Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA.
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, USA.
Sci Rep. 2022 May 19;12(1):8386. doi: 10.1038/s41598-022-12303-4.
Magnetoelectric materials hold untapped potential to revolutionize biomedical technologies. Sensing of biophysical processes in the brain is a particularly attractive application, with the prospect of using magnetoelectric nanoparticles (MENPs) as injectable agents for rapid brain-wide modulation and recording. Recent studies have demonstrated wireless brain stimulation in vivo using MENPs synthesized from cobalt ferrite (CFO) cores coated with piezoelectric barium titanate (BTO) shells. CFO-BTO core-shell MENPs have a relatively high magnetoelectric coefficient and have been proposed for direct magnetic particle imaging (MPI) of brain electrophysiology. However, the feasibility of acquiring such readouts has not been demonstrated or methodically quantified. Here we present the results of implementing a strain-based finite element magnetoelectric model of CFO-BTO core-shell MENPs and apply the model to quantify magnetization in response to neural electric fields. We use the model to determine optimal MENPs-mediated electrophysiological readouts both at the single neuron level and for MENPs diffusing in bulk neural tissue for in vivo scenarios. Our results lay the groundwork for MENP recording of electrophysiological signals and provide a broad analytical infrastructure to validate MENPs for biomedical applications.
磁电材料具有变革生物医学技术的巨大潜力。在大脑中感应生物物理过程是一个特别有吸引力的应用，有望使用磁电纳米粒子 (MENP) 作为可注射剂，实现快速的全脑调制和记录。最近的研究已经证明，使用由钴铁氧体 (CFO) 核和压电钛酸钡 (BTO) 壳组成的 MENP 进行体内无线脑刺激。CFO-BTO 核壳 MENP 具有相对较高的磁电系数，已被提议用于大脑电生理学的直接磁粒子成像 (MPI)。然而，获取此类读数的可行性尚未得到证明或系统地量化。在这里，我们提出了实施 CFO-BTO 核壳 MENP 基于应变的有限元磁电模型的结果，并应用该模型来量化对神经电场的磁化响应。我们使用该模型来确定单个神经元水平和体内情况下在大块神经组织中扩散的 MENP 的最佳 MENP 介导的电生理读数。我们的结果为 MENP 记录电生理信号奠定了基础，并为 MENP 在生物医学应用中的验证提供了广泛的分析基础。
