Validation of Cyanoacrylate Method for Collection of Stratum Corneum in Human Skin for Lipid Analysis

DEFF Research Database (Denmark)

Jungersted, JM; Hellgren, Lars; Drachmann, Tue

2010-01-01

Background and Objective: Lipids in the stratum corneum (SC) are of major importance for the skin barrier function. Many different methods have been used for the collection of SC for the analysis of SC lipids. The objective of the present study was to validate the cyanoacrylate method for the col......Background and Objective: Lipids in the stratum corneum (SC) are of major importance for the skin barrier function. Many different methods have been used for the collection of SC for the analysis of SC lipids. The objective of the present study was to validate the cyanoacrylate method...

Characterization of skin friction coefficient, and relationship to stratum corneum hydration in a normal Chinese population.

Science.gov (United States)

Zhu, Y H; Song, S P; Luo, W; Elias, P M; Man, M Q

2011-01-01

Studies have demonstrated that some cutaneous biophysical properties vary with age, gender and body sites. However, the characteristics of the skin friction coefficient in different genders and age groups have not yet been well established. In the present study, we assess the skin friction coefficient in a larger Chinese population. A total of 633 subjects (300 males and 333 females) aged 0.15-79 years were enrolled. A Frictiometer FR 770 and Corneometer CM 825 (C&K MPA 5) were used to measure the skin friction coefficient and stratum corneum hydration, respectively, on the dorsal surface of the hand, the forehead and the canthus. In the females, the maximum skin friction coefficients on both the canthus and the dorsal hand skin were observed around the age of 40 years. In the males, the skin friction coefficient on the dorsal hand skin gradually increased from 0 to 40 years of age, and changed little afterward. Skin friction coefficients on some body sites were higher in females than in age-matched males in some age groups. On the canthus and the dorsal hand skin of females, a positive correlation was found between skin friction coefficient and stratum corneum hydration (p skin friction coefficient was positively correlated with stratum corneum hydration on the forehead and the dorsal hand skin (p skin friction coefficient varies with age, gender and body site, and positively correlates with stratum corneum hydration on some body sites. Copyright © 2010 S. Karger AG, Basel.

Penetration route of functional molecules in stratum corneum studied by time-resolved small- and wide-angle x-ray diffraction

International Nuclear Information System (INIS)

Hatta, Ichiro; Ohta, Noboru; Yagi, Naoto; Nakazawa, Hiromitsu; Obata, Yasuko; Inoue, Katsuaki

2011-01-01

We studied effects of functional molecules on corneocytes in stratum corneum using time-resolved small- and wide-angle x-ray diffraction after applying a functional molecule. From these results it was revealed that in the stratum corneum a typical hydrophilic molecule, ethanol, penetrates via the transcellular route and on the other hand a typical hydrophobic molecule, d-limonene, penetrates via the intercellular route.

Review of Stratum Corneum Impedance Measurement in Non-Invasive Penetration Application

Directory of Open Access Journals (Sweden)

Fei Lu

2018-03-01

Full Text Available Due to advances in telemedicine, mobile medical care, wearable health monitoring, and electronic skin, great efforts have been directed to non-invasive monitoring and treatment of disease. These processes generally involve disease detection from interstitial fluid (ISF instead of blood, and transdermal drug delivery. However, the quantitative extraction of ISF and the level of drug absorption are greatly affected by the individual’s skin permeability, which is closely related to the properties of the stratum corneum (SC. Therefore, measurement of SC impedance has been proposed as an appropriate way for assessing individual skin differences. In order to figure out the current status and research direction of human SC impedance detection, investigations regarding skin impedance measurement have been reviewed in this paper. Future directions are concluded after a review of impedance models, electrodes, measurement methods and systems, and their applications in treatment. It is believed that a well-matched skin impedance model and measurement method will be established for clinical and point-of care applications in the near future.

Dehydration of multilamellar fatty acid membranes: Towards a computational model of the stratum corneum

Science.gov (United States)

MacDermaid, Christopher M.; DeVane, Russell H.; Klein, Michael L.; Fiorin, Giacomo

2014-12-01

The level of hydration controls the cohesion between apposed lamellae of saturated free fatty acids found in the lipid matrix of stratum corneum, the outermost layer of mammalian skin. This multilamellar lipid matrix is highly impermeable to water and ions, so that the local hydration shell of its fatty acids may not always be in equilibrium with the acidity and relative humidity, which significantly change over a course of days during skin growth. The homeostasis of the stratum corneum at each moment of its growth likely requires a balance between two factors, which affect in opposite ways the diffusion of hydrophilic species through the stratum corneum: (i) an increase in water order as the lipid lamellae come in closer contact, and (ii) a decrease in water order as the fraction of charged fatty acids is lowered by pH. Herein molecular dynamics simulations are employed to estimate the impact of both effects on water molecules confined between lamellae of fatty acids. Under conditions where membrane undulations are energetically favorable, the charged fatty acids are able to sequester cations around points of contact between lamellae that are fully dehydrated, while essentially maintaining a multilamellar structure for the entire system. This observation suggests that the undulations of the fatty acid lamellae control the diffusion of hydrophilic species through the water phase by altering the positional and rotational order of water molecules in the embedded/occluded "droplets."

Non steady-state descriptions of drug permeation through stratum corneum. I. The biphasic brick-and-mortar model.

Science.gov (United States)

Heisig, M; Lieckfeldt, R; Wittum, G; Mazurkevich, G; Lee, G

1996-03-01

The diffusion equation should be solved for the non-steady-state problem of drug diffusion within a two-dimensional, biphasic stratum corneum membrane having homogeneous lipid and corneocyte phases. A numerical method was developed for a brick-and-mortar SC-geometry, enabling an explicit solution for time-dependent drug concentration within both phases. The lag time and permeability were calculated. It is shown how the barrier property of this model membrane depends on relative phase permeability, corneocyte alignment, and corneocyte-lipid partition coefficient. Additionally, the time-dependent drug concentration profiles within the membrane can be observed during the lag and steady-state phases. The model SC-membrane predicts, from purely morphological principles, lag times and permeabilities that are in good agreement with experimental values. The long lag times and very small permeabilities reported for human SC can only be predicted for a highly-staggered corneocyte geometry and corneocytes that are 1000 times less permeable than the lipid phase. Although the former conclusion is reasonable, the latter is questionable. The elongated, flattened corneocyte shape renders lag time and permeability insensitive to large changes in their alignment within the SC. Corneocyte/lipid partitioning is found to be fundamentally different to SC/donor partitioning, since increasing drug lipophilicity always reduces both lag time and permeability.

Study on the lipid organization of stratum corneum lipid models by (cryo-) electron diffraction

NARCIS (Netherlands)

Pilgram, GSK; Pelt, AMEV; Oostergetel, GT; Koerten, HK; Bouwstra, JA

The barrier function of the skin resides in the stratum corneum (SC), This outermost layer consists of protein-rich corneocytes and lipid-rich intercellular domains. These domains form the rate-limiting step for transepidermal water loss and the penetration of substances from the environment. To

Effect of stratum corneum heterogeneity, anisotropy, asymmetry and follicular pathway on transdermal penetration.

Science.gov (United States)

Barbero, Ana M; Frasch, H Frederick

2017-08-28

The impact of the complex structure of the stratum corneum on transdermal penetration is not yet fully described by existing models. A quantitative and thorough study of skin permeation is essential for chemical exposure assessment and transdermal delivery of drugs. The objective of this study is to analyze the effects of heterogeneity, anisotropy, asymmetry, follicular diffusion, and location of the main barrier of diffusion on percutaneous permeation. In the current study, the solution of the transient diffusion through a two-dimensional-anisotropic brick-and-mortar geometry of the stratum corneum is obtained using the commercial finite element program COMSOL Multiphysics. First, analytical solutions of an equivalent multilayer geometry are used to determine whether the lipids or corneocytes constitute the main permeation barrier. Also these analytical solutions are applied for validations of the finite element solutions. Three illustrative compounds are analyzed in these sections: diethyl phthalate, caffeine and nicotine. Then, asymmetry with depth and follicular diffusion are studied using caffeine as an illustrative compound. The following findings are drawn from this study: the main permeation barrier is located in the lipid layers; the flux and lag time of diffusion through a brick-and-mortar geometry are almost identical to the values corresponding to a multilayer geometry; the flux and lag time are affected when the lipid transbilayer diffusivity or the partition coefficients vary with depth, but are not affected by depth-dependent corneocyte diffusivity; and the follicular contribution has significance for low transbilayer lipid diffusivity, especially when flux between the follicle and the surrounding stratum corneum is involved. This study demonstrates that the diffusion is primarily transcellular and the main barrier is located in the lipid layers. Published by Elsevier B.V.

Synchrotron X-ray scattering study on stratum corneum of skin. Toward applied research based upon basic research

International Nuclear Information System (INIS)

Hatta, Ichiro; Ohta, Noboru; Yagi, Naoto

2008-01-01

On considering the applied research on stratum corneum of skin, it is indispensable to know the structure at the molecular level. However, there is even now in a controversy among the researchers who are performing its X-ray scattering study. Here we introduce our solution for the two problems: One is the correlation between the lamellar structures and hydrocarbon-chain packings in intercellular lipid matrix and the other is the existence of water layers in the short lamellar structure. These studies have become possible for the first time by making good use of synchrotron small-angle/wide-angle X-ray diffraction. Based upon the structural evidence, we can further carry out the applied research in stratum corneum. (author)

Turn-over of Stratijm Corneum in Leprosy

Directory of Open Access Journals (Sweden)

R P Okhandiar

1987-01-01

Full Text Available Stratum corneum showed increased proliferative activity on the patches of leprosy as evidenced by a significantly fast stratum corneum turnover time (p 0.001 measured by fluorescent staining technic with dansyl chloride. These findings suggest imperfect keratinization on the patches of leprosy leading to formation of structurally weak stratum corneum.

A mechanistic insight into the mechanical role of the stratum corneum during stretching and compression of the skin.

Science.gov (United States)

Leyva-Mendivil, Maria F; Page, Anton; Bressloff, Neil W; Limbert, Georges

2015-09-01

The study of skin biophysics has largely been driven by consumer goods, biomedical and cosmetic industries which aim to design products that efficiently interact with the skin and/or modify its biophysical properties for health or cosmetic benefits. The skin is a hierarchical biological structure featuring several layers with their own distinct geometry and mechanical properties. Up to now, no computational models of the skin have simultaneously accounted for these geometrical and material characteristics to study their complex biomechanical interactions under particular macroscopic deformation modes. The goal of this study was, therefore, to develop a robust methodology combining histological sections of human skin, image-processing and finite element techniques to address fundamental questions about skin mechanics and, more particularly, about how macroscopic strains are transmitted and modulated through the epidermis and dermis. The work hypothesis was that, as skin deforms under macroscopic loads, the stratum corneum does not experience significant strains but rather folds/unfolds during skin extension/compression. A sample of fresh human mid-back skin was processed for wax histology. Sections were stained and photographed by optical microscopy. The multiple images were stitched together to produce a larger region of interest and segmented to extract the geometry of the stratum corneum, viable epidermis and dermis. From the segmented structures a 2D finite element mesh of the skin composite model was created and geometrically non-linear plane-strain finite element analyses were conducted to study the sensitivity of the model to variations in mechanical properties. The hybrid experimental-computational methodology has offered valuable insights into the simulated mechanics of the skin, and that of the stratum corneum in particular, by providing qualitative and quantitative information on strain magnitude and distribution. Through a complex non-linear interplay

Lipid composition of the stratum corneum and cutaneous water loss in birds along an aridity gradient

NARCIS (Netherlands)

Champagne, Alex M.; Munoz-Garcia, Agusti; Shtayyeh, Tamer; Tieleman, B. Irene; Hegemann, Arne; Clement, Michelle E.; Williams, Joseph B.

2012-01-01

Intercellular and covalently bound lipids within the stratum corneum (SC), the outermost layer of the epidermis, are the primary barrier to cutaneous water loss (CWL) in birds. We compared CWL and intercellular SC lipid composition in 20 species of birds from desert and mesic environments.

Stratum corneum lipid organization as observed by atomic force, confocal and two-photon excitation fluorescence microscopy

DEFF Research Database (Denmark)

Norlén, Lars; Plasencia Gil, Maria Inés; Bagatolli, Luis

2008-01-01

-related biophysical techniques (e.g. atomic force microscopy and confocal/two-photon excitation fluorescence microscopy), it was recently shown that reconstituted membranes composed of extracted decontaminated human stratum corneum lipids do not form a fluid phase, but exclusively a single-gel phase that segregates...

Mechanics, morphology, and mobility in stratum corneum membranes

Science.gov (United States)

Olmsted, Peter; Das, Chinmay; Noro, Massimo

2012-02-01

The stratum corneum is the outermost layer of skin, and serves as a protective barrier against external agents, and to control moisture. It comprises keratin bodies (corneocytes) embedded in a matrix of lipid bilayers. Unlike the more widely studied phospholipid bilayers, the SC bilayers are typically in a gel-like state. Moreover, the SC membrane composition is radically different from more fluid counterparts: it comprises single tailed fatty acids, ceramides, and cholesterol; with many distinct ceramides possessing different lengths of tails, and always with two tails of different lengths. I will present insight from computer simulations into the morphology, mechanical properties, and diffusion (barrier) properties of these highly heterogeneous membranes. Our results provide some clue as to the design principles for the SC membrane, and is an excellent example of the use of wide polydispersity by natural systems.

Interactions of Inertial Cavitation Bubbles with Stratum Corneum Lipid Bilayers during Low-Frequency Sonophoresis

OpenAIRE

Tezel, Ahmet; Mitragotri, Samir

2003-01-01

Interactions of acoustic cavitation bubbles with biological tissues play an important role in biomedical applications of ultrasound. Acoustic cavitation plays a particularly important role in enhancing transdermal transport of macromolecules, thereby offering a noninvasive mode of drug delivery (sonophoresis). Ultrasound-enhanced transdermal transport is mediated by inertial cavitation, where collapses of cavitation bubbles microscopically disrupt the lipid bilayers of the stratum corneum. In...

Role of ascorbic acid in stratum corneum lipid models exposed to UV irradiation.

Science.gov (United States)

Trommer, Hagen; Böttcher, Roif; Pöppl, Andreas; Hoentsch, Joachim; Wartewig, Siegfried; Neubert, Reinhard H H

2002-07-01

The effects of ascorbic acid on Stratum corneum lipid models following ultraviolet irradiation were studied adding iron ions as transition metal catalysts. Lipid peroxidation was quantified by the thiobarbituric acid assay. The qualitative changes were studied on a molecular level by mass spectrometry. To elucidate the nature of free radical involvement we carried out electron paramagnetic resonance studies. The influence of ascorbic acid on the concentration of hydroxyl radicals was examined using the spin trapping technique. Moreover, we checked the vitamin's ability to react with stable radicals. Ascorbic acid was found to have prooxidative effects in all lipid systems in a concentration dependent manner. The degradation products of ascorbic acid after its prooxidative action were detected. The concentration of the hydroxyl radicals in the Fenton assay was decreased by ascorbic acid. The quantification assay of 2,2-diphenyl-1-picrylhydrazyl hydrate showed reduced concentration levels of the stable radical caused by ascorbic acid. Considering human skin and its constant exposure to UV light and oxygen, an increased pool of iron ions in irradiated skin and the depletion of co-antioxidants, the administration of ascorbic acid in cosmetic formulations or in sunscreens could unfold adverse effects among the Stratum corneum lipids.

