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Background: The knowledge about the location and kinetics of tattoo pigments in human skin after application and during the recovery is restricted due to the limitation of in vivo methods for visualizing pigments. Here, the localization and distribution of tattoo ink pigments in freshly and old tattooed human skin during the regeneration of the epidermis and dermis were investigated in vivo. Methods: Two-photon excited fluorescence lifetime imaging (TPE-FLIM) was used to identify tattoo ink pigments in human skin in vivo down to the reticular dermis. One subject with a freshly applied tattoo and 10 subjects with tattoos applied over 3 years ago were investigated in the epidermal and dermal layers in vivo. One histological slide of tattooed skin was used to localize skin-resident tattoo pigment using light microscopy. Results: The carbon black particles deposited around the incision have still been visible 84 days after tattoo application, showing delayed recovery of the epidermis. The TPE-FLIM parameters of carbon black tattoo ink pigments were found to be different to all skin components except for melanin. Distinction from melanin in the skin was based on higher fluorescence intensity and agglomerate size. Using TPE-FLIM in vivo tattoo pigment was found in 75% of tattoos applied up to 9 years ago in the epidermis within keratinocytes, dendritic cells, and basal cells and in the dermis within the macrophages, mast cells, and fibroblasts. Loading of highly fluorescent carbon black particles enables in vivo imaging of dendritic cells in the epidermis and fibroblasts in the dermis, which cannot be visualized in native conditions. The collagen I structures showed a higher directionality similar to scar tissue resulting in a greater firmness and decreased elasticity of the tattooed skin. Conclusions: Here, we show the kinetics and location of carbon black tattoo ink pigment immediately after application for the first time in vivo in human skin. Carbon black particles are located exclusively intracellularly in the skin of fresh and old tattoos. They are found within macrophages, mast cells, and fibroblasts in the dermis and within keratinocytes, dendritic cells, and basal cells in the continuously renewed epidermis even in 9-year-old tattoos in skin showing no inflammation. [ABSTRACT FROM AUTHOR]

Confocal Raman microspectroscopy is widely used in dermatology and cosmetology for analysis of the concentration of skin components (lipids, natural moisturizing factor molecules, water) and the penetration depth of cosmetic/medical formulations in the human stratum corneum (SC) in vivo. In recent years, it was shown that confocal Raman microspectroscopy can also be used for noninvasive in vivo depth-dependent determination of the physiological parameters of the SC, such as lamellar and lateral organization of intercellular lipids (ICLs), folding properties of keratin, water mobility, and hydrogen bonding states. The results showed that the strongest skin barrier function, which is primarily manifested by the orthorhombic organization of ICLs, is provided at ≈20–40% SC depth, which is related to the maximal bonding state of water with surrounding components in the SC. The secondary and tertiary structures of keratin determine water binding in the SC, which is depth-dependent. This paper shows the technical possibility and advantage of confocal Raman microspectroscopy in noninvasive investigation of the skin and summarizes recent results on in vivo investigation of the human SC. [ABSTRACT FROM AUTHOR]

Background: The chronicity of psoriasis often requires continuous topical treatment. Materials and Methods: Here, the radical protection of a cream containing various herbal oils was evaluated in vivo by electron paramagnetic resonance (EPR) spectroscopy and its skin penetration by Raman microscopy in intact and barrier-disturbed skin. Changes in skin barrier properties were evaluated after 4 weeks of daily topical application using in vivo laser scanning microscopy (LSM) and transepidermal water loss in 26 healthy volunteers. A randomized, controlled, double-blind, three-arm parallel clinical study evaluated the efficacy of the herbal oil cream compared to a 0.05% calcipotriol-containing cream and to a vehicle cream, in 135 patients with mild to moderate plaque psoriasis with the change in Psoriasis Area and Severity Index (PASI) from baseline to week 12 as the primary endpoint. Results: EPR spectroscopy disclosed a significantly higher radical formation in untreated than skin treated with the herbal oil cream (p ≤ 0.05). LSM measurements indicated a protective skin barrier effect in treated compared to untreated skin. In the clinical trial, the topical application of herbal oils showed a significant reduction of the PASI score compared to topical calcipotriol at week 12 (p = 0.016). The mean reduction in PASI was 49% for the herbal oil cream, 38% for calcipotriol, and 55% for the vehicle cream. The percentage of patients, who reached PASI 50 and 75 at any time point, was 55.9% and 29.4% for the herbal oil cream, 47.4% and 15.8% for calcipotriol, and 23 (60.5%) and 13 (34.2%) for the vehicle, respectively (p > 0.05). The vehicle, originally designed as a placebo, contained a main ingredient of the herbal oil cream and therefore showed corresponding results. Conclusion: The herbal oil cream demonstrated effectiveness in the treatment of mild to moderate plaque psoriasis. [ABSTRACT FROM AUTHOR]

