Coatings for Biostable Chronic Neural Prostheses

用于生物稳定慢性神经假体的涂层

• 批准号: 7272554
• 负责人: HILTON G PRYCE LEWIS
• 金额: $ 40.44万
• 依托单位: GVD CORPORATION
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-15 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7272554
• 关键词: Achievement; Address; Adhesions; Animals; Area; Arts; Biocompatible; Biocompatible Coated Materials; Biological; Blindness; Cells; Characteristics; Chemicals; Chronic; Class; Communities; Complex; Condition; Defect; Deposition; Depth; Development; Device Designs; Device or Instrument Development; Devices; Dimensions; Electrodes; Ensure; Environment; Epilepsy; Exhibits; Foreign Bodies; Funding; Future; Goals; Growth; Immersion Investigative Technique; Implant; In Vitro; Investigation; Lead; Manufacturer Name; Mechanics; Mental Depression; Miniaturization; Modification; Neurologic; Neurons; Numbers; Object Attachment; Oryctolagus cuniculus; Parkinson Disease; Performance; Phase; Physiological; Pliability; Polymers; Polytetrafluoroethylene; Process; Property; Prosthesis; Range; Research; Research Personnel; Resistance; Saline; Screening procedure; Series; Shapes; Silicones; Solutions; Solvents; Structure; Surface; System; Techniques; Technology; Testing; Thinness; Time; Tissues; United States National Institutes of Health; Universities; Utah; Work; base; biomaterial compatibility; brain tissue; comparative; copolymer; implantation; improved; in vivo; nervous system disorder; neural prosthesis; parylene C; performance tests; polytetrafluoroethylene-silicone; programs; relating to nervous system; response; scale up; size; success; tool; vapor; voltage

DESCRIPTION (provided by applicant): The miniaturization of neuroprosthetic technology has led to an urgent need for insulating coatings that retain their biocompatibility and stability over long periods. Initiated Chemical Vapor Deposition (iCVD) is an attractive alternative to applying polymers using solvent-based techniques such as dip/spray and curing. iCVD has the benefits of thinness, conformality (conforms very well to complex shapes) and high purity. Materials that can be produced include: fluoropolymers, which have excellent resistively and inertness to long-term implantation, and silicones, which have excellent flexibility, adhesion, and biocompatibility. The goal of this work is to combine these characteristics into a composite material that satisfies all of the requirements of chronic implantation in a neurological environment. In Phase I, the feasibility of combining silicones and fluoropolymers was demonstrated using two approaches: (1) a bi-layer comprising silicone as a base layer and fluoropolymer as a surface layer, and (2) a fluorinated silicone copolymer. Coatings were produced, tested for mechanical durability, stability, and resistively, and compared against Parylene-C, a commercially available vapor-deposited coating. Although both approaches performed comparably to Parylene-C in insulating resistance, the bi-layer showed better adhesion to a wide range of substrates and superior soak stability. Based on these results, and the excellent long-term stability exhibited by other iCVD silicone coatings (2+ years under soak without any loss in resistively), the bi-layer structure was selected for further development in Phase II. In Phase II, the range of compositions used in the bi-layer structure will be expanded. The process for producing silicone coatings will be scaled up to allow a multitude of complex, three-dimensional devices to be coated. More rigorous, long-term testing will be performed using real-world device components as substrates, and the performance of GVD's coatings will be compared against state-of-the-art commercial coatings. In addition to mechanical and electrical performance testing, compatibility to nerve cells and tissue will be systematically examined and animal implantation studies performed. Phase II investigations will also address how these new coating materials can be biologically modified to mitigate the brain tissue foreign-body response. The ultimate goal of this work is to achieve single step encapsulation of three-dimensional neural probe arrays and of neural prosthetic assemblies. The development of a stable, durable, biocompatible insulating coating under this Phase II will enable that goal to be achieved. The success of this Phase II will allow GVD to offer to researchers & manufacturers a proven, effective tool for the insulation and encapsulation of neuroprosthetic devices. The coating developed under this work will provide greater flexibility in the design of devices, the choice of materials used, and the minimum dimensions which can be achieved in neuroprosthetic devices. Therapeutically, the coating will perform better when implanted and provide safe and effective protection of devices in chronic applications. The long-term impact will be to de-bottleneck the development of devices and accelerate their proliferation as treatments for neurological disorders.

描述（由申请人提供）：神经假体技术的微型化导致迫切需要隔离涂料，以保留长时间的生物相容性和稳定性。引发化学蒸气沉积（ICVD）是使用基于溶剂的技术（例如浸出/喷雾剂和固化）应用聚合物的有吸引力的替代品。 ICVD具有薄，整合性（非常适合复杂形状）和高纯度的好处。可以生产的材料包括：氟聚合物对长期植入具有极好的电阻和惰性，以及具有良好灵活性，粘附和生物相容性的硅树脂。这项工作的目的是将这些特征结合到满足神经系统中慢性植入所有要求的复合材料中。在第一阶段，使用两种方法证明了将硅酮和荧光聚合物组合的可行性：（1）将硅胶作为碱层和氟聚合物作为表面层的双层层，以及（2）氟化的硅胶共聚物。生产涂层，测试了机械耐用性，稳定性和电阻性，并与parylene-c进行了比较，这是一种商业上可用的蒸气沉积涂层。尽管两种方法在绝缘耐药性方面都与Parylene-C相当，但双层对广泛的底物和优质浸泡稳定性显示出更好的粘附。基于这些结果，其他ICVD硅胶涂层（在浸泡下2岁以上而没有任何电阻损失）中表现出的出色的长期稳定性，选择了双层结构以在II期中进一步发展。在II阶段，将扩大双层结构中使用的组合物范围。生产有机硅涂层的过程将进行缩放，以允许覆盖多种复杂的三维设备。更严格的长期测试将使用现实世界的设备组件作为基材进行，并且将将GVD涂料的性能与最新的商业涂料进行比较。除了机械和电性能测试外，还将系统检查与神经细胞和组织的兼容性，并进行动物植入研究。第二阶段的研究还将解决如何在生物学上修饰这些新涂层以减轻脑组织外型反应。这项工作的最终目标是实现三维神经探针阵列和神经假体组件的单步封装。在此II期下的稳定，耐用，生物相容性的绝缘涂层的开发将实现该目标。这一第二阶段的成功将使GVD能够为研究人员和制造商提供一种经过验证的有效工具，用于神经假体设备的绝缘和封装。在这项工作下开发的涂层将在设备的设计，所使用的材料的选择以及在神经假体设备中可以实现的最小尺寸提供更大的灵活性。从治疗上讲，涂层植入时的性能更好，并在慢性应用中提供安全有效的保护。长期的影响是脱落装置的开发，并加速其作为神经系统疾病的疗法的增殖。