Interaction of Cold Atmospheric Argon and Helium Plasma Jets with Bio-Target with Grounded Substrate Beneath

Irina Schweigert,Olga Troitskaya,Olga Koval,Dmitry Zakrevsky,Elena Yelak,Pavel Gugin,Ekaterina Golubitskaya

doi:10.3390/app9214528

Abstract

The cold atmospheric pressure plasma jet interaction with the bio-target is studied in the plasma experiment, 2D fluid model simulations, and with MTT and iCELLigence assays of the viability of cancer cells. It is shown, for the first time, that the use of the grounded substrate under the media with cells considerably amplifies the effect of plasma cancer cell treatment in vitro. Plasma devices with cylindrical and plane geometries generating cold atmospheric plasma jets are developed and tested. The sequence of the streamers which forms the plasma jet is initiated with a voltage of 2.5–6.5 kV applied with the frequency 40 kHz. We suggest using the grounded substrate under the bio-target during the plasma jet treatment of cancer cells. The analysis of the measured plasma spectra and comparison of OH-line intensity for different voltages and gas flow rates allows us to find a range of optimal plasma parameters for the enhanced OH generation. The time-dependent viability is measured for human cell lines, A431 (skin carcinoma), HEK 293 (kidney embryonic cells), and A549 (human lung adenocarcinoma cells) after the plasma jet treatment. The results with cell-based experiments (direct treatment) performed with various plasma jet parameters confirm the maximum efficiency of the treatment with the optimal plasma parameters.

Highlights

Plasma devices generating the streamer type of breakdown in a mixture of noble gases and air have been widely used in medicine
In the experiment and 2D fluid model simulations, we study the influence of the presence of the grounded substrate beneath the plate with the media and cells on plasma characteristics and the efficiency of cancer cell treatment
With further increasing U, the glow propagates inside the capillary and at some critical voltage Ucr the plasma jet starts to propagate beyond the dielectric tube over the inert gas flow in surrounding atmosphere

Summary

Introduction

Plasma devices generating the streamer type of breakdown in a mixture of noble gases and air have been widely used in medicine (see, for example [1,2]). The most typical plasma devices operate at 10–50 kHz frequency with the voltage of 2.5 kV–20 kV, applied to the electrode embedded inside of the dielectric tube. The streamer appears over the positive cycle of the applied voltage and propagates inside and outside of the dielectric tube [3,4]. A noble gas is pumping through the dielectric tube since the critical voltage of the breakdown in the noble gases is essentially lower that in the atmospheric air.

Methods

Results

Conclusion