Enhancement of cancer chemotherapy in vitro by intense ultrawideband electric field pulses

Experiments have been performed to enhance the Jurkat cell-killing effects of the cancer chemotherapy agent bleomycin using electric field pulses of 50-200 kV/cm peak electric field strength, similar to 150 ns duration, and nanosecond rise time. Dramatic increases in cell killing (factors of similar to 1000) were observed with a low dose of bleomycin after treatment with trains of ten or more pulses at all electric field strengths tested, compared to pulse-only or drug-only treatments. Cell death occurred within 24 h for treated cells, with some evidence of membrane phosphatidylserine externalization at 6 h postexposure but no significant increase in caspase activity, indicating that the primary mode of cell death was not caspase-mediated apoptosis. (C) 2006 American Institute of Physics.