Li Linze, Jiang Changqing, Duan Wanru, Wang Zhiyan, Zhang Feng, He Changgeng, Long Tiangang, Li Luming
National Engineering Research Center of Neuromodulation, School of Aerospace Engineering, Tsinghua University, Beijing, 100084 China.
School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou, 350108 China.
Microsyst Nanoeng. 2022 Sep 2;8:96. doi: 10.1038/s41378-022-00433-8. eCollection 2022.
Neural electrode interfaces are essential to the stimulation safety and recording quality of various bioelectronic therapies. The recently proposed hierarchical platinum-iridium (Pt-Ir) electrodes produced by femtosecond lasers have exhibited superior electrochemical performance in vitro, but their in vivo performance is still unclear. In this study, we explored the electrochemical performance, biological response, and tissue adhesion of hierarchical Pt-Ir electrodes by implantation in adult rat brains for 1, 8, and 16 weeks. Regular smooth Pt-Ir electrodes were used as a control. The results showed that the electrochemical performance of both electrodes decreased and leveled off during implantation. However, after 16 weeks, the charge storage capacity of hierarchical electrodes stabilized at ~16.8 mC/cm, which was 15 times that of the smooth control electrodes (1.1 mC/cm). Moreover, the highly structured electrodes had lower impedance amplitude and cutoff frequency values. The similar histological response to smooth electrodes indicated good biocompatibility of the hierarchically structured Pt-Ir electrodes. Given their superior in vivo performance, the femtosecond laser-treated Pt-Ir electrode showed great potential for neuromodulation applications.
神经电极界面对于各种生物电子疗法的刺激安全性和记录质量至关重要。最近提出的由飞秒激光制备的分级铂铱（Pt-Ir）电极在体外已表现出优异的电化学性能，但其体内性能仍不清楚。在本研究中，我们通过将分级Pt-Ir电极植入成年大鼠大脑1、8和16周，探索了其电化学性能、生物学反应和组织粘附情况。使用常规光滑Pt-Ir电极作为对照。结果表明，两种电极的电化学性能在植入过程中均下降并趋于稳定。然而，16周后，分级电极的电荷存储容量稳定在约16.8 mC/cm，是光滑对照电极（1.1 mC/cm）的15倍。此外，高度结构化的电极具有较低的阻抗幅度和截止频率值。与光滑电极相似的组织学反应表明分级结构的Pt-Ir电极具有良好的生物相容性。鉴于其优异的体内性能，飞秒激光处理的Pt-Ir电极在神经调节应用中显示出巨大潜力。
