Street Matthew G, Welle Cristin G, Takmakov Pavel A
Division of Biology, Chemistry, and Materials Science, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, White Oak Federal Research Center, Silver Spring, Maryland 20993, USA.
Departments of Neurosurgery and Bioengineering, Anschutz Medical Center, University of Colorado, Aurora, Colorado 80045, USA.
Rev Sci Instrum. 2018 Sep;89(9):094301. doi: 10.1063/1.5024686.
Novel therapeutic applications for neural implants require miniaturized devices. Miniaturization imposes stricter requirements for reliability of materials. Pilot clinical studies suggest that rapid failure of the miniaturized neural implants in the body presents a major challenge for this type of technology. Traditional evaluations of neural implant performance over clinically relevant durations present time- and resource-intensive experiments in animals. Reactive accelerated aging (RAA) is an test platform that was developed to expedite durability testing of neural implants, as a screening technique designed to simulate the aggressive physiological environment experienced by the implants. This approach employs hydrogen peroxide, which mimics reactive oxygen species, and a high temperature to accelerate chemical reactions that lead to device degradation similar to that found with devices implanted . The original RAA system required daily manual maintenance and was prone to variability in performance. To address these limitations, this work introduces automated reactive accelerated aging (aRAA) with closed-loop monitoring components that make the system simple, robust, and scalable. The core novel technology in the aRAA is electrochemical detection for feedback control of hydrogen peroxide concentration, implemented with simple off-the-shelf components. The aRAA can run multiple parallel experiments for high-throughput device testing and optimization. For this reason, the aRAA provides a simple tool for rapid evaluation of the durability of neural implants, ultimately expediting the development of a new generation of miniaturized devices with a long functional lifespan.
神经植入物的新型治疗应用需要小型化设备。小型化对材料的可靠性提出了更严格的要求。初步临床研究表明，小型化神经植入物在体内的快速失效对这类技术构成了重大挑战。在临床相关时间段内对神经植入物性能进行传统评估，需要在动物身上进行耗时且资源密集的实验。反应性加速老化（RAA）是一个开发用于加快神经植入物耐久性测试的测试平台，作为一种旨在模拟植入物所经历的恶劣生理环境的筛选技术。这种方法使用模仿活性氧的过氧化氢和高温来加速化学反应，这些反应会导致设备降解，类似于植入设备所发现的降解情况。最初的RAA系统需要每日人工维护，且性能容易出现变化。为了解决这些限制，这项工作引入了具有闭环监测组件的自动反应性加速老化（aRAA），使系统简单、稳健且可扩展。aRAA的核心新技术是用于过氧化氢浓度反馈控制的电化学检测，采用简单的现成组件实现。aRAA可以运行多个并行实验，用于高通量设备测试和优化。因此，aRAA为快速评估神经植入物的耐久性提供了一个简单工具，最终加快了具有长功能寿命的新一代小型化设备的开发。
