Implantable Biodegradable RF-Powered Tissue Stimulator and Electrodes

描述（由申请人提供）：用于医疗应用的植入式生物可降解电子器械具有在有限时间内（数周至数月）提供治疗或监测功能的潜力，随着应用的预期需求而降解，因此不需要手术取出。然而，仍有许多技术有待开发，以实现实用的生物可降解电子系统。该R21的目标是开发完全可生物降解的射频（RF）功率发生器和刺激电极，作为实现各种外科植入式可生物降解电子设备的新型平台技术。发生器和电极将根据电气规范和形式进行设计，这些规范和形式与可生物降解脊柱融合刺激器（作为该技术的典型应用）兼容。我们的新方法将使用基于生物相容性和生物可吸收镁合金导电和电阻组件的RF线圈电路，并使用相同的合金作为电极材料。我们将使用临床使用的现有不可降解脊柱融合刺激器的电气规范作为指南，设计、制造和测试射频线圈电路和刺激电极，以提供恒定电流刺激。将在体外评估对刺激电极的干细胞增殖和分化反应，并与对常规不可降解电极的反应进行比较。将在栓系硬连线皮下大鼠模型中对评估电极降解和组织相容性的初步实验进行体内评估。将在体外模拟体液中评估射频线圈电路的功能和耦合效率。通过确认预测的细胞反应和组件功能随时间的推移所证明的这些目标的成功完成，将为解决组件优化和完整系统开发的后续研究奠定基础，包括与有源电子器件的集成以及在动物脊柱融合模型中的测试。

DESCRIPTION (provided by applicant): Implantable biodegradable electronic devices for medical applications offer the potential to provide therapeutic or monitoring functions for limited periods of time - weeks to months - degrading in register with the anticipated needs of the application and thus not requiring surgical removal. However, numerous technologies remain to be developed to enable practical biodegradable electronic systems. The goal of this R21 is to develop completely biodegradable radio frequency (RF) power generators and stimulating electrodes as novel platform technology for enabling a variety of surgically implantable biodegradable electronic devices. The generators and electrodes will be designed according to electrical specifications and forms that are compatible with their incorporation into a biodegradable spinal fusion stimulator as a paradigm application of this technology. Our novel approach will be to use RF coil circuits based on biocompatible and bioresorbable magnesium alloy conductive and resistive components, and also use this same alloy as the material for the electrodes. Using the electrical specifications of existing, non-degradable spinal fusion stimulators in clinical use for guidelines, we will design, fabricate, and test RF coil circuits and stimulating electrodes to deliver constant current stimulation. Stem cell proliferative and differentiative responses to the stimulating electrodes will be assessed in vitro and compared with responses to conventional non-degradable electrodes. Pilot experiments to assess electrode degradation and tissue compatibility will be assessed in vivo in a tethered hard-wired subcutaneous rat model. Functionality and coupling efficiency of the RF coil circuit will be assessed in vitro in simulated body fluid. Successful completion of these aims, as demonstrated by confirming predicted cellular responses and component functionalities over time, will establish the basis for follow-on research addressing component optimizations and complete system development, including integration with active electronics, and testing in an animal spinal fusion model.