No abstract

The antimicrobial treatment of wounds is still a major problem. Tissue-tolerable electrical plasma (TTP) is a new approach for topical microbial disinfection of the skin surface. The aim of the present study was to investigate the influence of TTP on a carotenoid profile in relation to skin physiology parameters (epidermal barrier function, stratum corneum (SC) hydration, surface temperature and irritation parameters). We were interested in the interaction of TTP and the antioxidative network, as well as the consequences for skin physiology parameters. These parameters are also indicative of TTP safety in vivo. For plasma application, 'Kinpen 09' was used (surface exposure 30-43°C) for 3 s. Beta-carotene and water profiles were assessed by in vivo Raman microspectroscopy (skin composition analyzer 3510). Skin physiology parameters were measured with Tewameter TM 300, Corneometer CM 825, skin thermometer and Chromameter CR 300. All parameters were assessed non-invasively on seven healthy volunteers before and after plasma application in vivo. We could show that TTP application leads to a decrease in beta-carotene especially in the superficial SC. Skin-surface temperature increased by 1.74°C, while the transepidermal water loss (TEWL) increase indicated an impaired barrier function. SC hydration decreased as seen in water profile especially in the superficial layers and capacitance values. A slight increase in skin redness was measurable. The induction of reactive oxygen species is probably the major contributor of TTP efficacy in skin disinfection. Skin physiology parameters were influenced without damaging the skin or skin functions, indicating the safety of TTP under in vivo conditions.

Aiming at the development of strategies to prevent the hand-foot-syndrome, we propose to evaluate the amount of chemotherapeutics in the human skin together with carotenoids the latter serving as marker substances for the dermal antioxidative status. This approach is demonstrated by applying twocolor Raman spectroscopy at 785 and 532 nm excitation for selective detection of chemotherapeutics and carotenoids, respectively. Porcine ear skin has proven to be suited as a model for corresponding spectroscopic basic in-vitro investigations.Raman intensity, arb. units 500 1000 1500Wavenumber, cm -1 human skin 785 nm human skin 532 nmRaman spectra of human skin recorded at 10 μm depth with an excitation at 785 and 532 nm, respectively. The Raman lines marked with an originate from carotenoids