Investigation of the cosmetic ingredient distribution in the stratum corneum using NanoSIMS imaging

International Nuclear Information System (INIS)

Tanji, N.; Okamoto, M.; Katayama, Y.; Hosokawa, M.; Takahata, N.; Sano, Y.

2008-01-01

In order to understand the mechanisms of action of cosmetic ingredients, it is important to establish the distribution of the component agents within the epidermis of the skin. To date, time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been used to detect cosmetic ingredients in the skin. However, it is technically difficult to investigate the distribution of the agents in the stratum corneum using TOF-SIMS. Therefore, an analytical method with higher spatial resolution is required. In this study, we investigated an imaging analysis technique based on NanoSIMS to detect cosmetic ingredients in the skin. Pig skin was used as a model for human skin. The sample was treated with a cosmetic formulation containing 15 N-labelled pseudo-ceramide (SLE). The sample was frozen with liquid nitrogen and cross-sections were cut using a cryomicrotome. As a result, the fine layer structure of the corneocytes was clearly observed by using NanoSIMS. Our studies indicate that SLE penetrates into the stratum corneum via an intercellular route. We conclude that application of NanoSIMS analysis can contribute to a better understanding of the function of cosmetic ingredients in the skin.

Stratum corneum hydration and skin surface pH in patients with atopic dermatitis.

Science.gov (United States)

Knor, Tanja; Meholjić-Fetahović, Ajša; Mehmedagić, Aida

2011-01-01

Atopic dermatitis (AD) is a chronically relapsing skin disease with genetic predisposition, which occurs most frequently in preschool children. It is considered that dryness and pruritus, which are always present in AD, are in correlation with degradation of the skin barrier function. Measurement of hydration and pH value of the stratum corneum is one of the noninvasive methods for evaluation of skin barrier function. The aim of the study was to assess skin barrier function by measuring stratum corneum hydration and skin surface pH of the skin with lesions, perilesional skin and uninvolved skin in AD patients, and skin in a healthy control group. Forty-two patients were included in the study: 21 young and adult AD patients and 21 age-matched healthy controls. Capacitance, which is correlated with hydration of stratum corneum and skin surface pH were measured on the forearm in the above areas by SM810/CM820/pH900 combined units (Courage AND Khazaka, Germany). The mean value of water capacitance measured in AD patients was 44.1 ± 11.6 AU (arbitrary units) on the lesions, 60.2 ± 12.4 AU on perilesional skin and 67.2 ± 8.8 AU on uninvolved skin. In healthy controls, the mean value was 74.1 ± 9.2 AU. The mean pH value measured in AD patients was 6.13 ± 0.52 on the lesions, 5.80 ± 0.41 on perilesional skin, and 5.54 ± 0.49 on uninvolved skin. In control group, the mean pH of the skin surface was 5.24 ± 0.40. The values of both parameters measured on lesional skin were significantly different (capacitance decreased and pH increased) from the values recorded on perilesional skin and uninvolved skin. The same held for the relation between perilesional and uninvolved skin. According to study results, the uninvolved skin of AD patients had significantly worse values of the measured parameters as compared with control group. The results of this study suggested the skin barrier function to be degraded in AD patients, which is specifically expressed in lesional skin.

The impact of ultraviolet therapy on stratum corneum ceramides and barrier function

DEFF Research Database (Denmark)

Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellgren, Lars

2011-01-01

therapy in dermatological patients on ceramides and skin barrier function.We found that UV light treatment does not change the ratio of important stratum corneum lipids, but we confirm earlier findings of decreased susceptibility to irritants after UV- therapy.......The ceramide profile as well as the barrier function is known to be deteriorated in atopic eczema and psoriasis, and ultraviolet (UV) light is known to improve the barrier function. The impact of UV light on ceramides, however, is not clarified.The aim of this study was to examine the effect of UV...

The impact of ultraviolet therapy on stratum corneum ceramides and barrier function

DEFF Research Database (Denmark)

Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellgren, Lars

2011-01-01

therapy in dermatological patients on ceramides and skin barrier function. We found that UV light treatment does not change the ratio of important stratum corneum lipids, but we confirm earlier findings of decreased susceptibility to irritants after UV- therapy.......The ceramide profile as well as the barrier function is known to be deteriorated in atopic eczema and psoriasis, and ultraviolet (UV) light is known to improve the barrier function. The impact of UV light on ceramides, however, is not clarified. The aim of this study was to examine the effect of UV...

Natural moisturizing factors (NMF) in the stratum corneum (SC). I. Effects of lipid extraction and soaking.

Science.gov (United States)

Robinson, Marisa; Visscher, Marty; Laruffa, Angela; Wickett, Randy

2010-01-01

Natural moisturizing factor (NMF) is essential for appropriate stratum corneum hydration, barrier homeostasis, desquamation, and plasticity. It is formed from filaggrin proteolysis to small, hygroscopic molecules including amino acids. We hypothesized that common lipid extraction and soaking in water would alter the level of NMF in the upper SC and its biophysical properties. A novel method of measuring and quantifying the amino acid components of NMF is presented. Adhesive tapes were used to collect samples of the stratum corneum (SC) and were extracted with 6mM perchloric acid for analysis by reverse-phase HPLC. HPLC results were standardized to the amount of protein removed by the tapes. An increase in NMF was found with increased SC depth. Also, the combination of extraction and soaking was found to increase NMF loss relative to control or to extraction or soaking alone. Our results indicate that common skin care practices significantly influence the water binding materials in the upper SC. The findings have implications for the evaluation and formulation of skin care products.

Stratum corneum profiles of inflammatory mediators in patch test reactions to common contact allergens and sodium lauryl sulfate

NARCIS (Netherlands)

Koppes, S. A.; Ljubojevic Hadzavdic, S.; Jakasa, I.; Franceschi, N.; Jurakić Tončić, R.; Marinović, B.; Brans, R.; Gibbs, S.; Frings-Dresen, M. H. W.; Rustemeyer, T.; Kezic, S.

2017-01-01

Background Recent studies have demonstrated allergen-specific differences in the gene expression of inflammatory mediators in patch tested skin. Objectives To determine levels of various inflammatory mediators in the stratum corneum (SC) after patch testing with common contact allergens and the skin

Fatty acids are required for epidermal permeability barrier function.

Science.gov (United States)

Mao-Qiang, M; Elias, P M; Feingold, K R

1993-08-01

The permeability barrier is mediated by a mixture of ceramides, sterols, and free fatty acids arranged as extracellular lamellar bilayers in the stratum corneum. Whereas prior studies have shown that cholesterol and ceramides are required for normal barrier function, definitive evidence for the importance of nonessential fatty acids is not available. To determine whether epidermal fatty acid synthesis also is required for barrier homeostasis, we applied 5-(tetradecyloxy)-2-furancarboxylic acid (TOFA), an inhibitor of acetyl CoA carboxylase, after disruption of the barrier by acetone or tape stripping. TOFA inhibits epidermal fatty acid by approximately 50% and significantly delays barrier recovery. Moreover, coadministration of palmitate with TOFA normalizes barrier recovery, indicating that the delay is due to a deficiency in bulk fatty acids. Furthermore, TOFA treatment also delays the return of lipids to the stratum corneum and results in abnormalities in the structure of lamellar bodies, the organelle which delivers lipid to the stratum corneum. In addition, the organization of secreted lamellar body material into lamellar bilayers within the stratum corneum interstices is disrupted by TOFA treatment. Finally, these abnormalities in lamellar body and stratum corneum membrane structure are corrected by coapplication of palmitate with TOFA. These results demonstrate a requirement for bulk fatty acids in barrier homeostasis. Thus, inhibiting the epidermal synthesis of any of the three key lipids that form the extracellular, lipid-enriched membranes of the stratum corneum results in an impairment in barrier homeostasis.

Presence and persistence of a highly ordered lipid phase state in the avian stratum corneum.

Science.gov (United States)

Champagne, Alex M; Pigg, Victoria A; Allen, Heather C; Williams, Joseph B

2018-06-07

To survive high temperatures in a terrestrial environment, animals must effectively balance evaporative heat loss and water conservation. In passerine birds, cutaneous water loss (CWL) is the primary avenue of water loss at thermoneutral temperatures and increases slightly as ambient temperature increases, indicating a change in the permeability of the skin. In the stratum corneum (SC), the outermost layer of the skin, lipids arranged in layers called lamellae serve as the primary barrier to CWL in birds. The permeability of these lamellae depends in large part on the ability of lipid molecules to pack closely together in an ordered orthorhombic phase state. However, as temperature increases, lipids of the SC become more disordered, and may pack in more permeable hexagonal or liquid crystalline phase states. In this study, we used Fourier transform infrared spectroscopy to monitor the phase state of lipids in the SC of house sparrows ( Passer domesticus ) at skin temperatures ranging from 25 to 50°C. As temperature increased, lipids became slightly more disordered, but remained predominantly in the orthorhombic phase, consistent with the small increase in CWL observed in house sparrows as ambient temperature increases. These results differ considerably from studies on mammalian SC, which find a predominantly hexagonal arrangement of lipids at temperatures above 37°C, and the increased order in avian SC may be explained by longer lipid chain length, scarcity of cholesterol and the presence of cerebrosides. Our results lend further insight into the arrangement and packing of individual lipid molecules in avian SC. © 2018. Published by The Company of Biologists Ltd.

Incomplete KLK7 Secretion and Upregulated LEKTI Expression Underlie Hyperkeratotic Stratum Corneum in Atopic Dermatitis.

Science.gov (United States)

Igawa, Satomi; Kishibe, Mari; Minami-Hori, Masako; Honma, Masaru; Tsujimura, Hisashi; Ishikawa, Junko; Fujimura, Tsutomu; Murakami, Masamoto; Ishida-Yamamoto, Akemi

2017-02-01

Atopic dermatitis (AD) is a common inflammatory skin disorder. Chronic AD lesions present hyperkeratosis, indicating a disturbed desquamation process. KLK7 is a serine protease involved in the proteolysis of extracellular corneodesmosome components, including desmocollin 1 and corneodesmosin, which leads to desquamation. KLK7 is secreted by lamellar granules and upregulated in AD lesional skin. However, despite increased KLK7 protein levels, immunostaining and electron microscopy indicated numerous corneodesmosomes remaining in the uppermost layer of the stratum corneum from AD lesions. We aimed to clarify the discrepancy between KLK7 overexpression and retention of corneodesmosomes on AD corneocytes. Western blot analysis indicated abnormal corneodesmosin degradation patterns in stratum corneum from AD lesions. The KLK activity of tape-stripped corneocytes from AD lesions was not significantly elevated in in situ zymography, which was our new attempt to detect the protease activity more precisely than conventional assays. This ineffective KLK activation was associated with impaired KLK7 secretion from lamellar granules and increased expression of LEKTI in AD. Such imbalances in protease-protease inhibitor interactions could lead to abnormal proteolysis of corneodesmosomes and compact hyperkeratosis. Upregulated expression of LEKTI might be a compensatory mechanism to prevent further barrier dysfunction in AD. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Lecithin-based microemulsions for targeted delivery of ceramide AP into the stratum corneum: formulation, characterizations, and in vitro release and penetration studies.

Science.gov (United States)

Sahle, Fitsum F; Metz, Hendrik; Wohlrab, Johannes; Neubert, Reinhard H H

2013-02-01

To improve the solubility and penetration of Ceramide AP (CER [AP]) into the stratum corneum that potentially restores the barrier function of aged and affected skin. CER [AP] microemulsions (MEs) were formulated using lecithin, Miglyol® 812 (miglyol) and water-1,2 pentandiol (PeG) mixture as amphiphilic, oily and hydrophilic components, respectively. The nanostructure of the MEs was revealed using electrical conductivity, differential scanning calorimeter (DSC) and electron paramagnetic resonance (EPR) techniques. Photon correlation spectroscopy (PCS) was used to measure the sizes and shape of ME droplets. The release and penetration of the CER into the stratum corneum was investigated in vitro using a multi-layer membrane model. The MEs exhibited excellent thermodynamic stability (>2 years) and loading capacity (0.5% CER [AP]). The pseudo-ternary phase diagrams of the MEs were obtained and PCS results showed that the droplets are spherical in shape and bigger in size. In vitro investigations showed that the MEs exhibited excellent rate and extent of release and penetration. Stable lecithin-based CER [AP] MEs that significantly enhance the solubility and penetration of CER [AP] into the stratum corneum were developed. The MEs also have better properties than the previously reported polyglycerol fatty acid surfactant-based CER [AP] MEs.

Dew point effect of cooled hydrogel pads on human stratum corneum biosurface.

Science.gov (United States)

Xhauflaire-Uhoda, Emmanuelle; Paquet, Philippe; Piérard, Gérald E

2008-01-01

Cooled hydrogel pads are used to prevent overheating effects of laser therapy. They do not induce cold injuries to the skin, but their more subtle physiological effects have not been thoroughly studied. To describe the changes in transepidermal water loss and electrometric properties of the skin surface following application of cooled hydrogel pads. Measurements were performed on normal forearm skin of 27 healthy volunteers and on freshly excised skin from abdominoplasty. LaserAid hydrogel pads cooled to 4 degrees C were placed for 15 min on the forearm skin. Measurements of transepidermal water loss (TEWL) and electrometric properties (Corneometer, Nova DPM 900) were performed before application and after removal of the cooled pads. A consistent increase in corneometer units, dermal phase meter (DPM) values and TEWL were recorded at removal of the cooled hydrogel pads. Both the in vivo and in vitro assessments brought similar information. The similar changes disclosed in vitro and in vivo suggest that a common physical process is operating in these conditions. The observed phenomenon is opposite to the predicted events given by the Arrhenius law probably because of the combination of cooling and occlusion by the pads. A dew point effect (air temperature at which relative humidity is maximal) is likely involved in the moisture content of the stratum corneum. Thus, the biological impact of using cooling hydrogel pads during laser therapy is different from the effect of a cryogenic spray cooling procedure. The better preservation of the water balance in the stratum corneum by the cooled hydrogel pads could have a beneficial esthetic effect on laser treated areas. (c) 2008 S. Karger AG, Basel.

Influence of DMPS on the water retention capacity of electroporated stratum corneum: ATR-FTIR study.

