Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, MA, USA.
Department of Radiology, Interventional Radiology Service, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
Ann Biomed Eng. 2024 Jan;52(1):89-102. doi: 10.1007/s10439-023-03211-3. Epub 2023 Apr 28.
High-voltage pulsed electric fields (HV-PEF) delivered with invasive needle electrodes for electroporation applications is known to induce off-target blood-brain barrier (BBB) disruption. In this study, we sought to determine the feasibility of minimally invasive PEF application to produce BBB disruption in rat brain and identify the putative mechanisms mediating the effect. We observed dose-dependent presence of Evans Blue (EB) dye in rat brain when PEF were delivered with a skull mounted electrode used for neurostimulation application. Maximum region of dye uptake was observed while using 1500 V, 100 pulses, 100 µs and 10 Hz. Results of computational models suggested that the region of BBB disruption was occurring at thresholds of 63 V/cm or higher; well below intensity levels for electroporation. In vitro experiments recapitulating this effect with human umbilical vein endothelial cells (HUVEC) demonstrated cellular alterations that underlie BBB manifests at low-voltage high-pulse conditions without affecting cell viability or proliferation. Morphological changes in HUVECs due to PEF were accompanied by disruption of actin cytoskeleton, loss of tight junction protein-ZO-1 and VE-Cadherin at cell junctions and partial translocation into the cytoplasm. Uptake of propidium iodide (PI) in PEF treated conditions is less than 1% and 2.5% of total number of cells in high voltage (HV) and low-voltage (LV) groups, respectively, implying that BBB disruption to be independent of electroporation under these conditions. 3-D microfabricated blood vessel permeability was found to increase significantly following PEF treatment and confirmed with correlative cytoskeletal changes and loss of tight junction proteins. Finally, we show that the rat brain model can be scaled to human brains with a similar effect on BBB disruption characterized by electric field strength (EFS) threshold and using a combination of two bilateral HD electrode configurations.
高压脉冲电场（HV-PEF）通过侵入性针电极传递用于电穿孔应用已知会引起非靶标血脑屏障（BBB）破坏。在这项研究中，我们试图确定微创 PEF 应用在产生大鼠脑 BBB 破坏的可行性，并确定介导该效应的假定机制。当使用用于神经刺激应用的颅骨安装电极传递 PEF 时，我们观察到大鼠脑中 Evans Blue（EB）染料的剂量依赖性存在。当使用 1500 V、100 个脉冲、100 µs 和 10 Hz 时，观察到最大的染料摄取区域。计算模型的结果表明，BBB 破坏区域发生在 63 V/cm 或更高的阈值下；远低于电穿孔的强度水平。用人类脐静脉内皮细胞（HUVEC）进行的体外实验重现了这种效应，证明了在低电压高脉冲条件下，BBB 表现出的细胞改变在不影响细胞活力或增殖的情况下发生。HUVEC 中的形态变化伴随着肌动蛋白细胞骨架的破坏、细胞连接处紧密连接蛋白-ZO-1 和 VE-Cadherin 的丢失以及部分向细胞质移位。在 PEF 处理条件下，PI 的摄取小于 HV 组和 LV 组中总细胞数的 1%和 2.5%，这意味着在这些条件下，BBB 破坏与电穿孔无关。发现 3-D 微制造血管通透性在 PEF 处理后显著增加，并通过相关的细胞骨架变化和紧密连接蛋白的丢失得到证实。最后，我们表明大鼠脑模型可以与人类大脑相匹配，具有相似的 BBB 破坏效果，其特征是电场强度（EFS）阈值，并使用两种双侧 HD 电极配置的组合。
