Quantification of propidium iodide delivery with millisecond electric pulses: A model study

TL;DR

This study presents a model for propidium iodide delivery via millisecond electric pulses, confirming electrophoretic transport's role and validating the model against experimental data for predicting electroporation outcomes.

Contribution

The paper introduces a validated model that accurately predicts propidium iodide delivery and membrane permeabilization during electroporation, highlighting electrophoresis's significance for small molecule transport.

Findings

Electrophoretic transport is key for small molecule delivery.

Membrane permeabilization correlates with transmembrane potential bifurcation.

Model accurately reproduces experimental inverse relationship between conductivity and delivery.

Abstract

A model study of propidium iodide delivery with millisecond electric pulses is presented; this work is a companion of the experimental efforts by Sadik et al. [1]. Both membrane permeabilization and delivery are examined with respect to six extra-cellular conductivities. The transmembrane potential of the permeabilized regions exhibits a consistent value, which corresponds to a bifurcation point in the pore-radius-potential relation. Both the pore area density and membrane conductance increase with an increasing extra-cellular conductivity. On the other hand, the inverse correlation between propidium iodide delivery and extra-cellular conductivity as observed in the experiments is quantitatively captured by the model. This agreement confirms that this behavior is primarily mediated by electrophoretic transport during the pulse. The results suggest that electrophoresis is important even for the delivery of small molecules such as propidium iodide. The direct comparison between model prediction and experimental data presented in this work helps validate the former as a robust predictive tool for the study of electroporation.