Characteristics of plasma in culture medium generated by positive pulse voltage and effects of organic compounds on its characteristics

Abstract

We describe a positive pulse voltage method for generating plasma in culture medium with a composition similar to biological fluids. We also describe the plasma's characteristics, liquid quality, and the effect of organic compounds in the culture medium on the plasma characteristics through comparisons to a solution containing inorganic salts at the same concentrations as in the culture medium. Light emission with Na and OH spectra was observed within a vapor bubble produced by Joule heating at the tip of the electrode. A downward thermal flow and shock wave were caused by the behavior of the vapor bubble. The culture medium pH gradually increased from 7.9 to 8.3 over the discharge time of 300 s. H 2 O 2 was generated 1.1 mg l −1 in the culture medium after discharge for 300 s, and this value was 0.5 mg l −1 lower than the inorganic salts solution which does not contain organic compounds. This study provides important data that will help facilitate more widespread application of plasma medicine.

Analysis of Hydroxyl Radical and Hydrogen Peroxide Generated in Helium-Based Atmospheric-Pressure Plasma Jet and in Different Solutions Treated by Plasma for Bioapplications

“…The ions and organic compounds reacted with H 2 O 2 and consumed the H 2 O 2 in the solutions. 21,37 On the basis of the •OH and H 2 O 2 reaction equation in Eq. 2 and the measured H 2 O 2 concentrations, the authors suggest that the •OH concentration in DMEM should be lower than that in DI water and PBS.…”

“…However, previous study only measured the ROS above plasmatreating solution of one or two kind solution. 12,13 Most study measured the H 2 O 2 and •OH concentration only in single solutions, such as DI water, 12,14,15 PBS, 16 RPMI, [17][18][19] DMEM [20][21][22] or inorganic salt solution. 21 Some study reported ROS measurement in three different solutions [23][24][25] and a study reported 4 different solutions, 26 but have not discussed the ROS generation above solution at the same time.…”

“…12,13 Most study measured the H 2 O 2 and •OH concentration only in single solutions, such as DI water, 12,14,15 PBS, 16 RPMI, [17][18][19] DMEM [20][21][22] or inorganic salt solution. 21 Some study reported ROS measurement in three different solutions [23][24][25] and a study reported 4 different solutions, 26 but have not discussed the ROS generation above solution at the same time. In short, the effects of using different solution on ROS concentration above surfaces of plasma-treating solution and in solution have not been systematically investigated yet.…”

Quantitative evaluation of reactive oxygen and chlorine species generated by discharge in PBS

“…In fact, a downward flow of conductive liquid was observed in a similar experimental setup. 26) Figure 3(e) shows series of typical voltage waveforms with varying the pulse width T p . The bubble formation duration was approximately constant (∼40 μs) with T p , thus the following discharge duration was controlled by T p .…”

“…One of ways to solve the problem is plasma generation in liquid, 4,[25][26][27] which enables us to make the plasma−liquid interface near cells/tissues. This plasma generation in liquid has been studied with and without working gas supply.…”