Cancellation effect is present in high-frequency reversible and irreversible electroporation

Area of Science:

• Biophysics
• Cell Biology
• Electroporation Technology

Background:

• High-frequency irreversible electroporation (HF-IRE) uses short biphasic pulses for medical treatments.
• A 'cancellation effect,' where the second pulse reduces the impact of the first, may necessitate higher amplitudes for HF-IRE.
• Understanding this cancellation effect is crucial for optimizing HF-IRE protocols.

Purpose of the Study:

• To investigate the cancellation effect of high-frequency biphasic pulses on CHO-K1 cells.
• To determine how buffer conductivity, pulse duration, and inter-phase delay influence the cancellation effect.
• To elucidate the mechanisms underlying the cancellation effect in electroporation.

Main Methods:

• Exposure of CHO-K1 cells to eight bursts of 1-10 µs pulses with varying inter-phase delays (0.5 µs - 10 ms).
• Evaluation of cell membrane permeability and cell survival rates.
• Experiments conducted in electroporation buffers with varying conductivity.

Main Results:

• The cancellation effect was not observed in membrane permeability experiments in low-conductivity buffer.
• A significant cancellation effect was observed in cell survival across all tested electroporation buffers.
• The cancellation effect was less pronounced with longer pulse durations and longer inter-phase delays.
• Assisted discharge, rather than chloride channel hyperpolarization, partially explains the cancellation effect.

Conclusions:

• The cancellation effect in HF-IRE is dependent on experimental conditions like buffer conductivity and pulse parameters.
• Cell survival is more sensitive to the cancellation effect than membrane permeability.
• Findings suggest assisted discharge plays a role, necessitating further research into HF-IRE mechanisms for improved treatment efficacy.