Pulsed Electric Field-Induced Ablation of Atherosclerotic Plaque-Forming Cells: A Preliminary In Vitro Investigation

Background: Pulsed electric field (PEF) has been investigated as a local ablation modality in various biomedical applications. Atherosclerotic plaques are composed of pathological cells, including macrophages, vascular smooth muscle cells (SMCs) and foam cells. The in vitro ablation effects of PEF on these plaque-forming cells remain incompletely characterized. Methods: Mouse RAW 264.7 macrophages, MOVAS SMCs, and foam cells derived from both lines were treated with PEF (250–1000 V/cm). Cell death was assessed by live–dead staining. Surface ultrastructural changes were examined by scanning electron microscopy (SEM). Membrane phosphatidylserine externalization was evaluated by Annexin V-FITC/propidium iodide (PI) staining. Expression changes in apoptosis-associated proteins (Bax, Bcl-2, Caspase-3, Cytochrome C) were measured by Western blot. Secretion of selected cytokines (IL-1β, TNF-α, IFN-γ, IL-10, TGF-β) was measured by enzyme-linked immunosorbent assay (ELISA) at 24 h. Results: PEF induced dose-dependent reductions in viability in all tested cell types. SEM revealed pronounced membrane ultrastructural changes, including disruption of the surface meshwork and pore-like features. The proportion of Annexin V-positive cells increased after PEF treatment. The expression levels of apoptosis-associated proteins and their statistical significance varied by cell type and time point. No statistically significant differences were detected in the selected cytokines at 24 h under the tested conditions. Conclusion: Under the tested in vitro conditions, PEF induced dose-dependent ablation effects on atherosclerotic plaque-forming cells, accompanied by membrane ultrastructural alterations and increased Annexin V-positive cell proportions. These findings provide preliminary in vitro evidence warranting further investigation in more physiologically relevant models.