Science.gov (United States)

Sckolnick, Maria; Hui, Sek-Wen; Sen, Arindam

2008-02-28

Anionic lipids like phosphatidylserine are known to significantly enhance electroporation mediated transepidermal transport of polar solutes of molecular weights up to 10kDa. The underlying mechanism of the effect of anionic lipids on transdermal transport is not fully understood. The main barrier to transdermal transport lies within the intercellular lipid matrix (ILM) of the stratum corneum (SC) and our previous studies indicate that dimyristoyl phosphatidylserine (DMPS) can perturb the packing of this lipid matrix. Here we report on our investigation on water retention in the SC following electroporation in the presence and the absence of DMPS. The water content in the outer most layers of the SC of full thickness porcine skin was determined using ATR-FTIR-spectroscopy. The results show that in the presence of DMPS, the SC remains in a state of enhanced hydration for longer periods after electroporation. This increase in water retention in the SC by DMPS is likely to play an important role in trans-epidermal transport, since improved hydration of the skin barrier can be expected to increase the partitioning of polar solutes and possibly the permeability.

Sun-Induced Changes in Stratum Corneum Function Are Gender and Dose Dependent in a Chinese Population

Science.gov (United States)

Liu, Z.; Fluhr, J.W.; Song, S.P.; Sun, Z.; Wang, H.; Shi, Y.J.; Elias, P.M.; Man, M.-Q.

2010-01-01

Previous studies have demonstrated that UVB radiation changes the epidermal permeability barrier and stratum corneum (SC) hydration. It is well known that sun exposure causes erythema, sunburn and melanoma. However, whether daily sun exposure alters SC integrity and epidermal permeability barrier function is largely unknown, especially in Chinese subjects. In the present study, we assess the SC integrity, SC hydration and epidermal permeability barrier function following various doses of sun exposure. A total of 258 subjects (124 males and 134 females) aged 18–50 years were enrolled. A multifunctional skin physiology monitor (Courage & Khazaka MPA5) was used to measure SC hydration and transepidermal water loss (TEWL) on the forearms. In males, basal TEWL was higher with higher doses of sun exposure than with lower doses and control, whereas in females, basal TEWL was higher with lower doses of sun exposure than with higher doses and control. In the group with higher doses of sun exposure, TEWL in females was significantly lower than that in males. The barrier recovery was faster in females than in males in both control and lower-dose groups. In both males and females, barrier recovery was delayed with higher doses of sun exposure. In males, sun exposure did not alter SC hydration, while in females SC hydration was lower with lower doses of sun exposure as compared with control and higher doses of sun exposure. These results demonstrated that sun-induced changes in SC function and SC hydration vary with gender and the extent of sun exposure. PMID:20571289

Deposits from Creams Containing 20% (w/w) Urea and Suppression of Crystallization (Part 2): Novel Analytical Methods of Urea Accumulated in the Stratum Corneum by Tape stripping and Colorimetry.

Science.gov (United States)

Goto, Norio; Morita, Yutaka; Terada, Katsuhide

2016-01-01

The transfer of urea from a urea formulation to the stratum corneum varies with the formulation base and form, and impacts the formulation's therapeutic effect. Consequently, determining the amount of urea transferred is essential for developing efficient formulations. This study assessed a simple method for measuring the amount of urea accumulated in the stratum corneum. Conventional methods rely on labeling urea used in the formulation with radiocarbon ((14)C) or other radioactive isotopes (RIs), retrieving the transferred urea from the stratum corneum by tape stripping, then quantitating the urea. The handling and use of RIs, however, is subject to legal regulation and can only be performed in sanctioned facilities, so methods employing RIs are neither simple nor convenient. We therefore developed a non-radiolabel method "tape stripping-colorimetry (T-C)" that combines tape stripping with colorimetry (urease-glutamate dehydrogenase (GLDH)) for the quantitative measurement of urea. Urea in the stratum corneum is collected by tape stripping and measured using urease-GLDH, which is commonly used to measure urea nitrogen in blood tests. The results indicate that accurate urea measurement by the T-C method requires the application of 1400 mg (on hairless rats) of a 20% urea solution on a 50 cm(2) (5×10 cm) area. Further, we determined the amount of urea accumulated in the stratum corneum using formulations with different urea concentrations, and the time course of urea accumulation from formulations differing in the rate of urea crystallization. We demonstrate that the T-C method is simple and convenient, with no need for (14)C or other RIs.

Sun-induced changes of stratum corneum hydration vary with age and gender in a normal Chinese population.

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Liu, Zhili; Song, Shunpeng; Luo, Wenhai; Elias, Peter M; Man, Mao-Qiang

2012-02-01

Previous studies have demonstrated that sun-induced alteration of epidermal permeability barrier function varies with gender and age. In the present study, we assess the stratum corneum (SC) hydration in sun-exposed males and females. A total of 168 subjects (84 males and 84 females) aged 19-75 years were enrolled. A multifunctional skin physiology monitor was used to measure SC hydration. In comparison with non-sun exposure, sun exposure does not cause a significant change in SC hydration in either young males or young females, whereas in aged females, a significant reduction of SC hydration is seen on the forehead and the dorsal hand of sun-exposed subjects. SC hydration on the canthus of both aged males and aged females is significantly lower than that of young subjects. Additionally, SC hydration on the dorsal hand of aged females is also significantly lower as compared with young females. Sun-induced reduction of SC hydration is more evident on the dorsal hand of aged females than that of males (Phydration property vary with age and gender. © 2011 John Wiley & Sons A/S.

Modelling Formation of a Drug Reservoir in the Stratum Corneum and Its Impact on Drug Monitoring Using Reverse Iontophoresis

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Yvonne Paulley

2010-01-01

Full Text Available Reverse iontophoresis is a relatively new technique for non-invasive drug monitoring in the body. It involves a small electrical current being passed through the skin to facilitate the movement of small charged ions and polar molecules on the skin's surface where the amount of drug can then be measured and hence an accurate estimate of the blood concentration can be made. In vivo studies for several molecules show that initially large amounts of drug are extracted from the body, which are unrelated to the magnitude of the blood concentration; over time the fluxes of extraction decrease to a level proportional to the steady state blood concentration. This suggests that, at first, the drug is being extracted from some source other than the blood; one such candidate for this source is the dead cells which form the stratum corneum. In this paper, we construct two related mathematical models; the first describes the formation of the drug reservoir in the stratum corneum as a consequence of repeated drug intake and natural death of skin cells in the body. The output from this model provides initial conditions for the model of reverse iontophoresis in which charged ions from both the blood and the stratum corneum reservoir compete for the electric current. Model parameters are estimated from data collected for lithium monitoring. Our models will improve interpretation of reverse iontophoretic data by discriminating the subdermal from the skin contribution to the fluxes of extraction. They also suggest that analysis of the skin reservoir might be a valuable tool to investigate patients' exposure to chemicals including therapeutic drugs.

Vehicle effects on human stratum corneum absorption and skin penetration.

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Zhang, Alissa; Jung, Eui-Chang; Zhu, Hanjiang; Zou, Ying; Hui, Xiaoying; Maibach, Howard

2017-05-01

This study evaluated the effects of three vehicles-ethanol (EtOH), isopropyl alcohol (IPA), and isopropyl myristate (IPM)-on stratum corneum (SC) absorption and diffusion of the [ 14 C]-model compounds benzoic acid and butenafine hydrochloride to better understand the transport pathways of chemicals passing through and resident in SC. Following application of topical formulations to human dermatomed skin for 30 min, penetration flux was observed for 24 h post dosing, using an in vitro flow-through skin diffusion system. Skin absorption and penetration was compared to the chemical-SC (intact, delipidized, or SC lipid film) binding levels. A significant vehicle effect was observed for chemical skin penetration and SC absorption. IPA resulted in the greatest levels of intact SC/SC lipid absorption, skin penetration, and total skin absorption/penetration of benzoic acid, followed by IPM and EtOH, respectively. For intact SC absorption and total skin absorption/penetration of butenafine, the vehicle that demonstrated the highest level of sorption/penetration was EtOH, followed by IPA and IPM, respectively. The percent doses of butenafine that were absorbed in SC lipid film and penetrated through skin in 24 h were greatest for IPA, followed by EtOH and IPM, respectively. The vehicle effect was consistent between intact SC absorption and total chemical skin absorption and penetration, as well as SC lipid absorption and chemical penetration through skin, suggesting intercellular transport as a main pathway of skin penetration for model chemicals. These results suggest the potential to predict vehicle effects on skin permeability with simple SC absorption assays. As decontamination was applied 30 min after chemical exposure, significant vehicle effects on chemical SC partitioning and percutaneous penetration also suggest that skin decontamination efficiency is vehicle dependent, and an effective decontamination method should act on chemical solutes in the lipid domain.

Skin barrier response to occlusion of healthy and irritated skin: Differences in trans-epidermal water loss, erythema and stratum corneum lipids

DEFF Research Database (Denmark)

Jungersted, J.M.; Høgh, Julie Kaae; Hellgren, Lars

2010-01-01

been damaged by either sodium lauryl sulfate (SLS) or tape stripping, respectively, was determined and compared with that of to non-occluded pre-damaged skin. Skin barrier function was assessed by measurements of trans-epidermal water loss (TEWL) and erythema. In study A, stratum corneum lipids were...

The Permeability Enhancing Mechanism of DMSO in Ceramide Bilayers Simulated by Molecular Dynamics

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Notman, Rebecca; den Otter, Wouter K.; Noro, Massimo G.; Briels, W. J.; Anwar, Jamshed

2007-01-01

The lipids of the topmost layer of the skin, the stratum corneum, represent the primary barrier to molecules penetrating the skin. One approach to overcoming this barrier for the purpose of delivery of active molecules into or via the skin is to employ chemical permeability enhancers, such as dimethylsulfoxide (DMSO). How these molecules exert their effect at the molecular level is not understood. We have investigated the interaction of DMSO with gel-phase bilayers of ceramide 2, the predominant lipid in the stratum corneum, by means of molecular dynamics simulations. The simulations satisfactorily reproduce the phase behavior and the known structural parameters of ceramide 2 bilayers in water. The effect of DMSO on the gel-phase bilayers was investigated at various concentrations over the range 0.0−0.6 mol fraction DMSO. The DMSO molecules accumulate in the headgroup region and weaken the lateral forces between the ceramides. At high concentrations of DMSO (≥0.4 mol fraction), the ceramide bilayers undergo a phase transition from the gel phase to the liquid crystalline phase. The liquid-crystalline phase of ceramides is expected to be markedly more permeable to solutes than the gel phase. The results are consistent with the experimental evidence that high concentrations of DMSO fluidize the stratum corneum lipids and enhance permeability. PMID:17513383

Assessing the relationship between vitamin D3 and stratum corneum hydration for the treatment of xerotic skin.

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Russell, Meghan

2012-09-01

Vitamin D(3) has been called the "sunshine" vitamin since the formation of vitamin D is mediated by exposure to sunlight. Vitamin D(3) is linked to many health benefits, however serum levels of vitamin D(3) have been decreasing over the last few decades and the lower levels of vitamin D(3) may have consequences on normal physiology. We investigated the association between serum 25-hydroxyvitamin D (25(OH)D) levels and stratum corneum conductance as well as the effect of topical application of cholecalciferol (vitamin D(3)) on dry skin. Eighty three subjects were recruited and blood serum levels and skin conductance measurements were taken after a one week washout. A correlation was observed between vitamin D levels and skin moisture content, individuals with lower levels of vitamin D had lower average skin moisture. Subsequently, a 3-week split leg, randomized, vehicle controlled clinical study was conducted on a subset of 61 of the above individuals who were identified with non-sufficient vitamin D serum levels. Topical supplementation with cholecalciferol significantly increased measurements of skin moisturization and resulted in improvements in subjective clinical grading of dry skin. Taken together our finding suggest a relationship between serum vitamin D(3) (25(OH)D) levels and hydration of the stratum corneum and further demonstrate the skin moisture benefit from topical application of vitamin D(3).

[Impact of wet work on epidermal barrier (tewl and stratum corneum hydration) and skin viscoelasticity in nurses].

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Kieć-Świcrczyńska, Marta; Chomiczewska-Skóra, Dorota; Świerczyńska-Machura, Dominika; Kręcisz, Beata

2014-01-01

Nurses are prone to develop hand eczema due to occupational exposure to irritants, including wet work. The aim of the study was to evaluate the impact of wet work on selected skin properties, reflecting epidermal barrier function--transepidermal water loss (TEWL) and stratum corneum hydration--and additionally skin viscoelasticity, in nurses. Study subjects included 90 nurses employed in hospital wards. Measurements were carried out within the dorsal aspect of the dominant hand, using a Cutometer MPA 580 equipped with Tewameter TM 300 and Corneometer CM 825 (Courage & Khazaka, Germany) probes. Examina- tions took place on hospital premises. Similar measurements were performed in the control group of females non-exposed to irritants. In the examined group of nurses, mean TEWL was 15.5 g/h/m2 and was higher than in the control group (12.99 g/h/m2). After rejecting the extreme results, the difference between the groups proved to be statistically significant (p hydration was lower in the examined group (37.915) compared with the control group (40.05), but the difference was not sta tistically significant. Also results of viscoelasticity assessment showed no significant differences between studied groups. The results of the assessment of skin biophysical properties show that wet work exerts a moderately adverse impact on skin condition. A higher TEWL value and a lower stratum corneum hydration in workers exposed to irritants reflect an adverse impact of these factors on the epidermal barrier function.

Sunscreens with broad-spectrum absorption decrease the trans TO cis photoisomerization of urocanic acid in the human stratum corneum after multiple UV light exposures

International Nuclear Information System (INIS)

Krien, P.M.; Moyal, D.

1994-01-01

The trans to cis photoisomerization of urocanic acid (UCA) in skin is considered to play an important role in the mechanism of immunosuppression. We have investigated the effects of skin type and various sunscreens with low sun protection factor (SPF) on the UV-induced cis-UCA formation in human skin after exposure to artificial UV light. The rate of cis-UCA formation depends little on the skin type and is reduced by topical application of sunscreens. The rate of cis-UCA formation decreases with increasing SPF and only broad-spectrum, highly protective sunscreens offer protection against the UV-induced formation of cis-UCA, which accumulates in the stratum corneum after multiple UV exposures. A theoretical approach to estimate the distribution of cis-UCA after irradiation indicates that this compound may diffuse into the deeper layers of the epidermis with D ∼ 10 -17 m 2 /s, and that its elimination from the stratum corneum is mainly due to desquamation. (author)

Electroperturbation of human stratum corneum fine structure by high voltage pulses: a freeze-fracture electron microscopy and differential thermal analysis study.

Science.gov (United States)

Jadoul, A; Tanojo, H; Préat, V; Bouwstra, J A; Spies, F; Boddé, H E

1998-08-01

Application of high voltage pulses (HVP) to the skin has been shown to promote the transdermal drug delivery by a mechanism involving skin electroporation. The aim of this study was to detect potential changes in lipid phase and ultrastructure induced in human stratum corneum by various HVP protocols, using differential thermal analysis and freeze-fracture electron microscopy. Due to the time involved between the moment the electric field is switched off and the analysis, only "secondary" phenomena rather than primary events could be observed. A decrease in enthalpies for the phase transitions observed at 70 degrees C and 85 degrees C was detected by differential thermal analysis after HVP treatment. No changes in transition temperature could be seen. The freeze-fracture electron microscopy study revealed a dramatic perturbation of the lamellar ordering of the intercellular lipid after application of HVP. Most of the planes displayed rough surfaces. The lipid lamellae exhibited rounded off steps or a vanished stepwise order. There was no evidence for perturbation of the corneocytes content. In conclusion, the freeze-fracture electron microscopy and differential thermal analysis studies suggest that HVP application induces a general perturbation of the stratum corneum lipid ultrastructure.

