Effect of high voltage pulses on survival of Chinese hamster V79 lung fibroblast cells

The objective is to study the effect of high voltage pulses on living cells to find the most effective combination of physical parameters to be used in tumour therapy. Four parameters that affect the cell survival are the pulse shape, electric field strength, pulse length and the number of pulses and their cell killing effect were investigated in this work. High voltage square wave or exponentially decaying pulses was applied to V79 lung fibroblast cells in suspension with 10(6) cells per mi at room temperature after 5 min of acclimatisation in a vial with electrodes. For eight exponential decaying pulses with a pulse length of 1 ms, 50% reduction in cell survival is achieved around 850 V/cm. For eight square wave pulses generated by the BTX820, the corresponding electric field strength is 820 V/cm. Using square wave pulses generated by the Dialog device, the largest reduction in cell survival was achieved at electric field strength of 2400 V/cm resulting in 60% cell survival. At low electric field strengths of about 600 V/cm, very long pulses of several ms are required to kill the cells. However, at high field strengths of about 1200 V/cm short pulses of 0.1 ms kill 50% of the cells. Treatment performed with different number of pulses at field strength show an effective killing at about 8 pulses. (C) 1998 Elsevier Science S.A. All rights reserved.