A surface dielectric barrier discharge non-thermal plasma to induce cell death in colorectal cancer cells

Abstract

A novel coaxial surface dielectric barrier discharge (SDBD) non-thermal atmospheric pressure plasma device, driven by a 35.7-kHz DC pulse and adjustable by a pulse-width modulation, was developed in this study and preliminarily tested for its killing effects of a cancer cell type. This study was divided into three phases, namely, air phase, liquid phase, and cell phase. First, the electrical characteristics and emissions were examined. Two-beam UV-LED absorption spectroscopy was also newly developed to measure the absolute hydroxyl radical (OH⋅) density in the filamentary discharge. Then, the effects of energy doses and treatment durations on three types of liquids and on the colorectal adenocarcinoma cell, SW620, were examined. From Lissajous figures (Q–V plot), the developed SDBD possesses the maximum power density and energy dose of 0.33 ± 0.05 W/cm2 and 19.5 ± 3.00 J/cm2, respectively, when the voltage was set at 3.44 kV and the power at 115 mW. From two-beam UV-LED absorption spectroscopy results, the OH⋅ density increased by 0.32, 0.58, and 0.86 × 1019 m−3, with operational powers of 29, 58, and 115 mW, respectively, within 1-min treatment. In liquid phases, the plasma device can increase the concentrations of H2O2 and NO2− in a time-dependent manner. Finally, cell-phase studies, including the examination of the cell morphology, cell viability, and gene expression of the SW620 cell, show that the device can time-dependently induce the mortality of the SW620 cell, relevant to the up-regulation of the Bax/Bcl-2 expression ratio. Taken together, this novel SDBD plasma device shows potential as another alternative for cancer treatment, although further modification is required.

Water Surface Plasma Source for Large Area Water Treatment by Using Volume Dielectric Barrier Discharge

“…N 2 ions first-negative system (B 2 + u → X 2 + g ) at 391.4 nm was detected [16]. For the molecular NO β, γ system, emission lines of low intensity were observed in the range of 200-250 nm because NO is rapidly converted to NO 2 by three body reactions with oxygen in an air plasma [5], [18], [22], [23]. The weak peaks were detected for the N 2 first-positive system (B 3 g → A 3 + u ) at 500-700 nm [18], OH (A-X) at 307 nm [24], and O 2 at 777.0 and 843.8 nm [16], [26], [26].…”

A Meaningful Attempt: Applying Dielectric Barrier Discharge Plasma to Induce Polarization of Macrophages

“…The frequency of DBD device is 7.7 kHz, and the power is 5.2 W. The rms values of voltage and current are 1.7 kV and 67 mA, respectively. Referring to Nupangtha's article [Nupangtha et al, 2021], the power of DBD device was calculated according to Lissajous figure ( Q – V plots, Fig. 1h).…”

“…Because of their high reactivity and short life, the content of ROS/RNS is difficult to be accurately detected. According to Nupangtha's research, when studying the biological effects of plasma, H 2 O 2 and NO 2 − can be used to roughly estimate the content of ROS/RNS [Nupangtha et al, 2021]. DBD plasma have been widely applied to research and treat skin diseases, nonhealing wounds, cancers, and oral infections [Kim et al, 2010; Cheng et al, 2017; Reuter et al, 2018; Duarte and Panariello, 2020].…”

Identification of Reactive Species Produced by Surfaces Dielectric Barrier Discharge Nonthermal Plasma with Gas Sources Variation (Air, N2, O2) to Kill Bacteria

“…Dielectric barrier discharge (DBD) and plasma jet are two methods that are often used to produce nonthermal plasma. From the generated plasma, various types of reactive oxygen species and nitrogen reactive species (ROS and RNS) are formed, including hydroxyl radicals (OH), hydrogen peroxide (H2O2), ozone (O3), atomic oxygen (O), superoxide anions (O2 -), nitric oxide (NO), and peroxynitrite anion (ONOO -), which are considered plasma components that have a role in inactivating microorganisms (Lotfy, 2020;Xu et al, 2015) (Nupangtha et al, 2021).…”

“…Therefore, this study aimed to identify the most effective reactive species between ROS and RNS in inactivating bacteria using three different gas sources, namely free air, oxygen, and nitrogen by using surface dielectric barrier discharge (SDBD) non-thermal plasma. SDBD is a new technique for producing plasma (Nupangtha et al, 2021). Some of the advantages of SDBD are that it uses small power, reduces the burning of cells, and covers a wide sterilization area.…”