Perspectives and Advances of Nonthermal Plasma Technology in Cancers

Cancer is a devastating and life-threatening disease. It is the second leading cause of death worldwide after heart diseases. While science has significantly advanced to improve the treatment outcome and quality of life in cancer patients, there are still many issues with the current therapies, such as toxicity and the development of resistance to treatment. Among the novel tools to overcome these limitations is nonthermal plasma (NTP) and its treatment regimens. Recent progress in NTP devices with ion temperatures close to room temperature demonstrated significant potential in cancer therapy. NTP devices provide a unique combination of reactive oxygen species (ROS), reactive nitrogen species (RNS), photons, and electric fields that exhibit desirable properties of triggering cell death pathways, selectively for cancer cells. While in principle NTP is nonnecrotic and gentle to the tissue, but reactive oxygen and nitrogen species (RONS)-triggered tumor cell death exhibited to have pro-immunogenic properties. Many in vitro and in vivo experiments have demonstrated antitumor effects of direct NTP, synergistic applications of NTP with anticancer drugs/treatments, and plasma-conditioned medium (PCM) applications against a variety of cancer cells. The latest results and findings in this field are the subject of this review along with a brief lay-reader-explanation of cancer and immunology. In this review, initially, we give an overview of the literature that deals with studies on the use of NTP for cancer treatment. Subsequently, we present typical results from that literature to illustrate the advances of NTP in oncology. Finally, we discuss some challenges and future scopes offered by NTP for cancer treatment.