Narendra P. Singh and Henry Lai
Department of Bioengineering
University of Washington
Seattle, WA
USA

The purpose of this study is to investigate whether low-intensity current affects cells in culture. Two types of human cells: white blood cells (lymphocytes) and leukemia cells (molt-4 cells), were studied. A low-intensity time-varying electric current (0.14 milliamp) generated by the Clark Zapper was applied to cell cultures via two platinum electrodes for 2 hrs at 37o C. Cell counts were made at different times after electric current application. Results show that the current had no significant effect on human white blood cells up to 24 hrs after exposure, whereas it significantly inhibited the growth of leukemia cells. At 24 hrs after exposure, concentration of leukemia cells exposed to the electric current was only 58% of that of non-exposed leukemia cells. These data suggest that the electric current can selectively inhibit the growth of leukemia cells and does not significantly affect normal cells. A manuscript describing these results is in preparation for publication. In addition, the same electric current exposure (0.14 milliamp, 2 hrs at 37oC) was applied to E. coli bacteria cultures. No significant effect of the current was observed in E. coli cultures at 24 hrs after exposure.

Further research should investigate whether this selective electric current-induced growth inhibition also occurs in other types of cancer cells. The critical current parameters and mechanism of this effect should also be investigated.