In vivo studies of aquaporins 3 and 10 in human stratum corneum

DEFF Research Database (Denmark)

Jungersted, Jakob Mutanu; Bomholt, Julie; Bajraktari, Niada

2013-01-01

migration and proliferation with consequences for the antimicrobial defense of the skin. AQP3 and AQP10 are aqua-glyceroporins, known to transport glycerol as well as water. AQP3 is the predominant AQP in human skin and has previously been demonstrated in the basal layer of epidermis in normal human skin......, but not in stratum corneum (SC). AQP10 has not previously been identified in human skin. Previous studies have demonstrated the presence of AQP3 and AQP10 mRNA in keratinocytes. In this study, our aim was to investigate if these aquaporin proteins were actually present in human SC cells. This can be seen as a first...... step toward elucidating the possible functional role of AQP3 and AQP10 in SC hydration. Specifically we investigate the presence of AQP3 and AQP10 in vivo in human SC using “minimal-invasive” technique for obtaining SC samples. SC samples were obtained from six healthy volunteers. Western blotting...

From observational to analytical morphology of the stratum corneum: progress avoiding hazardous animal and human testings

Directory of Open Access Journals (Sweden)

Piérard GE

2015-03-01

Full Text Available Gérald E Piérard,1,2 Justine Courtois,1 Caroline Ritacco,1 Philippe Humbert,2,3 Ferial Fanian,3 Claudine Piérard-Franchimont1,4,5 1Laboratory of Skin Bioengineering and Imaging (LABIC, Department of Clinical Sciences, Liège University, Liège, Belgium; 2University of Franche-Comté, Besançon, France; 3Department of Dermatology, University Hospital Saint-Jacques, Besançon, France; 4Department of Dermatopathology, Unilab Lg, University Hospital of Liège, Liège, Belgium; 5Department of Dermatology, Regional Hospital of Huy, Huy, Belgium Background: In cosmetic science, noninvasive sampling of the upper part of the stratum corneum is conveniently performed using strippings with adhesive-coated discs (SACD and cyanoacrylate skin surface strippings (CSSSs. Methods: Under controlled conditions, it is possible to scrutinize SACD and CSSS with objectivity using appropriate methods of analytical morphology. These procedures apply to a series of clinical conditions including xerosis grading, comedometry, corneodynamics, corneomelametry, corneosurfametry, corneoxenometry, and dandruff assessment. Results: With any of the analytical evaluations, SACD and CSSS provide specific salient information that is useful in the field of cosmetology. In particular, both methods appear valuable and complementary in assessing the human skin compatibility of personal skincare products. Conclusion: A set of quantitative analytical methods applicable to the minimally invasive and low-cost SACD and CSSS procedures allow for a sound assessment of cosmetic effects on the stratum corneum. Under regular conditions, both methods are painless and do not induce adverse events. Globally, CSSS appears more precise and informative than the regular SACD stripping. Keywords: irritation, morphometry, quantitative morphology, stripping

Hydration effects on the barrier function of stratum corneum lipids: Raman analysis of ceramides 2, III and 5.

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Tfayli, Ali; Jamal, Dima; Vyumvuhore, Raoul; Manfait, Michel; Baillet-Guffroy, Arlette

2013-11-07

The stratum corneum is the outermost layer of the skin; its barrier function is highly dependent on the composition and the structure as well as the organization of lipids in its extracellular matrix. Ceramides, free fatty acids and cholesterol represent the major lipid classes present in this matrix. They play an important role in maintaining the normal hydration levels required for the normal physiological function. Despite the advancement in the understanding of the structure, composition and the function of the stratum corneum (SC), the concern of "dry skin" remains important in dermatology and care research. Most studies focus on the quantification of water in the skin using different techniques including Raman spectroscopy, while the studies that investigate the effect of hydration on the quality of the barrier function of the skin are limited. Raman spectroscopy provides structural, conformational and organizational information that could help elucidate the effect of hydration on the barrier function of the skin. In order to assess the effect of relative humidity on the lipid barrier function; we used Raman spectroscopy to follow-up the evolution of the conformation and the organization of three synthetic ceramides (CER) differing from each other by the nature of their polar heads (sphingosine, phytosphingosine and α hydroxyl sphingosine), CER 2, III and 5 respectively. CER III and 5 showed a more compact and ordered organization with stronger polar interactions at intermediate relative humidity values, while CER 2 showed opposite tendencies to those observed with CER III and 5.

Effect of chemical permeation enhancers on stratum corneum barrier lipid organizational structure and interferon alpha permeability.

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Moghadam, Shadi H; Saliaj, Evi; Wettig, Shawn D; Dong, Chilbert; Ivanova, Marina V; Huzil, J Torin; Foldvari, Marianna

2013-06-03

The outermost layer of the skin, known as the stratum corneum (SC), is composed of dead corneocytes embedded in an intercellular lipid matrix consisting of ceramides, free fatty acids, and cholesterol. The high level of organization within this matrix protects the body by limiting the permeation of most compounds through the skin. While essential for its protective functions, the SC poses a significant barrier for the delivery of topically applied pharmaceutical agents. Chemical permeation enhancers (CPEs) can increase delivery of small drug compounds into the skin by interacting with the intercellular lipids through physical processes including extraction, fluidization, increased disorder, and phase separation. However, it is not clear whether these same mechanisms are involved in delivery of biotherapeutic macromolecules, such as proteins. Here we describe the effect of three categories of CPEs {solvents [ethanol, propylene glycol, diethylene glycol monoethyl ether (transcutol), oleic acid], terpenes [menthol, nerol, camphor, methyl salicylate], and surfactants [Tween 80, SDS, benzalkonium chloride, polyoxyl 40 hydrogenated castor oil (Cremophor RH40), didecyldimethylammonium bromide (DDAB), didecyltrimethylammonium bromide (DTAB)]} on the lipid organizational structure of human SC as determined by X-ray scattering studies. Small- and wide-angle X-ray scattering studies were conducted to correlate the degree of structural changes and hydrocarbon chain packing in SC lipids caused by these various classes of CPEs to the extent of permeation of interferon alpha-2b (IFNα), a 19 kDa protein drug, into human skin. With the exception of solvents, propylene glycol and ethanol, all classes of CPEs caused increased disordering of lamellar and lateral packing of lipids. We observed that the highest degree of SC lipid disordering was caused by surfactants (especially SDS, DDAB, and DTAB) followed by terpenes, such as nerol. Interestingly, in vitro skin permeation studies

Investigation of cis-trans isomer dependent dermatotoxicokinetics of UV filter ethylhexyl methoxycinnamate through stratum corneum in vivo.

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Sharma, Anežka; Bányiová, Katarína; Vrana, Branislav; Justan, Ivan; Čupr, Pavel

2017-11-01

2-Ethylhexyl methoxycinnamate (EHMC) is one of the most used ultraviolet filters in personal care products. It undergoes cis/trans isomerization in sunlight, and there is limited toxicological understanding of the effects of the cis-isomer. It is known that two geometric isomers of one compound can have different physico-chemical properties and effects. However, there are no studies focusing on toxicokinetics of EHMC isomerization products to compare their potential difference in dermal exposure to cis-EHMC and trans-EHMC due to the difference in their dermatotoxicokinetics. In this study, dermal absorption of the parental trans-EHMC and its cis isomer was studied. A commercially available sunscreen lotion containing trans-EHMC and spiked with laboratory-prepared cis-EHMC was locally applied on the forearm skin of two volunteers. After 8 h of skin exposure, the stratum corneum (SC) layer was removed by tape stripping. The removed thickness of the SC was determined spectrophotometrically using a total protein assay. The concentration of both isomers in the removed SC was measured by HPLC-DAD. A new diffusion and permeability coefficient of both EHMC isomers in SC were determined by Fick's second law of diffusion in vivo. The difference in dermatotoxicokinetic parameters between the two isomers was not statistically significant. However, separate toxicological studies of isomeric forms and the determination of their dermatotoxicokinetic parameters are crucial for refinement of human risk assessment.

How Sensitive Are Transdermal Transport Predictions by Microscopic Stratum Corneum Models to Geometric and Transport Parameter Input?

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Wen, Jessica; Koo, Soh Myoung; Lape, Nancy

2018-02-01

While predictive models of transdermal transport have the potential to reduce human and animal testing, microscopic stratum corneum (SC) model output is highly dependent on idealized SC geometry, transport pathway (transcellular vs. intercellular), and penetrant transport parameters (e.g., compound diffusivity in lipids). Most microscopic models are limited to a simple rectangular brick-and-mortar SC geometry and do not account for variability across delivery sites, hydration levels, and populations. In addition, these models rely on transport parameters obtained from pure theory, parameter fitting to match in vivo experiments, and time-intensive diffusion experiments for each compound. In this work, we develop a microscopic finite element model that allows us to probe model sensitivity to variations in geometry, transport pathway, and hydration level. Given the dearth of experimentally-validated transport data and the wide range in theoretically-predicted transport parameters, we examine the model's response to a variety of transport parameters reported in the literature. Results show that model predictions are strongly dependent on all aforementioned variations, resulting in order-of-magnitude differences in lag times and permeabilities for distinct structure, hydration, and parameter combinations. This work demonstrates that universally predictive models cannot fully succeed without employing experimentally verified transport parameters and individualized SC structures. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Role of lipids in the formation and maintenance of the cutaneous permeability barrier.

Science.gov (United States)

Feingold, Kenneth R; Elias, Peter M

2014-03-01

The major function of the skin is to form a barrier between the internal milieu and the hostile external environment. A permeability barrier that prevents the loss of water and electrolytes is essential for life on land. The permeability barrier is mediated primarily by lipid enriched lamellar membranes that are localized to the extracellular spaces of the stratum corneum. These lipid enriched membranes have a unique structure and contain approximately 50% ceramides, 25% cholesterol, and 15% free fatty acids with very little phospholipid. Lamellar bodies, which are formed during the differentiation of keratinocytes, play a key role in delivering the lipids from the stratum granulosum cells into the extracellular spaces of the stratum corneum. Lamellar bodies contain predominantly glucosylceramides, phospholipids, and cholesterol and following the exocytosis of lamellar lipids into the extracellular space of the stratum corneum these precursor lipids are converted by beta glucocerebrosidase and phospholipases into the ceramides and fatty acids, which comprise the lamellar membranes. The lipids required for lamellar body formation are derived from de novo synthesis by keratinocytes and from extra-cutaneous sources. The lipid synthetic pathways and the regulation of these pathways are described in this review. In addition, the pathways for the uptake of extra-cutaneous lipids into keratinocytes are discussed. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias. Published by Elsevier B.V.

Stratum corneum lipids, skin barrier function and filaggrin mutations in patients with atopic eczema

DEFF Research Database (Denmark)

Høgh, Julie Kaae; Hellgren, Lars; Jungersted, JM

2010-01-01

chromatography. In addition, TEWL, erythema, skin hydration and pH were measured. In 27 of the 49 individuals, a 24-h irritation patch test with sodium lauryl sulphate was performed. For the analysis, both the AD group and the control group were stratified by FLG mutation status (FLGmut/FLGwt). Results......Background: Prior to the discovery of filaggrin (FLG) mutations, evidence for an impaired skin barrier in atopic dermatitis (AD) has been documented, and changes in ceramide profile, altered skin pH and increased trans-epidermal water loss (TEWL) in patients with AD have been reported. Until now......, no studies have analysed stratum corneum (SC) lipids combined with skin barrier parameters in subjects of known FLG genotype. Methods: A cohort of 49 German individuals genotyped for the most common FLG mutations (R501X, 2282del4) had SC samples taken for lipid analysis by high-performance thin layer...

The important role of stratum corneum lipids for the cutaneous barrier function.

Science.gov (United States)

van Smeden, J; Janssens, M; Gooris, G S; Bouwstra, J A

2014-03-01

The skin protects the body from unwanted influences from the environment as well as excessive water loss. The barrier function of the skin is located in the stratum corneum (SC). The SC consists of corneocytes embedded in a lipid matrix. This lipid matrix is crucial for the lipid skin barrier function. This paper provides an overview of the reported SC lipid composition and organization mainly focusing on healthy and diseased human skin. In addition, an overview is provided on the data describing the relation between lipid modulations and the impaired skin barrier function. Finally, the use of in vitro lipid models for a better understanding of the relation between the lipid composition, lipid organization and skin lipid barrier is discussed. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias. Copyright © 2013 Elsevier B.V. All rights reserved.

Penetration of gold nanoparticles across the stratum corneum layer of thick-Skin.

Science.gov (United States)

Raju, Gayathri; Katiyar, Neeraj; Vadukumpully, Sajini; Shankarappa, Sahadev A

2018-02-01

Transdermal particulate penetration across thick-skin, such as that of palms and sole, is particularly important for drug delivery for disorders such as small fiber neuropathies. Nanoparticle-based drug delivery across skin is believed to have much translational applications, but their penetration especially through thick-skin, is not clear. This study specifically investigates the effectiveness of gold nanoparticles (AuNPs) for thick-skin penetration, especially across the stratum corneum (SC) as a function of particle size. The thick-skinned hind-paw of rat was used to characterize depth and distribution of AuNPs of varying sizes, namely, 22±3, 105±11, and 186±20nm. Epidermal penetration of AuNPs was characterized both, in harvested skin from the hind-paw using a diffusion chamber, as well as in vivo. Harvested skin segments exposed to 22nm AuNPs for only 3h demonstrated higher penetration (pthick-skin allows nanoparticle penetration and acts as a depot for release of AuNPs into circulation long after the initial exposure has ceased. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Evaluation of the interaction of surfactants with stratum corneum model membrane from Bothrops jararaca by DSC.

Science.gov (United States)

Baby, André Rolim; Lacerda, Aurea Cristina Lemos; Velasco, Maria Valéria Robles; Lopes, Patrícia Santos; Kawano, Yoshio; Kaneko, Telma Mary

2006-07-06

The interaction of surfactants sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium chloride (CTAC) and lauryl alcohol ethoxylated (12 mol ethylene oxide) (LAE-12OE) was evaluated on the stratum corneum (SC) of shed snake skins from Bothrops jararaca, used as model membrane, and thermal characterized by differential scanning calorimetry (DSC). Surfactant solutions were employed above of the critical micellar concentration (CMC) with treatment time of 8h. The SDS interaction with the SC model membrane has increased the characteristic transition temperature of 130 degrees C in approximately 10 degrees C for the water loss and keratin denaturation, indicating an augmentation of the water content. Samples treated with CTAC have a decrease of the water loss temperature, while, for the LAE-12OE treated samples, changes on the transition temperature have not been observed.

