Establishing electroporation thresholds for targeted cell specific cardiac ablation in a 2D culture model

Background: Irreversible electroporation has emerged as a new modality to overcome issues associated with other energy sources for cardiac ablation. Strong evidence on the optimal, effective, and selective voltage threshold is lacking for both in vitro and preclinical in vivo studies. The aim of this study is to examine the optimal threshold for selective cell ablation on cardiac associated cell types.

Methods: Conventional monophasic and biphasic pulses of different field strength were delivered in a monolayer culture system of cardiomyocytes, neurons, and adipocytes. The dynamics of cell death mechanisms were examined at different time points.

Results: Neurons exhibit higher susceptibility to electroporation and cell death at higher field strength of 1250 V/cm in comparison to cardiomyocytes. Cardiac adipocytes showed lower susceptibility to electroporation in comparison to other cell types. A significant proportion of cardiomyocytes recovered after 24 h postelectroporation, while neuronal cell death remained consistent but with a significant delayed cell death at a higher voltage threshold. Caspase 3/7 activity was observed in both cardiomyocytes and neurons, with a higher level of activity in cardiomyocytes in response to electroporation. Biphasic and monophasic pulses showed no significant difference in both cell types, and significantly lower cell death in neurons when inter pulse interval was reduced.

Conclusions: This study presents important findings on the differences in the susceptibility of neurons and cardiomyocytes to irreversible electroporation. Cell type alone yielded selective and different dynamics in terms of the evolution and signaling mechanism of cell death in response to electroporation.