Inhibition of murine melanoma tumor growth in vitro and in vivo using an argon-based plasma jet

Background

In recent years, cold physical plasma gained significant interest as a new anticancer tool. Cold plasmas are versatile apparatuses in medicine and material processing. Among different cold plasma devices, the argon plasma jet is an effective apparatus and favorite for researches in plasma medicine science.

Methods

We developed an argon plasma jet for cancer treatments. Using optical emission spectroscopy, the newly developed plasma jet produced a substantial amount of hydroxyl radicals and other reactive oxygen and nitrogen species known to show cytotoxic effects at higher concentrations. In this work, we studied the efficacy of the argon-based plasma jet treatment in murine B16 melanoma cells in vitro and in vivo. In vitro, cell viability, apoptotic gene expression, and cell death patterns were assessed at 24 h and compared against non-malignant murine dermal fibroblasts (MDF). In vivo, B16 cells inoculated into the flank of the mice developed melanoma tumors, which were plasma-treated for 5 min on days 1, 5, and 10 or were left untreated.

Results

Melanoma cells were significantly more sensitive to plasma treatment than MDF under the same in vitro conditions (p= 0.00023). The results revealed that the argon-based plasma jet damaged B16 melanoma cells in vitro selectively without a detrimental effect on non-malignant MDF cells. In the animal model, the tumor volume was significantly reduced after three treatments with the plasma jet(p< 0.01).

Conclusions

The argon plasma jet showed therapeutic anti-melanoma efficacy in vitro and in vivo, which may spur new research lines in melanoma therapy.