Rodriguez Osuna Isaac Aaron, Cobelli Pablo, Olaiz Nahuel
Laboratorio de Sistemas Complejos, Departamento de Computación, Instituto de Física del Plasma, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina.
Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina.
Micromachines (Basel). 2022 Jul 31;13(8):1234. doi: 10.3390/mi13081234.
Currently, increasing amounts of pulsed electric fields (PEF) are employed to improve a person's life quality. This technology is based on the application of the shortest high voltage electrical pulse, which generates an increment over the cell membrane permeability. When applying these pulses, an unwanted effect is electrolysis, which could alter the treatment. This work focused on the study of the local variations of the electric field and current density around the bubbles formed by the electrolysis of water by PEF technology and how these variations alter the electroporation protocol. The assays, in the present work, were carried out at 2 KV/cm, 1.2 KV/cm and 0.6 KV/cm in water, adjusting the conductivity with NaCl at 2365 μs/cm with a single pulse of 800 μs. The measurements of the bubble diameter variations due to electrolysis as a function of time allowed us to develop an experimental model of the behavior of the bubble diameter vs. time, which was used for simulation purposes. In the in silico model, we calculated that the electric field and observed an increment of current density around the bubble can be up to four times the base value due to the edge effect around it, while the thermal effects were undesirable due to the short duration of the pulses (variations of ±0.1 °C are undesirable). This research revealed that the rise of electric current is not just because of the shift in electrical conductivity due to chemical and thermal effects, but also varies with the bubble coverage over the electrode surface and variations in the local electric field by edge effect. All these variations can conduce to unwanted limitations over PEF treatment. In the future, we recommend tests on the variation of local current conductivity and electric fields.
目前，越来越多的脉冲电场（PEF）被用于提高人们的生活质量。这项技术基于最短高压电脉冲的应用，该脉冲会使细胞膜通透性增加。施加这些脉冲时，一个不良影响是电解，这可能会改变治疗效果。这项工作聚焦于研究PEF技术电解水形成的气泡周围电场和电流密度的局部变化，以及这些变化如何改变电穿孔方案。在本研究中，实验在水中分别以2 kV/cm、1.2 kV/cm和0.6 kV/cm的电场强度进行，用氯化钠将电导率调整为2365 μs/cm，施加一个800 μs的单脉冲。对电解导致的气泡直径随时间变化的测量，使我们能够建立一个气泡直径与时间关系的实验模型，该模型用于模拟目的。在计算机模型中，我们计算得出，由于气泡周围的边缘效应，气泡周围的电场和电流密度增量可达基础值的四倍，而由于脉冲持续时间短（±0.1°C的变化是不可取的），热效应是不利的。这项研究表明，电流的上升不仅是由于化学和热效应导致的电导率变化，还随电极表面气泡覆盖情况以及边缘效应引起的局部电场变化而变化。所有这些变化都可能对PEF治疗造成不必要的限制。未来，我们建议对局部电流电导率和电场的变化进行测试。
