The interaction of low temperature plasma with liquids is a relevant topic of study to the field of plasma medicine. This is because cells and tissues are normally surrounded or covered by biological fluids. Therefore, the chemistry induced by the plasma in the aqueous state becomes crucial and usually dictates the biological outcomes. This process became even more important after the discovery that plasma activated media can be useful in killing various cancer cell lines. Here, we report on the measurements of concentrations of hydrogen peroxide, a species known to have strong biological effects, produced by application of plasma to a minimum essential culture medium. The activated medium is then used to treat SCaBER cancer cells. Results indicate that the plasma activated medium can kill the cancer cells in a dose dependent manner, retain its killing effect for several hours, and is as effective as apoptosis inducing drugs. V C 2015 AIP Publishing LLC.

The efficacy of the plasma pencil is studied for its cancer therapeutics effects against the SCaBER cell line. First, the SCaBER cells in media were treated with different exposure times of low temperature plasma (LTP). Secondly, LTP activated media was generated by treating the media prior to adding it to the cells. Cell viability was assayed at 0, 24, 48, and 72 h after treatments. The results indicate that both treatments alter cell morphology, cell reattachment, and kill SCaBER cells in an exposure time dependent and delayed manner. Caspase‐3 assays reveal that plasma can activate the cells' apoptotic pathways.

Plasma‐activated media (PAM) can be as effective as direct plasma treatment in killing cancer cells. PAM is produced by exposing liquid cell culture media to low temperature plasma. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the aqueous state play key role in the anti‐tumor effects of PAM. The effectiveness of PAM is highly dependent upon the dose of reactive species. The concentrations of reactive species and consequently the effectiveness of PAM decreases over time after plasma exposure. In this paper, the effect of PAM on the viability of SCaBER cells, originally obtained from a bladder squamous cell carcinoma, is shown and its efficiency at different aging times is evaluated. To investigate the selective effect of plasma on normal epithelial cells, MDCK (Madin‐Darby Canine Kidney) cells from normal epithelial tissue of a dog kidney were treated by PAM. The concentrations of hydrogen peroxide at different times after plasma exposure were measured. Our findings indicate that there is a correlation between PAM efficiency and H2O2 concentration, as both decrease over time.

No abstract

The application of low temperature plasmas in biology and medicine may lead to a paradigm shift in the way various diseases can be treated without serious side effects. Low temperature plasmas generated in gas mixtures that contain oxygen or air produce several chemically reactive species that have important biological implications when they interact with eukaryotic or prokaryotic cells. Here, a review of the effects of low temperature plasma generated by the plasma pencil on different cancerous cells is presented. Results indicate that plasma consistently shows a delayed killing effect that is dose dependent. In addition, there is some evidence that apoptosis is one of the pathways that leads to the death of the cells, indicating that plasma initiates cell signaling pathways.