four times the maximum possible with present materials. In vivo electrical characteristics during current pulsing and quantitative histologic evaluation of non-pyknotic neuron densities and the extent of gliotic encapsulation will be used as measures of stability and biocompatibility. Commercial: EIC Laboratories will commercialize the technology by offering electrode coating services, the development of turn-key electrodeposition systems, and through licensing. Relevance: Applications of the conducting polymer coatings include cortical control prostheses (brain-machine interfaces) for the spinal cord injured, retinal prostheses for patients with retinitis pigmentosa or age-related macular degeneration, intracortical visual and auditory prostheses for blind and deaf patients, peripheral nerve prostheses for the spinal cord injured, and electrodes for stimulation-based therapies such as deep-brain-stimulation (DBS) and cardiac pacing. Neural prostheses are being developed for rehabilitation in spinal cord injury, stroke, and disease-related sensory deficits. Electrical-stimulation based therapies are being developed for the treatment of neuro- degenerative diseases such as essential tremor and Parkinson's, and the treatment of epilepsy, depression and eating disorders. Many of these applications involve a direct interface to the nervous system and require small-area electrodes with recording and stimulation capabilities beyond those available with noble metals. This proposal addresses the development of electro-polymerized films of conductive polymers as electrode coatings for the recording and stimulation needs of electrodes used in these prostheses and therapies. The potential advantages of the conductive polymers over competing electrode coatings are an exceptionally high charge-injection capacity and the possibility of developing coatings that contain biologically active molecules to promote the formation of a stable and functionally enhanced nerve-electrode interface.