Low-temperature Plasma - a Prospective Microbicidal Tool

Abstract

The effects of low-temperature plasma treatment on microorganisms typically related to skin diseases are studied qualitatively by the inhibition of growth and viability assays to evaluate the potential for classifying as a prospective antiseptic agent. A variety of microorganisms enveloping gram- negative and gram-positive bacteria as well as one genus of yeast and fungus each were exposed to plasma in vitro. In a comparative approach, two power supplies, both of which produce high voltage pulses yet at different temporal characteristics, are applied for the growth study. While operation with both devices led to growth inhibition of all microbes, the results indicate a superior antimicrobial efficacy for high voltage pulse lengths in the nanosecond scale. Fluorescence assays reveal the efficacy of nanosecond-pulse driven plasma in reducing germ viability. Furthermore, the technical background for patents related to low-temperature plasma technology in the field of plasma medicine is discussed.

Inactivation of Microorganisms Using Cold Atmospheric Pressure Plasma with Different Temporal Discharge Characteristics

“…One of them generated pulses in the microsecond range; the second device generates pulses in the nanosecond range. Some results of this study have already been published in ref . Investigations of other authors indicated a higher efficacy of nanosecond plasma sources in terms of the decontamination capacity …”

“…The gram‐negative bacteria as well as the yeast showed damages in the functional and in the morphological structure (see also). This can be explained by lipid peroxidation of the cell membrane caused by strong oxidizers like OH radicals and H 2 O 2 .…”

Effect of direct cold atmospheric plasma (diCAP) on microcirculation of intact skin in a controlled mechanical environment

“…Various effects induced by CAP have been observed. Consistently, a reduction in a wide range of microorganisms was found in vitro and in vivo by groups all over the globe . Further effects include the induction of angiogenesis, stimulation or inhibition of cell proliferation, up‐ and downregulation of genes in skin cells, and virus inactivation …”

“…Consistently, a reduction in a wide range of microorganisms was found in vitro and in vivo by groups all over the globe. [16][17][18][19][20][21][22][23] Further effects include the induction of angiogenesis, 24 stimulation or inhibition of cell proliferation, 25 up-and downregulation of genes in skin cells, 26 and virus inactivation. 27 Recent studies have revealed a significant impact of short-term diCAP application (up to 90 seconds) on the microcirculation of skin.…”

The topical use of non-thermal dielectric barrier discharge (DBD): Nitric oxide related effects on human skin

“…In particular, the NO-loading effects, skin acidification, increase of dermal microcirculation and known antimicrobial effects [34] could have a clinical relevance. However, to prove the efficacy of DBD devices as NO donor systems in therapies, further studies and clinical trials are necessary.…”