  Cold atmospheric plasma (CAP) was shown to affect cells not only directly,
but also indirectly by means of plasma pre-treated solution. This study
investigated a new application of CAP generated in deionized (DI) water for the
cancer therapy. In our experiments, the CAP solution was generated in DI water
using helium as carrier gas. We report on the effects of this plasma solution
in breast (MDA-MD-231) and gastric (NCI-N87) cancer cells. The results revealed
that apoptosis efficiency was dependent on the plasma exposure time and on the
levels of reactive oxygen and nitrogen species (ROS and RNS). The plasma
solution that resulted from 30-minute treatment of DI water had the most
significant effect in the rate of apoptosis.
