Numerical Analysis of Bubble Interference on Transmembrane Potential and Electroporation Uniformity in Pulsed Electric Field Systems

INTRODUCTION: Bubble formation resulting from electrolysis under Pulsed Electric Fields (PEF) constitute an important subject of study, since they divert the current and amplify the local electric field via the edge effect. This distortion reduces the efficacy of treatments like pasteurization and tumor ablation, giving rise to regions of high current density, which is the core cause of electrolysis in biological systems. Studying this dynamic allows for the improvement of electrode geometries, influencing the effectiveness and safety of industrial and biomedical protocols.

METHODS: In this work, COMSOL Multiphysics® software was utilized using Finite Elements Method (FEM) to numerically simulate the temporal and spatial variations in the distribution of the transmembrane potential (TMP) and in the number of pores in a biological cell immersed in a liquid medium. An analysis comparing scenarios with and without the presence of gas bubbles provided results in terms of the transmembrane potential and pore density in the plasma membrane (PM), using the TMP as an indicator of the threshold for reversible or irreversible electroporation.

RESULTS: The results demonstrated the bubble presence diverts the current lines, giving rise to a non-uniform distribution of the electric field surrounding the cell. The transmembrane potential was attenuated in the regions shadowed by the bubble and strongly amplified in the adjacent borders, which directly modified the rate of pore formation in the plasma membrane.

CONCLUSION: We conclude that the presence of bubbles compromises the expected uniformity of the electric field in electroporation processes, reducing the effectiveness of the PEF technology and leading to treatment flaws and hazardous electric discharges.