Effect of Pulse Width and Intensity on Cell Death in Reversible Electroporation of Cancerous Cells

Abstract

Electroporation (EP) is the process of increasing the permeability of a biological cell or tissue by applying a short-term and sufficient external electric field. The utilization of proper pulse settings is required for EP-based treatments to be successful. Our aim in this study is to examine the effect of different electrical pulse widths and strength on EP efficiency. Human osteosarcoma cells (U20S) were used in the study. Eight-square-pulses with a frequency of 1Hz at 10µs, 1ms, 5ms, 10ms, and 20ms widths with low electric fields (20-500V/cm) were applied to U20S cells. 10-15 minutes after the applications, the cells were incubated in 96-well plates with 10 thousand cells in each well for 24 hours. Efficiency of pulses of different intensity and width was evaluated by MTT analysis method. The percent inhibition of U20S cancer cells elevated as the pulse width increased in almost all electric field values. The highest cell inhibition (%) occurred in pulses with an electric field of 500 V/cm and a width of 20ms (inhibition ratio: 76.25%). No inhibition was observed in the cells at 10µs, 1ms, 5ms, 10ms width pulses with 20 V/cm electric field and 10µs, 1ms width pulses with 50V/cm electric field. In conclusion, our findings show that the electric field intensity and pulse width used in electroporation play an important role in U20S cancer cell death. According to our results, it may be more appropriate to use high-voltage short-width pulses or low-voltage long-width pulses in reversible EP studies.