Transport of charged small molecules after electropermeabilization - drift and diffusion.

Area of Science:

• Cellular Biophysics
• Molecular Transport Mechanisms
• Electroporation Technologies

Background:

• Electroporation applications are diverse, yet mechanisms remain poorly understood, hindering technology optimization.
• Current models assume passive, diffusive transport across cell membranes post-electroporation.
• This study investigates molecular transport after short electric pulses to challenge existing assumptions.

Purpose of the Study:

• To quantitatively analyze post-permeabilization transport of YO-PRO-1, propidium, and calcein.
• To determine factors influencing molecular transport across electropermeabilized cell membranes.
• To highlight the role of post-pulse transmembrane potential in electroporation models.

Main Methods:

• Quantitative analysis of small molecule transport (influx and efflux).
• Utilized three common electroporation research molecules: YO-PRO-1, propidium, and calcein.
• Applied minimally perturbing 6-nanosecond electric pulses to cells.

Main Results:

• Influx of YO-PRO-1 and propidium (cations) exceeded calcein (anion).
• Calcein efflux from cells was comparable to YO-PRO-1 and propidium influx.
• Transport rates correlated with molecular charge polarity, not size.

Conclusions:

• Electroporation models must account for post-pulse transmembrane potential.
• Molecular charge polarity significantly influences transport across permeabilized membranes.
• Neglecting the post-pulse potential limits understanding and optimization of electroporation.