Herbal medicines that benefit epidermal permeability barrier function

Directory of Open Access Journals (Sweden)

Lizhi Hu

2015-06-01

Full Text Available Epidermal permeability barrier function plays a critical role in regulating cutaneous functions. Hence, researchers have been searching for effective and affordable regimens to enhance epidermal permeability barrier function. In addition to topical stratum corneum lipids, peroxisome proliferator-activated receptor, and liver X receptor ligands, herbal medicines have been proven to benefit epidermal permeability barrier function in both normal and diseased skin, including atopic dermatitis, glucocorticoid-induced skin damage, and UVB-damaged skin. The potential mechanisms by which herbal medicines improve the permeability barrier include stimulation of epidermal differentiation, lipid production, antimicrobial peptide expression, and antioxidation. Therefore, utilization of herbal medicines could be a valuable alternative approach to enhance epidermal permeability barrier function in order to prevent and/or treat skin disorders associated with permeability barrier abnormalities.

Stratum corneum cytokines and skin irritation response to sodium lauryl sulfate.

Science.gov (United States)

De Jongh, Cindy M; Verberk, Maarten M; Withagen, Carien E T; Jacobs, John J L; Rustemeyer, Thomas; Kezic, Sanja

2006-06-01

Little is known about cytokines involved in chronic irritant contact dermatitis. Individual cytokine profiles might explain at least part of the differences in the individual response to irritation. Our objective was to investigate the relation between baseline stratum corneum (SC) cytokine levels and the skin response to a single and a repeated irritation test. This study also aimed to determine changes in SC cytokine levels after repeated irritation. Transepidermal water loss (TEWL) and erythema were measured in 20 volunteers after single 24-hr exposure to 1% sodium lauryl sulfate (SLS), and during and after repeated exposure to 0.1% SLS over a 3-week period. SC cytokine levels were measured from an unexposed skin site and from the repeatedly exposed site. Interleukin (IL)-1alpha decreased by 30% after repeated exposure, while IL-1RA increased 10-fold and IL-8 increased fourfold. Baseline IL-1RA and IL-8 values were predictors of TEWL and erythema after single exposure (r = 0.55-0.61). 6 subjects showed barrier recovery during repeated exposure. Baseline IL-1RA and IL-8 levels are likely to be indicators of higher skin irritability after single exposure to SLS. Barrier repair in some of the subjects might explain the lack of agreement between the TEWL response after single and repeated irritation.

Differences in the stratum corneum of Indonesian infants and adults

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Tsutomu Fujimura

2017-02-01

Full Text Available Background Although understanding the stratum corneum (SC of infant skin is important to avoid skin diseases such as atopic dermatitis, there has been no such investigation in Indonesian infants to date. Objective  To obtain a basic knowledge of SC characteristics in Indonesian infants in order to develop methods for infant-specific skin care and to prevent dermatitis and infection. Methods Seventy-two healthy, full term infants aged 1 to 24 months who were native Indonesians residing in Jakarta were enrolled in this study. Some of the mothers were also enrolled in the study as adults (n=30. Transepidermal water loss (TEWL and hydration of the SC (capacitance on the thigh, buttock, and upper arm were measured after sufficient acclimation in an air-conditioned room, in both infants and mothers. Results The SC hydration was significantly higher in infants than adults at all sites measured, including the buttocks, which is a diaper area. Infant TEWL values were also significantly higher than in adults at all sites. Hydration of the SC and TEWL values showed no significant correlation with age of infant for any site. The SC hydration and TEWL values of Indonesian infants did not decrease to adult values within 24 months, which indicates that the SC characteristics in infants continue to develop after 24 months of age. Conclusion  Indonesian infants aged 0-24 months have significantly higher SC hydration and TEWL values than Indonesian mothers. However, infant age has no correlation to SC hydration or to TEWL values.

Defects in Stratum Corneum Desquamation Are the Predominant Effect of Impaired ABCA12 Function in a Novel Mouse Model of Harlequin Ichthyosis.

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Lei Zhang

Full Text Available Harlequin Ichthyosis is a severe skin disease caused by mutations in the human gene encoding ABCA12. Here, we characterize a novel mutation in intron 29 of the mouse Abca12 gene that leads to the loss of a 5' splice donor site and truncation of the Abca12 RNA transcript. Homozygous mutants of this smooth skin or smsk allele die perinatally with shiny translucent skin, typical of animal models of Harlequin Ichthyosis. Characterization of smsk mutant skin showed that the delivery of glucosylceramides and CORNEODESMOSIN was defective, while ultrastructural analysis revealed abnormal lamellar bodies and the absence of lipid lamellae in smsk epidermis. Unexpectedly, mutant stratum corneum remained intact when subjected to harsh chemical dissociation procedures. Moreover, both KALLIKREIN 5 and -7 were drastically decreased, with retention of desmoplakin in mutant SC. In cultured wild type keratinocytes, both KALLIKREIN 5 and -7 colocalized with ceramide metabolites following calcium-induced differentiation. Reducing the intracellular levels of glucosylceramide with a glucosylceramide synthase inhibitor resulted in decreased secretion of KALLIKREIN proteases by wild type keratinocytes, but not by smsk mutant keratinocytes. Together, these findings suggest an essential role for ABCA12 in transferring not only lipids, which are required for the formation of multilamellar structures in the stratum corneum, but also proteolytic enzymes that are required for normal desquamation. Smsk mutant mice recapitulate many of the pathological features of HI and can be used to explore novel topical therapies against a potentially lethal and debilitating neonatal disease.

Two dimensional finite element modelling for dynamic water diffusion through stratum corneum.

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Xiao, Perry; Imhof, Robert E

2012-10-01

Solvents penetration through in vivo human stratum corneum (SC) has always been an interesting research area for trans-dermal drug delivery studies, and the importance of intercellular routes (diffuse in between corneocytes) and transcellular routes (diffuse through corneocytes) during diffusion is often debatable. In this paper, we have developed a two dimensional finite element model to simulate the dynamic water diffusion through the SC. It is based on the brick-and-mortar model, with brick represents corneocytes and mortar represents lipids, respectively. It simulates the dynamic water diffusion process through the SC from pre-defined initial conditions and boundary conditions. Although the simulation is based on water diffusions, the principles can also be applied to the diffusions of other topical applied substances. The simulation results show that both intercellular routes and transcellular routes are important for water diffusion. Although intercellular routes have higher flux rates, most of the water still diffuse through transcellular routes because of the high cross area ratio of corneocytes and lipids. The diffusion water flux, or trans-epidermal water loss (TEWL), is reversely proportional to corneocyte size, i.e. the larger the corneocyte size, the lower the TEWL, and vice versa. There is also an effect of the SC thickness, external air conditions and diffusion coefficients on the water diffusion through SC on the resulting TEWL. Copyright © 2012 Elsevier B.V. All rights reserved.

Molecular dynamics simulations of stratum corneum lipid mixtures: A multiscale perspective.

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Moore, Timothy C; Iacovella, Christopher R; Leonhard, Anne C; Bunge, Annette L; McCabe, Clare

2018-03-29

The lipid matrix of the stratum corneum (SC) layer of skin is essential for human survival; it acts as a barrier to prevent rapid dehydration while keeping potentially hazardous material outside the body. While the composition of the SC lipid matrix is known, the molecular-level details of its organization are difficult to infer experimentally, hindering the discovery of structure-property relationships. To this end, molecular dynamics simulations, which give molecular-level resolution, have begun to play an increasingly important role in understanding these relationships. However, most simulation studies of SC lipids have focused on preassembled bilayer configurations, which, owing to the slow dynamics of the lipids, may influence the final structure and hence the calculated properties. Self-assembled structures would avoid this dependence on the initial configuration, however, the size and length scales involved make self-assembly impractical to study with atomistic models. Here, we report on the development of coarse-grained models of SC lipids designed to study self-assembly. Building on previous work, we present the interactions between the headgroups of ceramide and free fatty acid developed using the multistate iterative Boltzmann inversion method. Validation of the new interactions is performed with simulations of preassembled bilayers and good agreement between the atomistic and coarse-grained models is found for structural properties. The self-assembly of mixtures of ceramide and free fatty acid is investigated and both bilayer and multilayer structures are found to form. This work therefore represents a necessary step in studying SC lipid systems on multiple time and length scales. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of detergents on the physico-chemical properties of skin stratum corneum: A two-photon excitation fluorescence microscopy study

DEFF Research Database (Denmark)

Bloksgaard, Maria; Brewer, Jonathan R.; Pashkovski, Eugene

2014-01-01

OBJECTIVE: Understanding the structural and dynamical features of skin is critical for advancing innovation in personal care and drug discovery. Synthetic detergent mixtures used in commercially available body wash products are thought to be less aggressive towards the skin barrier when compared...... to conventional detergents. The aim of this work is to comparatively characterize the effect of a mild synthetic cleanser mixture (SCM) and sodium dodecyl sulphate (SDS) on the hydration state of the intercellular lipid matrix and on proton activity of excised skin stratum corneum (SC). METHOD: Experiments were...... performed using two-photon excitation fluorescence microscopy. Fluorescent images of fluorescence reporters sensitive to proton activity and hydration of SC were obtained in excised skin and examined in presence and absence of SCM and SDS detergents. RESULTS: Hydration of the intercellular lipid matrix...

[Effects of Frankincense and Myrrh essential oil on transdermal absorption of ferulic acid in Chuanxiong].

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Guan, Yong-Mei; Tao, Ling; Zhu, Xiao-Fang; Zang, Zhen-Zhong; Jin, Chen; Chen, Li-Hua

2017-09-01

The aim of this paper was to explore the effects of Frankincense and Myrrh essential oil on transdermal absorption, and investigate the mechanism of permeation on the microstructure and molecular structure of stratum corneum. Through the determination of stratum corneum/medium partition coefficient of ferulicacid in Chuanxiong influenced by Frankincense and Myrrh essential oil, the effects of volatile oil of frankincense and Myrrh on the the microscopic and molecular structure of stratum corneum were explored by observation of skin stratum corneum structure under scanning electron microscopy, and investigation of frankincense and myrrh essential oil effects on the molecular structure of keratin and lipids in stratum corneum under Fourier transform infrared spectroscopy. The results showed that the oil could enhance the distribution of ferulic acid in the stratum corneum and medium, and to a certain extent damaged the imbricate structure of stratum corneum which was originally regularly, neatly, and closely arranged; some epidermal scales turned upward, with local peeling phenomenon. In addition, frankincense and myrrh essential oil caused the relative displacement of CH2 stretching vibration peak of stratum corneum lipids and amide stretching vibration peak of stratum corneum keratin, indicating that frankincense and myrrh essential oil may change the conformation of lipid and keratin in the stratum corneum, increase the bilayer liquidity of the stratum corneum lipid, and change the orderly and compact structure to increase the skin permeability and reduce the effect of barrier function. It can be concluded that Frankincense and Myrrh essential oil can promote the permeation effect by increasing the distribution of drugs in the stratum corneum and changing the structure of the stratum corneum. Copyright© by the Chinese Pharmaceutical Association.

Skin hydration: interplay between molecular dynamics, structure and water uptake in the stratum corneum.

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Mojumdar, Enamul Haque; Pham, Quoc Dat; Topgaard, Daniel; Sparr, Emma

2017-11-16

Hydration is a key aspect of the skin that influences its physical and mechanical properties. Here, we investigate the interplay between molecular and macroscopic properties of the outer skin layer - the stratum corneum (SC) and how this varies with hydration. It is shown that hydration leads to changes in the molecular arrangement of the peptides in the keratin filaments as well as dynamics of C-H bond reorientation of amino acids in the protruding terminals of keratin protein within the SC. The changes in molecular structure and dynamics occur at a threshold hydration corresponding to ca. 85% relative humidity (RH). The abrupt changes in SC molecular properties coincide with changes in SC macroscopic swelling properties as well as mechanical properties in the SC. The flexible terminals at the solid keratin filaments can be compared to flexible polymer brushes in colloidal systems, creating long-range repulsion and extensive swelling in water. We further show that the addition of urea to the SC at reduced RH leads to similar molecular and macroscopic responses as the increase in RH for SC without urea. The findings provide new molecular insights to deepen the understanding of how intermediate filament organization responds to changes in the surrounding environment.

Stratum corneum molecular mobility in the presence of natural moisturizers.

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Björklund, Sebastian; Andersson, Jenny Marie; Pham, Quoc Dat; Nowacka, Agnieszka; Topgaard, Daniel; Sparr, Emma

2014-07-07

The outermost layer of the skin, the stratum corneum (SC), is a lipid-protein membrane that experiences considerable osmotic stress from a dry and cold climate. The natural moisturizing factor (NMF) comprises small and polar substances, which like osmolytes can protect living systems from osmotic stress. NMF is commonly claimed to increase the water content in the SC and thereby protect the skin from dryness. In this work we challenge this proposed mechanism, and explore the influence of NMF on the lipid and protein components in the SC. We employ natural-abundance (13)C solid-state NMR methods to investigate how the SC molecular components are influenced by urea, glycerol, pyrrolidone carboxylic acid (PCA), and urocanic acid (UCA), all of which are naturally present in the SC as NMF compounds. Experiments are performed with intact SC, isolated corneocytes and model lipids. The combination of NMR experiments provides molecularly resolved qualitative information on the dynamics of different SC lipid and protein components. We obtain completely novel molecular information on the interaction of these NMF compounds with the SC lipids and proteins. We show that urea and glycerol, which are also common ingredients in skin care products, increase the molecular mobility of both SC lipids and proteins at moderate relative humidity where the SC components are considerably more rigid in the absence of these compounds. This effect cannot be attributed to increased SC water content. PCA has no detectable effect on SC molecular mobility under the conditions investigated. It is finally shown that the more apolar compound, UCA, specifically influences the mobility of the SC lipid regions. The present results show that the NMF components act to retain the fluidity of the SC molecular components under dehydrating conditions in such a way that the SC properties remain largely unchanged as compared to more hydrated SC. These findings provide a new molecular insight into how small

Lipid composition of the stratum corneum and cutaneous water loss in birds along an aridity gradient.

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Champagne, Alex M; Muñoz-Garcia, Agustí; Shtayyeh, Tamer; Tieleman, B Irene; Hegemann, Arne; Clement, Michelle E; Williams, Joseph B

2012-12-15

Intercellular and covalently bound lipids within the stratum corneum (SC), the outermost layer of the epidermis, are the primary barrier to cutaneous water loss (CWL) in birds. We compared CWL and intercellular SC lipid composition in 20 species of birds from desert and mesic environments. Furthermore, we compared covalently bound lipids with CWL and intercellular lipids in the lark family (Alaudidae). We found that CWL increases in birds from more mesic environments, and this increase was related to changes in intercellular SC lipid composition. The most consistent pattern that emerged was a decrease in the relative amount of cerebrosides as CWL increased, a pattern that is counterintuitive based on studies of mammals with Gaucher disease. Although covalently bound lipids in larks did not correlate with CWL, we found that covalently bound cerebrosides correlated positively with intercellular cerebrosides and intercellular cholesterol ester, and intercellular cerebrosides correlated positively with covalently bound free fatty acids. Our results led us to propose a new model for the organization of lipids in the avian SC, in which the sugar moieties of cerebrosides lie outside of intercellular lipid layers, where they may interdigitate with adjacent intercellular cerebrosides or with covalently bound cerebrosides.

