Role of cell density and proximity in electroporation for tissue ablation.

Electroporation has advanced significantly in biomedical applications, particularly in tissue ablation. While the influence of individual cellular features, such as cell size and nucleus-to-cytoplasm ratio, on ablation is recognized, this study highlights the key role of the cell grouping factor, namely cell density. Experiments using 2D cell monolayers demonstrated a density-dependent ablation effect: higher cell density significantly elevates resistance to electroporation, evident from reduced ablation areas and ~30% higher lethal electric thresholds (LETs). To explain this, a cell-cell proximity electroporation model was established representing cell density by intercellular distance and degree of containment. It indicated significant inhibition when cells were closely spaced (0-2 µm), with lower pore density and reduced pore area ratios (PARs). This inhibitory effect decays logarithmically as spacing increases, persisting over several cell diameters. Furthermore, fully surrounded cells exhibit a 33% lower PAR than isolated cells, consistent with the observed LET gap between high- and low-density populations. As such, the shielding effect from neighboring cells leads to the density-dependent electroporation at cellular scale and may therefore account for the density-dependent ablation observed at tissue scale. In light of this, considering tissue-specific cell density are critical for better mimicking in vivo conditions, and improving precision in electroporation-based tissue therapies.