Effects of Low Temperature Plasmas on Cancer Cells

Biologically tolerant plasmas (BTPs) are plasmas with gas temperatures less than 40 °C that are generated near atmospheric pressures and in non‐toxic gases such as air or helium. BTPs have recently garnered great interest as a therapeutic for cancer. Here, we review and discuss conventional cancer treatments, some of the plasma devices that are currently used and the influence of BTPs on cancer cells such as melanomas, carcinomas, and leukemia. The active agents of BTPs have been investigated and reveal the presence of reactive oxygen species (ROS) such as O, O2−, O3, and OH as well as reactive nitrogen species (RNS) such as NO and NO2. ROS and RNS exhibit oxidative properties and trigger signaling pathways in biological cells. In cancer cells, different doses and plasma induce signaling pathways including apoptosis. The medical applications of cold plasmas are of interest to physicists and to medical researchers. Of all the possible applications of plasma in medicine none holds more importance than the destruction of cancer cells. This paper reviews the works of several groups on this medical application of plasma. There has been convincing evidence that plasma can kill various types of cancer cells in vitro. In addition, it appears that cancer cells can be killed by apoptosis.