The skin barrier function is mostly provided by the stratum corneum (SC), the uppermost layer of the epidermis. To noninvasively analyze the physiological properties of the skin barrier functionin vivo, it is important to determine the SC thickness. Confocal Raman microscopy (CRM) is widely used for this task. In the present in vivo study, a new method based on the determination of the DNA concentration profile using CRM is introduced for determining the SC thickness. The obtained SC thickness values are compared with those obtained using other CRM-based methods determining the water and lipid depth profiles. The obtained results show almost no significant differences in SC thickness for the utilized methods. Therefore, the results indicate that it is possible to calculate the SC thickness by using the DNA profile in the fingerprint region, which is comparable with the SC thickness calculated by the water depth profiles (ANOVA test p = 0.77) and the lipid depth profile (ANOVA test p = 0.74). This provides the possibility to measure the SC thickness by using the DNA profile, in case the water or lipid profile analyses are influenced by a topically applied formulation. The increase in DNA concentration in the superficial SC (0–2 µm) is related to the DNA presence in the microbiome of the skin, which was not present in the SC depth below 4 µm. [ABSTRACT FROM AUTHOR]

Background: Oxidative stress plays an important role in the pathogenesis of various skin diseases. Thus, the antioxidant network of the skin relies on the uptake of exogenous antioxidants to ensure cell protection against radical formation. Green tea is one of the main sources of polyphenolic antioxidant compounds, but only few data are available on its cutaneous antioxidant effects. Methods: The radical scavenging properties of Benifuuki and Yabukita green tea were investigated in the human skin. Thirty-two participants who met the inclusion criteria were randomized to consume 3 cups per day of either Benifuuki tea, Yabukita tea, or water (control group) for 2 weeks. Electron paramagnetic resonance (EPR) spectroscopy was applied to measure the radical scavenging capacity of the skin in vivo before and after the intervention. Results: Both Yabukita and Benifuuki tea led to an increase in the radical scavenging activity of the skin by 28 and 29%, respectively, and the difference was significant when compared to the control group. Benifuuki tea, previously reported to be superior in bioavailability due to a highly absorbable methylated catechin, did not prove to be more effective than the common Yabukita tea. Conclusion: The results show that green tea enhances the radical scavenging capacity of the skin and support the hypothesis that green tea may offer protection against cutaneous oxidative stress. [ABSTRACT FROM AUTHOR]

Background/Aims: Extrinsic and intrinsic skin aging is subject to constant remodeling and degradation processes, primarily in components of the extracellular matrix. While collagen fibers thin out during the aging process, the amorphous elastin fibers accumulate. These are essential formative components of the dermis. So far, these processes have been detected in vertical histological sections of invasive biopsies and recently in noninvasive horizontal scans. Methods: In this pilot study, a modified noninvasive 2-photon microscope was applied to measure the collagen/elastin index of skin in vivo. The obtained images permit an immediate vertical survey and allow a conclusion on the dermal composition at once. The collagen/elastin index was quantified by the second harmonic to autofluorescence aging index of dermis (SAAID) depending on volunteers' age (18-66 years), gender, and body area. Results: The highest SAAID was measured at the volar forearm as compared to the abdominal SAAID, which was significantly lower (p < 0.05). The gluteal region showed the significantly lowest SAAID (p < 0.05). The SAAID in female skin was higher compared to male skin and decreased with increasing age. Conclusion: These effects are to be considered in subsequent studies to be able to specifically detect and evaluate influences. [ABSTRACT FROM AUTHOR]