Relative uptake of minoxidil into appendages and stratum corneum and permeation through human skin in vitro.

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Grice, Jeffrey E; Ciotti, Susan; Weiner, Norman; Lockwood, Peter; Cross, Sheree E; Roberts, Michael S

2010-02-01

We examined uptake of the model therapeutic agent, minoxidil, into appendages, stratum corneum (SC), and through human skin, under the influence of different vehicles. Quantitative estimation of therapeutic drug deposition into all three areas has not previously been reported. Finite doses of minoxidil (2%, w/v) in formulations containing varying amounts of ethanol, propylene glycol (PG), and water (60:20:20, 80:20:0, and 0:80:20 by volume, respectively) were used. Minoxidil in SC (by tape stripping), appendages (by cyanoacrylate casting), and receptor fluid was determined by liquid scintillation counting. At early times (30 min, 2 h), ethanol-containing formulations (60:20:20 and 80:20:0) caused significantly greater minoxidil retention in SC and appendages, compared to the formulation lacking ethanol (0:80:20). A significant increase in minoxidil receptor penetration occurred with the PG-rich 0:80:20 formulation after 12 h. We showed that deposition of minoxidil into appendages, SC, and skin penetration into receptor fluid were similar in magnitude. Transport by the appendageal route is likely to be a key determinant of hair growth promotion by minoxidil. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

The Human Stratum Corneum Prevents Small Gold Nanoparticle Penetration and Their Potential Toxic Metabolic Consequences

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David C. Liu

2012-01-01

Full Text Available Nanoparticles are being used in multiple applications, ranging from biomedical and skin care products (e.g., sunscreen through to industrial manufacturing processes (e.g., water purification. The increase in exposure has led to multiple reports on nanoparticle penetration and toxicity. However, the correlation between nanoparticle size and its penetration without physical/chemical enhancers through the skin is poorly understood—with studies instead focusing primarily on skin penetration under disrupted conditions. In this paper, we investigate the penetration and metabolic effects of 10 nm, 30 nm, and 60 nm gold nanoparticles within viable excised human skin after 24-hour exposure using multiphoton tomograph-fluorescence lifetime imaging microscopy. After 24 hour treatment with the 10, 30, and 60 nm gold nanoparticles, there was no significant penetration detected below the stratum corneum. Furthermore, there were no changes in metabolic output (total NAD(PH in the viable epidermis posttreatment correlating with lack of penetration of nanoparticles. These results are significant for estimating topical nanoparticle exposure in humans where other model systems may overestimate the exposure of nanoparticles to the viable epidermis. Our data shows that viable human skin resists permeation of small nanoparticles in a size range that has been reported to penetrate deeply in other skin models.

Ethnic differences in stratum corneum functions between Chinese and Thai infants residing in Bangkok, Thailand.

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Fujimura, Tsutomu; Miyauchi, Yuki; Shima, Kyoko; Hotta, Mitsuyuki; Tsujimura, Hisashi; Kitahara, Takashi; Takema, Yoshinori; Palungwachira, Pakhawadee; Laohathai, Diane; Chanthothai, Jetchawa; Nararatwanchai, Thamthiwat

2018-01-01

Ethnic and racial differences in infant skin have not been well characterized. The purpose of this study was to establish whether there are ethnic differences and similarities in the stratum corneum (SC) functions of Thai and Chinese infants. Healthy infants 6 to 24 months of age (N = 60; 30 Thai, 30 Chinese) who resided in Bangkok, Thailand, were enrolled. Transepidermal water loss (TEWL) and SC hydration (capacitance) on the thigh, buttock, and upper arm were measured. Ceramide content was determined in the SC on the upper arm. SC hydration was not remarkably different between the two ethnicities at any site measured, but TEWL was significantly higher in Chinese infants than in Thai infants at all sites. Hydration of the SC was not significantly correlated with age in either ethnicity. TEWL had significant but weak correlations with age on the thigh and upper arm in Thai infants. Ceramide content was significantly higher in Chinese SC than in Thai SC. No relationship between ceramide content and TEWL or hydration was observed in either ethnicity. The significant differences in TEWL and ceramide contents between Chinese and Thai infant skin could prove useful in designing skin care and diapering products that are best suited for each ethnicity. © 2017 Wiley Periodicals, Inc.

Optimization of transdermal delivery using magainin pore-forming peptide

OpenAIRE

Kim, Yeu-Chun; Ludovice, Peter J.; Prausnitz, Mark R.

2008-01-01

The skin's outer layer of stratum corneum, which is a thin tissue containing multilamellar lipid bilayers, is the main barrier to drug delivery to the skin. To increase skin permeability, our previous work has shown large enhancement of transdermal permeation using a pore-forming peptide, magainin, which was formulated with N-lauroyl sarcosine (NLS) in 50% ethanol-in-PBS. Mechanistic analysis suggested that magainin and NLS can increase skin permeability by disrupting stratum corneum lipid st...

Effects of UVA (320-400 nm) on the barrier characteristics of the skin

International Nuclear Information System (INIS)

McAuliffe, D.J.; Blank, I.H.

1991-01-01

The stratum corneum serves as the major barrier to the entrance of most molecules into the skin. In the studies presented here, the effects of UVA radiation (320-400 nm) on the barrier capacity of human stratum corneum were examined. Penetration of a homologous series of primary alcohols through unirradiated (control) and UVA-irradiated (test) human epidermis was determined in vitro. Permeability constants, kp, were calculated. Mean ratios of permeability constants for UVA-irradiated and unirradiated epidermis (mean kp test)/(mean kp control) ranged from 2.3 to 3.0 for methanol and from 2.2 to 2.5 for ethanol. These mean ratios were determined using different pieces of epidermis from the same piece of skin for test and control samples. When kp control and kp test were determined on the same piece of epidermis on successive days, the ratios (kp test/kp control) were similar to the mean ratios determined on different pieces of epidermis. For other primary alcohols, propanol, butanol, hexanol, and heptanol, UVA radiation did not alter their permeability constants significantly. Partition coefficients, Km, were determined for ethanol and heptanol using UVA-irradiated and unirradiated stratum corneum. For ethanol, irradiation resulted in a 1.5 to 2.6 times increase in Km. For heptanol, irradiation caused no change in Km. These results demonstrate that the barrier capacity of stratum corneum for small, polar, primary alcohols is diminished (permeability increases) and for higher molecular weight less polar alcohols, is unaffected by small doses of UVA radiation. This increased permeability of small polar alcohols through human skin may be due to enhanced partitioning into UVA-irradiated stratum corneum, which was not apparent for a higher molecular weight less polar alcohol

The use of D-optimal mixture design in optimising okara soap formulation for stratum corneum application.

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Borhan, Farrah Payyadhah; Abd Gani, Siti Salwa; Shamsuddin, Rosnah

2014-01-01

Okara, soybean waste from tofu and soymilk production, was utilised as a natural antioxidant in soap formulation for stratum corneum application. D-optimal mixture design was employed to investigate the influence of the main compositions of okara soap containing different fatty acid and oils (virgin coconut oil A (24-28% w/w), olive oil B (15-20% w/w), palm oil C (6-10% w/w), castor oil D (15-20% w/w), cocoa butter E (6-10% w/w), and okara F (2-7% w/w)) by saponification process on the response hardness of the soap. The experimental data were utilized to carry out analysis of variance (ANOVA) and to develop a polynomial regression model for okara soap hardness in terms of the six design factors considered in this study. Results revealed that the best mixture was the formulation that included 26.537% A, 19.999% B, 9.998% C, 16.241% D, 7.633% E, and 7.000% F. The results proved that the difference in the level of fatty acid and oils in the formulation significantly affects the hardness of soap. Depending on the desirable level of those six variables, creation of okara based soap with desirable properties better than those of commercial ones is possible.

The Use of D-Optimal Mixture Design in Optimising Okara Soap Formulation for Stratum Corneum Application

Science.gov (United States)

Borhan, Farrah Payyadhah; Abd Gani, Siti Salwa; Shamsuddin, Rosnah

2014-01-01

Okara, soybean waste from tofu and soymilk production, was utilised as a natural antioxidant in soap formulation for stratum corneum application. D-optimal mixture design was employed to investigate the influence of the main compositions of okara soap containing different fatty acid and oils (virgin coconut oil A (24–28% w/w), olive oil B (15–20% w/w), palm oil C (6–10% w/w), castor oil D (15–20% w/w), cocoa butter E (6–10% w/w), and okara F (2–7% w/w)) by saponification process on the response hardness of the soap. The experimental data were utilized to carry out analysis of variance (ANOVA) and to develop a polynomial regression model for okara soap hardness in terms of the six design factors considered in this study. Results revealed that the best mixture was the formulation that included 26.537% A, 19.999% B, 9.998% C, 16.241% D, 7.633% E, and 7.000% F. The results proved that the difference in the level of fatty acid and oils in the formulation significantly affects the hardness of soap. Depending on the desirable level of those six variables, creation of okara based soap with desirable properties better than those of commercial ones is possible. PMID:25548777

The Use of D-Optimal Mixture Design in Optimising Okara Soap Formulation for Stratum Corneum Application

Directory of Open Access Journals (Sweden)

Farrah Payyadhah Borhan

2014-01-01

Full Text Available Okara, soybean waste from tofu and soymilk production, was utilised as a natural antioxidant in soap formulation for stratum corneum application. D-optimal mixture design was employed to investigate the influence of the main compositions of okara soap containing different fatty acid and oils (virgin coconut oil A (24–28% w/w, olive oil B (15–20% w/w, palm oil C (6–10% w/w, castor oil D (15–20% w/w, cocoa butter E (6–10% w/w, and okara F (2–7% w/w by saponification process on the response hardness of the soap. The experimental data were utilized to carry out analysis of variance (ANOVA and to develop a polynomial regression model for okara soap hardness in terms of the six design factors considered in this study. Results revealed that the best mixture was the formulation that included 26.537% A, 19.999% B, 9.998% C, 16.241% D, 7.633% E, and 7.000% F. The results proved that the difference in the level of fatty acid and oils in the formulation significantly affects the hardness of soap. Depending on the desirable level of those six variables, creation of okara based soap with desirable properties better than those of commercial ones is possible.

Further investigations on the role of ascorbic acid in stratum corneum lipid models after UV exposure.

Science.gov (United States)

Trommer, Hagen; Böttcher, Rolf; Huschka, Christoph; Wohlrab, Wolfgang; Neubert, Reinhard H H

2005-08-01

This study is the continuation of our research into vitamin C and its possible effects on human skin after topical administration. The effects of ascorbic acid, iron ions and UV irradiation on stratum corneum lipid models were investigated. The lipid models used were: a simple system (linolenic acid dispersion), a complex system (liposomes consisting of dipalmitoylphosphatidylcholine, cholesterol and linolenic acid) and complex systems with additionally incorporated ceramides (types III and IV). The lipid peroxidation was quantified by the thiobarbituric acid assay. A human adult low-calcium high-temperature (HaCaT) keratinocytes cell culture was used as a second in-vitro model. The amount of intracellular peroxides was determined by measuring the fluorescence intensity using the dihydrorhodamine 123 assay. Electron paramagnetic resonance spectroscopy was used to study the influence of ascorbic acid and iron ions on the signal intensity of 5-doxylstearic acid during UV exposure. Ascorbic acid showed prooxidative properties in the thiobarbituric acid assay whereas cell protection was measured in the HaCaT keratinocytes experiments. Electron paramagnetic resonance investigations revealed different extents of free radical production generated by iron ions, ascorbic acid and UV irradiation. In evaluating the results from this study new aspects of the mechanism of lipid damage caused by these three factors were suggested, transcending the simple redox behaviour of ascorbic acid.

Microautoradiography of /sup 14/C-salicylic acid in the skin of guinea-pig

Energy Technology Data Exchange (ETDEWEB)

Washitake, M; Ozawa, Y; Anmo, T; Tanaka, I [Taisho Pharmaceutical Co. Ltd., Tokyo (Japan). Research Lab.

1974-07-01

The concentration of salicylic acid in guinea-pig skin was examined by microautoradiography. The retention of salicylic acid in the stratum corneum was observed. It was considered that the rate of transfer of the drug into the stratum corneum was small and that the stratum corneum became the barrier for permeability of the skin. The distribution of salicylic acid in other parts of the skin was uniform and no retention of the drug in any special parts was observed. The plasma level showed less percutaneous absorption of the drug when it was applied as liquid paraffin solution than when it was applied as an aqueous solution. The amount of salicylic acid absorbed from damaged skin was extremely large and, in this case, disappearance of the drug from the skin was fast.

Microautoradiography of 14C-salicylic acid in the skin of guinea-pig

International Nuclear Information System (INIS)

Washitake, Mitsunori; Ozawa, Yasuo; Anmo, Toshio; Tanaka, Ichiro

1974-01-01

The concentration of salicylic acid in guinea-pig skin was examined by microautoradiography. The retention of salicylic acid in the stratum corneum was observed. It was considered that the rate of transfer of the drug into the stratum corneum was small and that the stratum corneum became the barrier for permeability of the skin. The distribution of salicylic acid in other parts of the skin was uniform and no retention of the drug in any special parts was observed. The plasma level showed less percutaneous absorption of the drug when it was applied as liquid paraffin solution than when it was applied as an aqueous solution. The amount of salicylic acid absorbed from damaged skin was extremely large and, in this case, disappearance of the drug from the skin was fast. (author)

Determination of the influence of C24 D/(2R)- and L/(2S)-isomers of the CER[AP] on the lamellar structure of stratum corneum model systems using neutron diffraction.

Science.gov (United States)

Schmitt, Thomas; Lange, Stefan; Sonnenberger, Stefan; Dobner, Bodo; Demé, Bruno; Neubert, Reinhard H H; Gooris, Gert; Bouwstra, Joke A

2017-12-01

This study was able to investigate the different influence of the d- and l-ceramide [AP] on the lamellar as well as molecular nanostructure of stratum corneum simulating lipid model mixtures. In this case, neutron diffraction together with specifically deuterated ceramide was used as an effective tool to investigate the lamellar and the molecular nanostructure of the mixtures. It could clearly be demonstrated, that both isomers show distinctly different characteristics, even though the variation between both is only a single differently arranged OH-group. The l-ceramide [AP] promotes a crystalline like phase behaviour even if mixed with ceramide [NP], cholesterol and free fatty acids. The d-ceramide [AP] only shows crystalline-like features if mixed only with cholesterol and free fatty acids but adopts a native-like behaviour if additionally mixed with ceramide [NP]. It furthermore demonstrates that the l-ceramide [AP] should not be used for any applications concerning ceramide substitution. It could however possibly serve its own purpose, if this crystalline like behaviour has some kind of positive influence on the SC or can be utilized for any practical applications. The results obtained in this study demonstrate that the diastereomers of ceramide [AP] are an attractive target for further research because their influence on the lamellar as well as the nanostructure is exceptionally strong. Additionally, the results furthermore show a very strong influence on hydration of the model membrane. With these properties, the d-ceramide [AP] could be effectively used to simulate native like behaviour even in very simple mixtures and could also have a strong impact on the native stratum corneum as well as high relevance for dermal ceramide substitution. The unnatural l-ceramide [AP] on the other hand should be investigated further, to assess its applicability. Copyright © 2017 Elsevier B.V. All rights reserved.

