Unraveling the interactions between cold atmospheric plasma and skin-components with vibrational microspectroscopy

Abstract

Using infrared and Raman microspectroscopy, the authors examined the interaction of cold atmospheric plasma with the skin's built-in protective cushion, the outermost skin layer stratum corneum. Following a spectroscopic analysis, the authors could identify four prominent chemical alterations caused by plasma treatment: (1) oxidation of disulfide bonds in keratin leading to a generation of cysteic acid; (2) formation of organic nitrates as well as (3) of new carbonyl groups like ketones, aldehydes and acids; and (4) reduction of double bonds in the lipid matter lanolin, which resembles human sebum. The authors suggest that these generated acidic and NO-containing functional groups are the source of an antibacterial and regenerative environment at the treatment location of the stratum corneum. Based upon the author's results, the authors propose a mechanistic view of how cold atmospheric plasmas could modulate the skin chemistry to produce positive long-term effects on wound healing: briefly, cold atmospheric plasmas have the potential to transform the skin itself into a therapeutic resource.

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

“…43,44 In this context, it was hypothesized that NO penetration into the skin may be a possible mechanism for plasma-induced changes of microcirculation. 27,45,46 In general, for diCAP treatment durations of 90 seconds, 180 seconds, and 270 seconds, respectively, we observed a more pronounced impact on microcirculatory parameters with increasing treatment time indicated by an absolute increase in significance levels.…”

“…This general trend is well known for CAP generated in air and it is attributed to reactions of plasma‐generated gaseous species (reactive oxygen and nitrogen species—RONS) with omnipresent H 2 O, which lead to the formation of nitrous acid, nitric acid, and hydrogen peroxide . In this context, it was hypothesized that NO penetration into the skin may be a possible mechanism for plasma‐induced changes of microcirculation …”

Trans-Mucosal Efficacy of Non-Thermal Plasma Treatment on Cervical Cancer Tissue and Human Cervix Uteri by a Next Generation Electrosurgical Argon Plasma Device

“…Raman imaging of solid tissue samples enabled the simultaneous generation of morphological and biochemical information after tissue treatment. This is a great advantage compared to previous studies, which aimed to analyze plasma's effects on lipids in the outermost skin layer of keratinized epithelium by Raman microspectroscopy [43]. Further studies demonstrated the ability of Raman spectroscopy to identify plasma-driven changes in lipids and lipid droplets (composed of phospholipids and triglycerides) in bacterial spores, budding-yeast and HeLa cells [44].…”

Improvement of cutaneous microcirculation by cold atmospheric plasma (CAP): Results of a controlled, prospective cohort study

“…However, our findings indicate that other factors produced by CAP, such as nitric oxide (NO) or electric fields and currents, may also play a major role in the effect of CAP on superficial soft tissue. NO is typically produced by the cell's nitric oxide synthase (NOS) as an endogenous gas with various physiological effects, but it is also created in the field of CAP (Kartaschew et al, 2015;García-Alcantara et al, 2013;Heuer et al, 2015). NO acts as a vasodilator.…”