Background/Aim: The main reason for extrinsic skin aging is the negative action of free radicals. The formation of free radicals in the skin has been associated with ultraviolet (UV) exposure and also to visible (VIS) and near-infrared (NIR) irradiations. The aim of the present study was to evaluate the efficacy of a sunscreen in the whole solar range. Methods: The radical-scavenging activity of a sunscreen in the UV, VIS, and NIR ranges was evaluated using electron paramagnetic resonance spectroscopy. Ex vivo penetration profiles were determined using confocal Raman microscopy on porcine ear skin at different time points after application. Results: Compared to the untreated skin, the sunscreen decreased the skin radical formation in the UV and VIS regions. Additional protection in the VIS and NIR ranges was observed for the sunscreen containing antioxidants (AO). The penetration depth of the cream was less than 11.2 ± 3.0 µm for all time points. Conclusion: A sunscreen containing AO improved the photoprotection in the VIS and NIR ranges. The sunscreen was retained in the stratum corneum. Therefore, these results show the possibility of the development of effective and safer sunscreen products. [ABSTRACT FROM AUTHOR]

Background: The formation of free radicals in human skin by solar ultraviolet radiation is considered to be the main reason for extrinsic skin aging. The antioxidants in human tissue represent an efficient protection system against the destructive action of these reactive free radicals. In this study, the parameters of the skin, epidermal thickness, stratum corneum moisture, elasticity and wrinkle volume, were determined before and after the treatment with antioxidant- or placebo-containing tablets and creams. Methods: The study included 5 groups of 15 volunteers each, who were treated for 2 months with antioxidant-containing or placebo tablets, creams or a combination of antioxidant-containing tablets and cream. The skin parameters were measured at time point 0 and at week 8 utilizing ultrasound for the determination of epidermal thickness, a corneometer for stratum corneum moisture measurements, skin profilometry for quantifying the wrinkle volume and a cutometer for determining the elasticity. Results: The verum cream had a positive influence on epidermal thickness, elasticity and skin moisture, but the verum tablets improved the epidermal thickness only. The combined application of verum tablets and creams led to a significant improvement of all investigated skin parameters, whereas the application of placebo tablets or cream did not influence any parameters. Conclusion: The topical and oral supplementation of antioxidants can be an instrument to improve several skin parameters and potentially counteract or decelerate the process of extrinsic skin aging. © 2016 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The subject of oil penetration into the skin is controversially discussed in the scientific literature. Methods: Confocal Raman microscopy was used for analyzing oil penetration into the skin. The following methods were applied in the study: methods based on tracking specific peaks (method 1), the nonrestricted multiple least square fit (method 2), analyzing the lipid-to-keratin peak ratio using the perpendicular drop-down cutoff procedure (method 3), and the Gaussian function-based deconvolution procedure (method 4). Results: The results obtained using methods 1, 2 and 4 show that the investigated oils do not penetrate deeper than 11 µm into human and porcine skin. Petrolatum has a prominent swelling effect on the stratum corneum (32% in vivo, 28% ex vivo), while the other oils exhibit no significant swelling effect. By using method 3, the penetration profile of oils, and especially of petrolatum, into the skin was interpreted incorrectly for various reasons that are addressed herein below. Conclusion: Predominantly remaining in the uppermost corneocyte layers of the stratum corneum, topically applied oils do not reach the viable cells of the stratum spinosum. To exclude any possible mistakes when using the lipid-keratin Raman peak (2,820-3,030 cm-1), the penetration analysis should be performed using the Gaussian function-based deconvolution procedure. