Assessing Cellular DNA Damage from A Helium Plasma Needle

Abstract

The aim of the present study is to determine the deoxyribonucleic acid (DNA) damage by cells exposed to atmospheric pressure non-thermal plasma (APNTP). Mouse leukocytes embedded in agarose were exposed to the plasma at two different distances from a helium plasma needle outlet and during three different exposure periods. Damage was assessed by the single cell gel electrophoresis assay. The results indicate that, at 0.1 cm from the plasma needle, the exposure caused complete DNA fragmentation determined by the presence of so called "clouds". Samples exposed at 0.5 cm from the slide sample surface presented damage proportional to the exposure periods in terms of tail intensity, tail moment and "clouds" frequency. Studies performed with alkaline single cell gel electrophoresis assay to determine DNA breaks and alkali-labile sites, indicates that DNA damage produced by exposure to APNTP was caused mainly by oxidative radicals, rather than by UV light which causes cyclobutane pyrimidine dimers. These results allow us to conclude that plasma needle induced DNA breaks in mice leukocytes proportionally to exposure time.

Toxicity and Genotoxicity in HeLa and E. coli Cells Caused by a Helium Plasma Needle

“…The fact that there is an evident decrease in viability by plasma treatments discards the first hypothesis. Comet assay results (shown below) clearly indicate that, as reported before (Morales et al, 2013), plasma produces DNA fragmentation, most probably due to RONS. The latter proposal is supported by the fact that the activity of the alkaline phosphatase enzyme (which is included in the chromotest procedure to asses protein synthesis and indirectly to give an idea of toxicity) decreases as the dose increases (Figure 3c), being more evident in the case of the OG100 strain in accordance with survival.…”

“…It must be pointed out the fact that the number of comets per field decreases as the exposure time increases, supporting the idea that cells disappeared prior its inclusion in the agarose matrix. In previous experiments Morales et al (2013) included and lysed the cells before plasma treatment, thus naked DNA was exposed. In the present work, cells were treated and then slides were prepared, so the reduction in the number of comets per slide is due most probably to membrane disruption caused by RONS (Stoffels, 2006;Fridman, 2008).…”

Comet Assay Assessment of DNA Damage in Buccal Mucosa Cells Exposed to X-Rays via Panoramic Radiography

“…10 Large numbers of these DNA clouds were detected in most comet studies of buccal samples. 10,14,15 Accordingly, in the present study, these outliers or invalid comets were excluded from the quantitative analysis to avoid overestimating DNA damage.…”

Virucide properties of cold atmospheric plasma for future clinical applications

“…Moreover, a number of in vitro studies demonstrated DNA damage and genotoxicity following CAP treatment of mammalian cells [Kim et al, 2010b;Ptasinska et al, 2010;Kalghatgi and Azizkhan-Clifford, 2011;Garcia-Alcantra et al, 2013b;Morales-Ramirez et al, 2013]. Kluge et al [2016] recently CAP-treated fertilized chicken eggs inner membranes.…”