Non-thermal Plasma Needle Research Articles

Non-thermal plasma needle as an effective tool in dimethoate removal from water

Intensive use of pesticides requires innovative approaches for their removal from the environment. Here we report the method for degradation of dimethoate in water using non-thermal plasma needle and analyze kinetics of dimethoate removal and possible degradation pathways. The effects of dimethoate initial concentration, plasma treatment time, Argon flow rate and the presence of radical promoters on the effectiveness of proposed method are evaluated. With argon flow rate of 0.5 slm (standard litres per minute) 1 × 10−4 M dimethoate can be removed within 30 min of treatment. Using UPLC analysis it was confirmed that one of the decomposition products is dimethoate oxo-analogue omethoate, which is in fact more toxic than dimethoate. However, the overall toxicity of contaminated water was reduced upon the treatment. The addition of H2O2 as a free radical promoter enhances dimethoate removal, while K2S2O8 results with selective conversion to omethoate. Using mass spectrometry in combination with the theoretical calculations, possible degradation pathways were proposed. The feasibility of the proposed method for dimethoate degradation in real water samples is confirmed. The proposed method is demonstrated as a highly effective approach for dimethoate removal without significant accumulation of undesirable toxic products and secondary waste.

The study of thermal description for non-thermal plasma needle system

Cold plasma is a relatively low temperature gas, so this feature enables us to use cold plasma to treat thermally sensitive materials including polymers and biologic tissues. In this research, the non-thermal plasma system is designed with diameter (3 mm, 10 mm) Argon at atmospheric pressure as well as to be suitable for use in medical and biotechnological applications.The thermal description of this system was studied and we observed the effect of the diameter of the plasma needle on the plasma, when the plasma needle slot is increased the plasma temperature decrease, as well as the effect of the voltages applied to the temperature of the plasma, where the temperature increasing with increasing the applied voltage . Results showed that the plasma temperature would be low, which enables the use of this system in many medical aspects.

Effects of a non-thermal plasma needle device on HPV-16 positive cervical cancer cell viability in vitro.

Non-thermal atmospheric pressure plasma has been demonstrated to inactivate a wide range of surface-dwelling pathogenic microorganisms including airborne viral particles, vegetative bacteria and bacterial spores. This shows the promise of plasma-based decontamination procedures for broad-spectrum sterilization and disinfection and promotes the in-depth and systematic study of how plasma treatment conditions relate to pathogen inactivation efficiency. A wide knowledge gap nonetheless exists regarding whether certain plasma parameters and exposure conditions can alter the resistance of virus-linked cancer cells to treatment. The current work reveals the effects of a non-thermal needle-shaped atmospheric-pressure plasma on the viability of an adherent human cervical carcinoma cell line containing a human papillomavirus type 16 (HPV-16) provirus. Using a helium plasma device driven by 8 kV, 2 kHz, 150 ns pulses, CaSki cells moistened with culture medium were exposed to plasma for different treatment durations, gap distances and gas flow rates. Open-well exposure to helium flow alone for 120 s did not produce significant changes in CaSki cell viability. By comparison, cells exposed to plasma showed a dose-dependent reduction in viability from at least 15% to 60% compared to the control. These findings reveal possibilities for NTP treatment of HPV-16 infected cervical cancers and indicate the importance of NTP parameters to treatment outcome.

Evaluation of a nonthermal plasma needle to eliminate ex vivo biofilms in root canals of extracted human teeth

To evaluate the efficacy of a nonthermal plasma (NTP) at atmospheric pressure on ex vivo biofilm in root canals of extracted teeth. Intracanal contents from three teeth with root canal infections were collected, pooled and grown in thirty-five microCT-mapped root canals of extracted and instrumented human teeth. One group of teeth was treated with NTP, another with 6% NaOCl and one set was left untreated. The intracanal contents from twenty-seven teeth (nine teeth in each group) were plated on agar and colony forming units were determined. Parametric test of one-way analysis of variance (anova) was used to analyse statistical significance. The remaining teeth were cut open, stained with LIVE/DEAD(®) and examined with confocal laser scanning microscopy. The untreated root canals were covered with biofilm of varying thickness. Treatment with nonthermal plasma decreased the number of viable bacteria in biofilms by one order of magnitude, whilst the NaOCl control achieved a reduction of more than four magnitudes. Both the NTP and the NaOCl treatment results were significantly different from the negative control (P < 0.05). The nonthermal plasma displayed antimicrobial activity against endodontic biofilms in root canals, but was not as effective as the use of 6% NaOCl.

Nonthermal Plasma Needle: Development and Targeting of Melanoma Cells

A nonthermal plasma torch has been developed to study the targeted killing of melanoma cells. In this paper, 1205Lu melanoma cells and keratinocytes were exposed to the plasma. These cells were transfected with green fluorescent protein in order to establish a system for coculture with primary keratinocytes. Results show that a 10 s treatment with plasma causes a morphological change in the melanoma cells, as observed after 18 h. However, after only 15 min following plasma treatment, a significant killing of melanoma cells was observed, with a much reduced killing of keratinocytes. Nonthermal plasma may serve as an effective tool for future therapeutic cancer treatment.