Use of cold-atmospheric plasma in oncology: a concise systematic review

Abstract

Background:Cold-atmospheric plasma (CAP) is an ionized gas produced at an atmospheric pressure. The aim of this systematic review is to map the use of CAP in oncology and the implemented methodologies (cell targets, physical parameters, direct or indirect therapies).Methods:PubMed, the International Clinical Trials Registry Platform and Google Scholar were explored until 31 December 2017 for studies regarding the use of plasma treatment in oncology (in vitro, in vivo, clinical trials).Results:190 original articles were included. Plasma jets are the most-used production systems (72.1%). Helium alone was the most-used gas (35.8%), followed by air (26.3%) and argon (22.1%). Studies were mostly in vitro (94.7%) and concerned direct plasma treatments (84.2%). The most targeted cancer cell lines are human cell lines (87.4%), in particular, in brain cancer (16.3%).Conclusions:This study highlights the multiplicity of means of production and clinical applications of the CAP in oncology. While some devices may be used directly at the bedside, others open the way for the development of new pharmaceutical products that could be generated at an industrial scale. However, its clinical use strongly needs the development of standardized reliable protocols, to determine the more efficient type of plasma for each type of cancer, and its combination with conventional treatments.

Cold Plasma-Treated Ringer’s Saline: A Weapon to Target Osteosarcoma

“…Cold atmospheric plasmas have been highlighted as a potential therapy against many types of cancers. However, most studies up to now were conducted in vitro (95%), mostly in 2D cultures, and only 26% evaluated the effects of plasma-activated liquids on the cells (as opposed to directly treating the cells with plasma) [44]. The direct application of plasma and the homogeneity of the treatment may depend on tumor size and body location, restricting the possibility of treating tumors hard to reach.…”

“…In our experiments, incubation of cell cultures or tumor sections in contact with PAR for only 2 h was enough to induce cytotoxic effects in SaOS-2, MG-63 and U2-OS cells ( Figure 2). The different p53 and pRB status of these human OS cell lines (p53−/pRB− for SaOS-2, p53+/pRB− for U2-OS and p53−/pRB+ for MG-63) [44] indicates that plasma-activated Ringer's cytotoxic action possibly follows a p53 and pRB− independent mechanism of cell death. Cold atmospheric plasmas are reported to act selectively targeting cancer cell lines without affecting their healthy homologues [50,51].…”

Plasma Medicine: A Field of Applied Redox Biology

“…This is true particularly for cancer cells. After several reports on apoptosis induction in cancer cells in vitro (152)(153)(154)(155), animal studies on transcutaneous plasma treatment of subcutaneously induced solid tumors could prove the general concept of plasmasupported tumor treatment (156,157). However, there are several open questions about the mechanisms of plasma attack on cancer cells, a possible selectivity with regard to healthy tissue or on possible secondary effects distant from the region of local plasma treatment.…”

Anticancer Efficacy of Long-Term Stored Plasma-Activated Medium

“…The fourth state of matter, plasma, is a partially ionized gas containing a high density of electrons and various reactive radicals and non-radicals. Recently, to enable the use of plasma in biomedical applications, various types of low-temperature atmospheric-pressure plasmas have been studied [1][2][3][4][5][6]. Dielectric barrier discharge is most often used to generate plasma because of its high electron density and insulation ability [4].…”

“…New approaches to cancer therapy may involve the use of plasma. Biomedical applications of plasma have been demonstrated in a variety of experiments [5][6][7][8][9][10][11]. Recently, studies have revealed the ability of atmospheric-pressure plasma to selectively eliminate cancer cells, indicating the potential of nonthermal atmospheric-pressure plasma as an anticancer agent [1,3,[7][8][9][10].…”