Heavy Cigarette Smokers in a Chinese Population Display a Compromised Permeability Barrier

Science.gov (United States)

Xin, Shujun; Ye, Li; Lv, Chengzhi; Elias, Peter M.

2016-01-01

Cigarette smoking is associated with various cutaneous disorders with defective permeability. Yet, whether cigarette smoking influences epidermal permeability barrier function is largely unknown. Here, we measured skin biophysical properties, including permeability barrier homeostasis, stratum corneum (SC) integrity, SC hydration, skin surface pH, and skin melanin/erythema index, in cigarette smokers. A total of 99 male volunteers were enrolled in this study. Smokers were categorized as light-to-moderate (hydration and skin melanin/erythema index on the dorsal hand, forehead, and cheek. Basal transepidermal water loss (TEWL) and barrier recovery rates were assessed on the forearm. A Skin-pH-Meter pH900 was used to measure skin surface pH. Our results showed that heavy cigarette smokers exhibited delayed barrier recovery after acute abrogation (1.02% ± 13.06 versus 16.48% ± 6.07), and barrier recovery rates correlated negatively with the number of daily cigarettes consumption (p = 0.0087). Changes in biophysical parameters in cigarette smokers varied with body sites. In conclusion, heavy cigarette smokers display compromised permeability barrier homeostasis, which could contribute, in part, to the increased prevalence of certain cutaneous disorders characterized by defective permeability. Thus, improving epidermal permeability barrier should be considered for heavy cigarette smokers. PMID:27437403

Plastic occlusion stress test as a model to investigate the effects of skin delipidization on the stratum corneum water holding capacity in vivo.

Science.gov (United States)

Berardesca, E; Herbst, R; Maibach, H

1993-01-01

The purpose of the study was to develop an in vivo model to study the effects of lipid removal on skin barrier. 16 subjects (age 41 +/- 8) were delipidized in vivo on the volar forearm using respectively ether/acetone (EA; 1:1) and chloroform/methanol (CM; 2:1). A third site served as control. Water holding capacity (WHC) was measured according to the plastic occlusion stress test (POST) procedure: the water desorption curve after removal of the occlusion was recorded in terms of skin surface water loss (SSWL) using an evaporimeter for 30 min. In the central part of the evaporation curve (bound water) the CM-treated site is significantly different from control and EA-treated sites (p rate of water from SC are higher in the CM-treated site (p evaporation of free water. We conclude that polar lipids have a key role in modulating barrier function and WHC of the stratum corneum. The POST can represent a useful in vivo model to study the effects of lipid extraction on skin function.

Cutaneous water loss and the development of the stratum corneum of nestling house sparrows (Passer domesticus) from desert and mesic environments.

Science.gov (United States)

Muñoz-Garcia, Agustí; Williams, Joseph B

2011-01-01

Evaporation through the skin contributes to more than half of the total water loss in birds. Therefore, we expect the regulation of cutaneous water loss (CWL) to be crucial for birds, especially those that live in deserts, to maintain a normal state of hydration. Previous studies in adult birds showed that modifications of the lipid composition of the stratum corneum (SC), the outer layer of the epidermis, were associated with changes in rates of CWL. However, few studies have examined the ontogeny of CWL and the lipids of the SC in nestling birds. In this study, we measured CWL and the lipid composition of the SC during development of nestlings from two populations of house sparrows, one from the deserts of Saudi Arabia and the other from mesic Ohio. We found that desert and mesic nestlings followed different developmental trajectories for CWL. Desert nestlings seemed to make a more frugal use of water than did mesic nestlings. To regulate CWL, nestlings appeared to modify the lipid composition of the SC during ontogeny. Our results also suggest a tighter regulation of CWL in desert nestlings, presumably as a result of the stronger selection pressures to which nestlings are exposed in deserts.

Stratum corneum profiles of inflammatory mediators in patch test reactions to common contact allergens and sodium lauryl sulfate.

Science.gov (United States)

Koppes, S A; Ljubojevic Hadzavdic, S; Jakasa, I; Franceschi, N; Jurakić Tončić, R; Marinović, B; Brans, R; Gibbs, S; Frings-Dresen, M H W; Rustemeyer, T; Kezic, S

2017-06-01

Recent studies have demonstrated allergen-specific differences in the gene expression of inflammatory mediators in patch tested skin. To determine levels of various inflammatory mediators in the stratum corneum (SC) after patch testing with common contact allergens and the skin irritant sodium lauryl sulfate (SLS). In total, 27 individuals who had previously patch tested positive to nickel, chromium, methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) or para-phenylenediamine were retested and then patch tested with SLS and petrolatum, with petrolatum serving as the patch test control. At 72 h, the test sites were clinically graded and the SC samples collected on adhesive tape. The levels of 18 of the 32 quantified mediators differed significantly from that of the control patches for at least one of the tested substances. SLS and MCI/MI induced the largest number of immunomediators. Interleukin (IL)-16 levels were significantly higher in patch test reactions in all allergens than they were in the controls, while no significant difference was detected for SLS. Furthermore, a strong negative correlation was found between strength of patch test reaction and IL-1α levels. Cytokine profiles in the SC of patch tested skin did not show a distinct allergen-specific pattern. However, MCI/MI induced a larger and wider immune response than the other allergens, perhaps due to its potency as an irritant. The levels of IL-16 were significantly increased in patch test reactions to allergens but not to SLS; thus, they may help clinicians to differentiate between allergic contact dermatitis and irritant contact dermatitis. © 2016 British Association of Dermatologists.

Isolated human/animal stratum corneum as a partial model for 15 steps in percutaneous absorption: emphasizing decontamination, Part I.

Science.gov (United States)

Hui, Xiaoying; Lamel, Sonia; Qiao, Peter; Maibach, Howard I

2013-03-01

Since the advent of World War II, governments and laboratories have made a concerted effort to improve prophylactic and therapeutic interventions counteracting cutaneously directed chemical warfare agents (CWA), and by inference, common industrial and consumer dermatotoxicants. In vitro percutaneous penetration assays, first utilized by Tregear in the 1940s and presently in various modifications, have been fundamental to this effort. Percutaneous penetration, often considered a simple one-step diffusion process, consists of at least 15 steps. The first part of this review covers the initial steps related to absorption and excretion kinetics, vehicle characteristics, and tissue disposition. Importantly, the partitioning behavior and stratum corneum (SC) diffusion by a wide physicochemical array of compounds shows that many compounds have similar diffusion coefficients determining their percutaneous absorption in vivo. After accounting for anatomical SC variation, the penetration flux value of a substance depends mainly on its SC/vehicle partition coefficient. Additionally, the SC acts as a 'reservoir' for topically applied molecules and application of tape stripping has been found to quantify the chemical remaining in the SC which can predict total molecular penetration in vivo. Decontamination is of particular concern and even expediting standard washing procedures after dermal chemical exposure often fails to remove chemicals. This overview summarizes knowledge of percutaneous penetration extending insights into the complexities of penetration, decontamination and potential newer assays that may be of practical importance. Copyright © 2012 John Wiley & Sons, Ltd.

Evaluation of skin surface hydration state and barrier function of stratum corneum of dorsa of hands and heels treated with PROTECT X2 skin protective cream.

Science.gov (United States)

Kubota, Takahiro

2012-06-01

Skin roughness is a term commonly used in Japan to describe a poor skin condition related to a rough and dry skin surface that develops as a result of various damaging effects from the environment or skin inflammation. Recovery from skin roughness requires skin care for a long period, thus it is important to prevent development of such skin changes. PROTECT X2 contains agents used for a protective covering of the skin from frequent hand washing or use of alcohol-based disinfectants. These unique components are also thought to be effective to treat skin roughness of the dorsa of the hands and heels. In the present study, we evaluated the effectiveness of PROTECT X2 to increase skin surface hydration state, as well as enhance the barrier function of the stratum corneum of the dorsa of the hands and heels in elderly individuals. A total of 8 elderly subjects and their caretakers without any skin diseases participated in the study. They applied PROTECT X2 by themselves to the dorsum area of 1 hand and heel 3 to 5 times daily for 1 month, while the opposite sides were left untreated. We measured stratum corneum (SC) hydration and transepidermal water loss (TEWL) before beginning treatment, then 1 week and 1 month after the start of treatment to compare between the treated and untreated skin. SC hydration state after applications of PROTECT X2 was 1.5- to 3.0-fold higher than that of the untreated skin in the dorsa of both hands and heels, indicating that the moisturizing ingredients accompanied by water were replenished in those areas where the cream was applied. Also, TEWL in the dorsum of the hands was 17.0-27.9% lower on the treated side, indicating improvement in SC barrier function. On the basis of these findings, we concluded that PROTECT X2 enhances water-holding in the SC and aids the barrier function of the skin in the dorsum of the hands. In addition, we consider that this formulation is useful for not only protecting the hands from the effects of such agents

Changes in hydration of the stratum corneum are the most suitable indicator to evaluate the irritation of surfactants on the skin.

Science.gov (United States)

Fujimura, T; Shimotoyodome, Y; Nishijima, T; Sugata, K; Taguchi, H; Moriwaki, S

2017-02-01

Irritancy levels of surfactants on human skin have not been clarified completely. The relationships between skin damage and changes of skin properties caused by various surfactants were investigated using non-invasive measurements. Aqueous solutions of seven kinds of anionic, non-ionic, and amphoteric surfactants were exposed to the inside of forearm skin of 20 human subjects in two separate studies using the cup method. Hydration of the stratum corneum (SC), transepidermal water loss (TEWL), pH, skin surface roughness, and contents of the SC were measured before and after one exposure and after five and nine consecutive exposures to various surfactants. The discontinuation ratio of subjects for testing in each surfactant was determined by skin irritation symptoms and was defined as the degree of skin damage. Significant changes were observed only in hydration, TEWL, and natural moisturizing factors (NMF) content in the SC following surfactant exposure. A significant correlation was observed between the discontinuation ratio of each surfactant and the changes of hydration, TEWL, and NMF. Especially, the change of SC hydration showed an excellent correlation with the discontinuation ratio both for single (r = 0.942, P hydration of the SC is equivalent to the skin damage caused by surfactants, and therefore is the most suitable indicator to evaluate the irritation of surfactants on the skin. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Status of surfactants as penetration enhancers in transdermal drug delivery

Directory of Open Access Journals (Sweden)

Iti Som

2012-01-01

Full Text Available Surfactants are found in many existing therapeutic, cosmetic, and agro-chemical preparations. In recent years, surfactants have been employed to enhance the permeation rates of several drugs via transdermal route. The application of transdermal route to a wider range of drugs is limited due to significant barrier to penetration across the skin which is associated with the outermost stratum corneum layer. Surfactants have effects on the permeability characteristics of several biological membranes including skin. They have the potential to solubilize lipids within the stratum corneum. The penetration of the surfactant molecule into the lipid lamellae of the stratum corneum is strongly dependent on the partitioning behavior and solubility of surfactant. Surfactants ranging from hydrophobic agents such as oleic acid to hydrophilic sodium lauryl sulfate have been tested as permeation enhancer to improve drug delivery. This article reviews the status of surfactants as permeation enhancer in transdermal drug delivery of various drugs.

Effects of atmospheric relative humidity on Stratum Corneum structure at the molecular level: ex vivo Raman spectroscopy analysis.

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Vyumvuhore, Raoul; Tfayli, Ali; Duplan, Hélène; Delalleau, Alexandre; Manfait, Michel; Baillet-Guffroy, Arlette

2013-07-21

Skin hydration plays an important role in the optimal physical properties and physiological functions of the skin. Despite the advancements in the last decade, dry skin remains the most common characteristic of human skin disorders. Thus, it is important to understand the effect of hydration on Stratum Corneum (SC) components. In this respect, our interest consists in correlating the variations of unbound and bound water content in the SC with structural and organizational changes in lipids and proteins using a non-invasive technique: Raman spectroscopy. Raman spectra were acquired on human SC at different relative humidity (RH) levels (4-75%). The content of different types of water, bound and free, was measured using the second derivative and curve fitting of the Raman bands in the range of 3100-3700 cm(-1). Changes in lipidic order were evaluated using νC-C and νC-H. To analyze the effect of RH on the protein structure, we examined in the Amide I region, the Fermi doublet of tyrosine, and the νasymCH3 vibration. The contributions of totally bound water were found not to vary with humidity, while partially bound water varied with three different rates. Unbound water increased greatly when all sites for bound water were saturated. Lipid organization as well as protein deployment was found to be optimal at intermediate RH values (around 60%), which correspond to the maximum of SC water binding capacity. This analysis highlights the relationship between bound water, the SC barrier state and the protein structure and elucidates the optimal conditions. Moreover, our results showed that increased content of unbound water in the SC induces disorder in the structures of lipids and proteins.

Developmental plasticity of cutaneous water loss and lipid composition in stratum corneum of desert and mesic nestling house sparrows.

Science.gov (United States)

Muñoz-Garcia, Agustí; Williams, Joseph B

2008-10-07

Intercellular lipids of the stratum corneum (SC), the outer layer of the epidermis, form a barrier to water vapor diffusion through the skin. Previously, we measured cutaneous water loss (CWL) and lipid composition of the SC of adult house sparrows from two populations, one living in the deserts of Saudi Arabia and another living in mesic Ohio. Adult desert house sparrows had a lower CWL, a lower proportion of free fatty acids, and a higher proportion of ceramides and cerebrosides in the SC compared with mesic sparrows. In this study, we investigated developmental plasticity of CWL and lipid composition of the SC in desert and mesic nestling house sparrows reared in low and high humidity and compared our results with previous work on adults. We measured CWL of nestlings and analyzed the lipid composition of the SC using thin-layer chromatography. We showed that nestling house sparrows from both localities had higher CWL than adults in their natural environment, a result of major modifications of the lipid composition of the SC. The expression of plasticity in CWL seems to be a response to opposed selection pressures, thermoregulation and water conservation, at different life stages, on which regulation of CWL plays a crucial role. Desert nestlings showed a greater degree of plasticity in CWL and lipid composition of the SC than did mesic nestlings, a finding consistent with the idea that organisms exposed to more environmental stress ought to be more plastic than individuals living in more benign environments.

