Electroporation memory and cumulative transport in yeast cells: Refining the asymptotic model for multi-pulse protocols.
TL;DR
A continuous pore formation model adapted for the 8-pulse ESOPE protocol is proposed that provides a quantitative framework for optimising electrochemotherapy parameters in small-cell systems by accounting for cumulative transport and cellular scale variability.
Abstract
Electroporation (EP) alters cell membrane structure and tissue electrical properties by short and intense pulsed electric fields (PEF). This study addresses the discrepancy between theoretical single-pulse electroporation models and experimental cytotoxicity in yeast cells. EP pore models often fail to predict lethal bleomycin uptake in small cells due to rapid pore resealing. We propose a continuous pore formation model adapted for the 8-pulse ESOPE protocol (100µs, 1Hz). By adjusting the equilibrium pore density parameter (NEQ), the model reproduces "electroporation memory", where persistent pores from preceding pulses facilitate cumulative molecular transport during inter-pulse intervals. Simulations demonstrate that reaching the minimum cytotoxic threshold of 100 molecules depends on electric field amplitude and cell size heterogeneity. At 300kV/m, larger cells (radii of 4-5µm) attain lethal concentrations, while smaller cells radii of 3µm) remain viable. This radius-dependent sensitivity explains the heterogeneous population responses observed experimentally. The findings indicate that multi-pulse protocols ensure efficacy by stabilising pore populations and enabling sustained diffusion. This model provides a quantitative framework for optimising electrochemotherapy parameters in small-cell systems by accounting for cumulative transport and cellular scale variability.