Cellular response to plasma-generated electrical and chemical stimulation of equal electricity

Plasma medicine is a novel field of research that has the potential in life sciences, including cancer treatment. It has been believed that all of these potential applications depend on the chemical factor of the plasma. However, the electrical factors that are produced simultaneously with the chemical factors have not been researched thoroughly. To assess the effect of plasma on the response of cells, a system that enables simultaneous comparison of the effects of chemical and electrical factors of plasma with equal electricity was invented. This system separates the polarity of plasma and isolates the chemical species from the electric stimulation. Using this system, HT-1080 cells were exposed to plasma for 10 min, 1 h, and 24 h. The 10 min plasma treatment showed a clear difference in the polarity of plasma, where cells under exposure to positive plasma died while cells in other conditions survived. An hour of plasma treatment affected the cells under the negative plasma, where the cell viability was reduced to half. Meanwhile, the electric stimulation did not affect the cell viability but did alter the cell membrane. Collectively, this study demonstrates the differential effects of three factors (electric factor, positive plasma, negative plasma) under the same condition: both the electrical and chemical effects of plasma-generated stimuli with equal amounts of electricity were successfully observed.