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Pregnancy and postpartum adaptation cause an increased formation of free radicals. This is associated with various perinatological diseases, e.g. necrotising enterocolitis. The human body has developed a protective system in the form of the antioxidative potential. The present study was the first to investigate the kinetics of the cutaneous antioxidative status in pregnant women and newborns using a non-invasive spectroscopic method. Eighteen pregnant women and their babies took part in the study. A light-emitting diode-based compact scanner system was used for quick non-invasive measurements of carotenoid antioxidants in human skin based on reflection spectroscopy. It could be shown that the antioxidative status of the expectant mothers significantly declined during labour (p < 0.001) and on day 1 after delivery (p < 0.01). Compared to the mothers, the newborns exhibited a significantly higher cutaneous carotenoid concentration on both day 1 (p < 0.01) and 5 (p < 0.01) after delivery. These results suggest that the oxidative stress due to postpartum adaptation is counteracted by an enhanced reservoir of carotenoid antioxidants in the subcutaneous fatty tissue. The peripartum cutaneous carotenoid level of mothers declines continuously, whereas term newborns show very high cutaneous antioxidant values. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The antioxidant status of the human skin provides protection against the destructive action of free radicals. Most antioxidants cannot be synthesized by the human organism itself, but have to be ingested with a healthy nutrition rich in fruit and vegetables. The Korean cuisine is known to be one of the healthiest worldwide. This binational study investigated the cutaneous carotenoid concentrations in German subjects, South Korean subjects and immigrant Korean subjects resident in Germany and examined whether dietary- and lifestyle-related differences are reflected in the cutaneous carotenoid concentrations. Methods: Measurements of the carotenoid concentrations of 714 healthy volunteers were performed using a non-invasive spectroscopic measurement system based on reflectance spectroscopy. Results: In the present study South Korean residents showed a significantly higher antioxidant status than both native German residents and Korean immigrants living in Germany (p < 0.001). The first generation of Korean immigrants to Germany over the age of 50 mostly preserved Korean dietary habits, showing significantly higher concentrations (p < 0.001) than the German-born second and third Korean generations under the age of 50. Conclusion: The results of the study indicate that a healthy nutrition alone does not provide a high antioxidant status unless the stress exposure can be reduced simultaneously. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Pegylated liposomal doxorubicin (PLD) is a highly efficient chemotherapeutic; however, it induces dermal side effects such as palmar-plantar erythrodysesthesia (PPE) in up to 80% of cases, probably by being emitted with the sweat onto the skin surface. Aim: The aim of the present study was to examine whether a topically applied ointment containing antioxidants with a high radical protection factor is able to prevent the formation of PPE. Methods: Twenty patients suffering from ovarian carcinoma and treated with PLD were observed. Results: 60% of the patients tolerated the regular application of the cream and developed no PPE. The remaining 40% interrupted the application. Six of them developed PPE and resumed ointment application thereafter. In these cases the PPE disappeared or was strongly reduced. Conclusion: The results of the observation clearly demonstrate that topical application of the ointment is an efficient strategy against the development of PPE during chemotherapy with PLD. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Vitamin C is a potent radical scavenger and a physiological part of the antioxidant system in human skin. The aim of this study was to measure changes in the radical-scavenging activity of human skin in vivo due to supplementation with different doses of vitamin C and at different time points. Therefore, 33 volunteers were supplemented with vitamin C or placebo for 4 weeks. The skin radical-scavenging activity was measured with electron paramagnetic resonance spectroscopy. After 4 weeks, the intake of 100 mg vitamin C/day resulted in a significant increase in the radical-scavenging activity by 22%. Intake of 180 mg/day even resulted in a significant increase of 37%. No changes were found in the placebo group. A part of the study population was additionally measured after 2 weeks: in this group radical scavenging had already reached maximal activity after 2 weeks. In conclusion, orally administered vitamin C increases the radical-scavenging activity of the skin. The effect occurs fast and is enhanced with higher doses of vitamin C. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]