Drug Delivery Through the Skin: Molecular Simulations of Barrier Lipids to Design more Effective Noninvasive Dermal and Transdermal Delivery Systems for Small Molecules Biologics and Cosmetics

Energy Technology Data Exchange (ETDEWEB)

J Torin Huzil; S Sivaloganathan; M Kohandel; M Foldvari

2011-12-31

The delivery of drugs through the skin provides a convenient route of administration that is often preferable to injection because it is noninvasive and can typically be self-administered. These two factors alone result in a significant reduction of medical complications and improvement in patient compliance. Unfortunately, a significant obstacle to dermal and transdermal drug delivery alike is the resilient barrier that the epidermal layers of the skin, primarily the stratum corneum, presents for the diffusion of exogenous chemical agents. Further advancement of transdermal drug delivery requires the development of novel delivery systems that are suitable for modern, macromolecular protein and nucleotide therapeutic agents. Significant effort has already been devoted to obtain a functional understanding of the physical barrier properties imparted by the epidermis, specifically the membrane structures of the stratum corneum. However, structural observations of membrane systems are often hindered by low resolutions, making it difficult to resolve the molecular mechanisms related to interactions between lipids found within the stratum corneum. Several models describing the molecular diffusion of drug molecules through the stratum corneum have now been postulated, where chemical permeation enhancers are thought to disrupt the underlying lipid structure, resulting in enhanced permeability. Recent investigations using biphasic vesicles also suggested a possibility for novel mechanisms involving the formation of complex polymorphic lipid phases. In this review, we discuss the advantages and limitations of permeation-enhancing strategies and how computational simulations, at the atomic scale, coupled with physical observations can provide insight into the mechanisms of diffusion through the stratum corneum.

The long periodicity phase (LPP) controversy part I: The influence of a natural-like ratio of the CER[EOS] analogue [EOS]-br in a CER[NP]/[AP] based stratum corneum modelling system: A neutron diffraction study.

Science.gov (United States)

Schmitt, Thomas; Lange, Stefan; Sonnenberger, Stefan; Dobner, Bodo; Demé, Bruno; Langner, Andreas; Neubert, Reinhard H H

2018-06-18

This study used neutron diffraction to investigate a ceramide-[NP] C24/[AP] C24 /[EOS]-br C30/cholesterol/lignoceric acid (0.6: 0.3: 0.1: 0.7: 1) based stratum corneum modelling system. By adding specifically deuterated ceramides-[NP]-D 3 , [AP]-D 3 , and [EOS]-br-D 3 , detailed information on the lamellar and the nanostructure of the system was obtained. For the short periodicity phase a natural-like lamellar repeat distance of 5.47 ± 0.02 nm was observed, similar to the [NP]/[AP] base system without the [EOS]-br. Unlike in this system the ceramides here were slightly tilted, hinting towards a slightly less natural arrangement. Due to the deuteration it was possible to observe that the long ceramide chains were overlapping in the lamellar mid-plane. This is considered to be an important feature for the natural stratum corneum. Despite the presence of a ceramide [EOS] analogue - able to form a long phase arrangement - no distinct long periodicity phase was formed, despite a slightly higher than natural ω-acyl ceramide ratio of 10 mol%. The deuterated variant of this ceramide determined that the very long ceramide was integrated into the short periodicity phase, spanning multiple layers instead. The - compared to the base system - unchanged repeat distance highlights the stability of this structure. Furthermore, the localisation of the very long ceramide in the short periodicity phase indicates the possibility of a crosslinking effect and thus a multilayer stabilizing role for the ceramide [EOS]. It can be concluded, that additionally to the mere presence of ceramide-[EOS] more complex conditions have to be met in order to form this long phase. This has to be further investigated in the future. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of Exercise-induced Sweating on facial sebum, stratum corneum hydration, and skin surface pH in normal population.

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Wang, Siyu; Zhang, Guirong; Meng, Huimin; Li, Li

2013-02-01

Evidence demonstrated that sweat was an important factor affecting skin physiological properties. We intended to assess the effects of exercise-induced sweating on the sebum, stratum corneum (SC) hydration and skin surface pH of facial skin. 102 subjects (aged 5-60, divided into five groups) were enrolled to be measured by a combination device called 'Derma Unit SSC3' in their frontal and zygomatic regions when they were in a resting state (RS), at the beginning of sweating (BS), during excessive sweating (ES) and an hour after sweating (AS), respectively. Compared to the RS, SC hydration in both regions increased at the BS or during ES, and sebum increased at the BS but lower during ES. Compared to during ES, Sebum increased in AS but lower than RS. Compared to the RS, pH decreased in both regions at the BS in the majority of groups, and increased in frontal region during ES and in zygomatic region in the AS. There was an increase in pH in both regions during ES in the majority of groups compared to the BS, but a decrease in the AS compared to during ES. The study implies that even in summer, after we sweat excessively, lipid products should be applied locally in order to maintain stability of the barrier function of the SC. The study suggests that after a short term(1 h or less) of self adjustment, excessive sweat from moderate exercise will not impair the primary acidic surface pH of the facial skin. Exercise-induced sweating significantly affected the skin physiological properties of facial region. © 2012 John Wiley & Sons A/S.

Stratum Corneum Lipids: Their Role for the Skin Barrier Function in Healthy Subjects and Atopic Dermatitis Patients.

Science.gov (United States)

van Smeden, Jeroen; Bouwstra, Joke A

2016-01-01

Human skin acts as a primary barrier between the body and its environment. Crucial for this skin barrier function is the lipid matrix in the outermost layer of the skin, the stratum corneum (SC). Two of its functions are (1) to prevent excessive water loss through the epidermis and (2) to avoid that compounds from the environment permeate into the viable epidermal and dermal layers and thereby provoke an immune response. The composition of the SC lipid matrix is dominated by three lipid classes: cholesterol, free fatty acids and ceramides. These lipids adopt a highly ordered, 3-dimensional structure of stacked densely packed lipid layers (lipid lamellae): the lateral and lamellar lipid organization. The way in which these lipids are ordered depends on the composition of the lipids. One very common skin disease in which the SC lipid barrier is affected is atopic dermatitis (AD). This review addresses the SC lipid composition and organization in healthy skin, and elaborates on how these parameters are changed in lesional and nonlesional skin of AD patients. Concerning the lipid composition, the changes in the three main lipid classes and the importance of the carbon chain lengths of the lipids are discussed. In addition, this review addresses how these changes in lipid composition induce changes in lipid organization and subsequently correlate with an impaired skin barrier function in both lesional and nonlesional skin of these patients. Furthermore, the effect of filaggrin and mutations in the filaggrin gene on the SC lipid composition is critically discussed. Also, the breakdown products of filaggrin, the natural moisturizing factor molecules and its relation to SC-pH is described. Finally, the paper discusses some major changes in epidermal lipid biosynthesis in patients with AD and other related skin diseases, and how inflammation has a deteriorating effect on the SC lipids and SC biosynthesis. The review ends with perspectives on future studies in relation to

Pig skin structure and transdermal delivery of liposomes: a two photon microscopy study

DEFF Research Database (Denmark)

Carrer, Dolores C.; Vermehren, Charlotte; Bagatolli, Luis

2008-01-01

In this work we have characterized the architecture and physical properties of pig skin epidermis including its permeability to different liposome formulations. Autofluorescence images show that cells in the epidermis, from the basal layer to the stratum corneum, are organized in clusters that ar...

Epidermal hydration levels in rosacea patients improve after minocycline therapy.

LENUS (Irish Health Repository)

Ní Raghallaigh, S

2013-12-06

Patients with rosacea frequently report increased skin sensitivity, with features suggestive of an abnormal stratum corneum (SC) permeability barrier. Sebum, pH and hydration levels influence epidermal homeostasis. The correlation of the change in these parameters with clinically effective treatment has not been previously analysed.

Isolated human and animal stratum corneum as a partial model for the 15 steps of percutaneous absorption: emphasizing decontamination, part II.

Science.gov (United States)

Hui, Xiaoying; Lamel, Sonia; Qiao, Peter; Maibach, Howard I

2013-03-01

Cutaneously directed chemical warfare agents can elicit significant morbidity and mortality. The optimization of prophylactic and therapeutic interventions counteracting these agents is crucial, and the development of decontamination protocols and methodology of post dermal exposure risk assessments would be additionally applicable to common industrial and consumer dermatotoxicants. Percutaneous (PC) penetration is often considered a simple one-step diffusion process but presently consists of at least 15 steps. The systemic exposure to an agent depends on multiple factors and the second part of this review covers absorption and excretion kinetics, wash and rub effects, skin substantivity and transfer, among others. Importantly, the partitioning behavior and diffusion through the stratum corneum (SC) of a wide physicochemical array of compounds shows that many compounds have approximately the same diffusion coefficient which determines their percutaneous absorption in vivo. After accounting for anatomical variation of the SC, the penetration flux value of a substance depends mainly on its SC/vehicle partition coefficient. Additionally, the SC acts as a 'reservoir' for topically applied molecules, and tape stripping methodology can quantify the remaining chemical in the SC which can predict the total molecular penetration in vivo. The determination of ideal decontamination protocols is of utmost importance to reduce morbidity and mortality. However, even expeditious standard washing procedures post dermal chemical exposure often fails to remove chemicals. The second part of this overview continues to review percutaneous penetration extending insights into the complexities of penetration, decontamination and potential newer assays that may be of practical importance. Copyright © 2012 John Wiley & Sons, Ltd.

The effect of the chain length distribution of free fatty acids on the mixing properties of stratum corneum model membranes.

Science.gov (United States)

Oguri, Masashi; Gooris, Gert S; Bito, Kotatsu; Bouwstra, Joke A

2014-07-01

The stratum corneum (SC) plays a fundamental role in the barrier function of the skin. The SC consists of corneocytes embedded in a lipid matrix. The main lipid classes in the lipid matrix are ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs). The aim of this study was to examine the effect of the chain length of FFAs on the thermotropic phase behavior and mixing properties of SC lipids. Fourier transform infrared spectroscopy and Raman imaging spectroscopy were used to study the mixing properties using either protonated or deuterated FFAs. We selected SC model lipid mixtures containing only a single CER, CHOL and either a single FFA or a mixture of FFAs mimicking the FFA SC composition. The single CER consists of a sphingoid base with 18 carbon atoms and an acyl chain with a chain length of 24 carbon atoms. When using lignoceric acid (24 carbon atoms) or a mixture of FFAs, the CER and FFAs participated in mixed crystals, but hydration of the mixtures induced a slight phase separation between CER and FFA. The mixed crystalline structures did not phase separate during storage even up to a time period of 3months. When using palmitic acid (16 carbon atoms), a slight phase separation was observed between FFA and CER. This phase separation was clearly enhanced during hydration and storage. In conclusion, the thermotropic phase behavior and the mixing properties of the SC lipid mixtures were shown to strongly depend on the chain length and chain length distribution of FFAs, while hydration enhanced the phase separation. Copyright © 2014 Elsevier B.V. All rights reserved.

Studies on the relationship between epidermal cell turnover kinetics and permeability of hairless mouse skin

International Nuclear Information System (INIS)

Han, S.R.

1988-01-01

The primary aim of this study was to develop non-invasive, physical means to quantitatively assess the epidermal turnover kinetics and barrier properties of the skin and relate these to the cutaneous irritation which results from ultraviolet light irradiation and mold thermal burns. After systematically injecting radiolabeled glycine, the appearance of radioactivity at the skin's surface indicated the transit time of radiolabeled cells through the skin. By plotting the data as the cumulative specific activity against time and then fitting them with a third order polynomial equation, it is possible to estimate the turnover time of the stratum corneum. The skin turnover was coordinated with non-invasive transepidermal water loss (TEWL) studies determined with an evaporimeter. In vitro diffusion studies of the permeability of hydrocortisone through UVB irradiated and thermally burned skin were also performed. The studies indicated that irritated skin offers a relatively low diffusional resistance to hydrocortisone. Depending on the severity of the trauma, the increases in hydrocortisone's permeability coefficient through irritated skin ranged from a low of about 2 times normal to a high of about 210 times normal. Trauma-induced changes in hydrocortisone permeability parallel changes in TEWL, proving that the barrier deficient state resulting from rapid epidermal turnover is a general phenomenon

Cutaneous water loss and covalently bound lipids of the stratum corneum in nestling house sparrows (Passer domesticus L.) from desert and mesic habitats.

Science.gov (United States)

Clement, Michelle E; Muñoz-Garcia, Agustí; Williams, Joseph B

2012-04-01

Lipids of the stratum corneum (SC), the outer layer of the epidermis of birds and mammals, provide a barrier to water vapor diffusion through the skin. The SC of birds consists of flat dead cells, called corneocytes, and two lipid compartments: an intercellular matrix and a monolayer of covalently bound lipids (CBLs) attached to the outer surface of the corneocytes. We previously found two classes of sphingolipids, ceramides and cerebrosides, covalently bound to corneocytes in the SC of house sparrows (Passer domesticus L.); these lipids were associated with cutaneous water loss (CWL). In this study, we collected adult and nestling house sparrows from Ohio and nestlings from Saudi Arabia, acclimated them to either high or low humidity, and measured their rates of CWL. We also measured CWL for natural populations of nestlings from Ohio and Saudi Arabia, beginning when chicks were 2 days old until they fledged. We then evaluated the composition of the CBLs of the SC of sparrows using thin layer chromatography. We found that adult house sparrows had a greater diversity of CBLs in their SC than previously described. During ontogeny, nestling sparrows increased the amount of CBLs and developed their CBLs differently, depending on their habitat. Acclimating nestlings to different humidity regimes did not alter the ontogeny of the CBLs, suggesting that these lipids represent a fundamental component of SC organization that does not respond to short-term environmental change.

Improving diaper design to address incontinence associated dermatitis

Directory of Open Access Journals (Sweden)

Zöllner Petra

2010-11-01

Full Text Available Abstract Background Incontinence associated dermatitis (IAD is an inflammatory skin disease mainly triggered by prolonged skin contact with urine, feces but also liberal detergent use when cleansing the skin. To minimize the epidermal barrier challenge we optimized the design of adult incontinence briefs. In the fluid absorption area we interposed a special type of acidic, curled-type of cellulose between the top sheet in contact with the skin and the absorption core beneath containing the polyacrylate superabsorber. The intention was to minimize disturbance of the already weak acid mantle of aged skin. We also employed air-permeable side panels to minimize skin occlusion and swelling of the stratum corneum. Methods The surface pH of diapers was measured after repeated wetting with a urine substitute fluid at the level of the top sheet. Occlusive effects and hydration of the stratum corneum were measured after a 4 hour application of different side panel materials by corneometry on human volunteers. Finally, we evaluated skin symptoms in 12 patients with preexisting IAD for 21 days following the institutional switch to the optimized diaper design. Local skin care protocols remained in place unchanged. Results The improved design created a surface pH of 4.6 which was stable even after repeated wetting throughout a 5 hour period. The "standard design" briefs had values of 7.1, which is alkaline compared to the acidic surface of normal skin. Side panels made from non-woven material with an air-permeability of more than 1200 l/m2/s avoided excessive hydration of the stratum corneum when compared to the commonly employed air-impermeable plastic films. Resolution of pre-existing IAD skin lesions was noted in 8 out of 12 patients after the switch to the optimized brief design. Conclusions An improved design of adult-type briefs can create an acidic pH on the surface and breathable side panels avoid over-hydration of the stratum corneum and occlusion

Investigation of a CER[NP]- and [AP]-Based Stratum Corneum Modeling Membrane System: Using Specifically Deuterated CER Together with a Neutron Diffraction Approach.

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Schmitt, Thomas; Lange, Stefan; Dobner, Bodo; Sonnenberger, Stefan; Hauß, Thomas; Neubert, Reinhard H H

2018-01-30

Neutron diffraction was used as a tool to investigate the lamellar as well as molecular nanostructure of ceramide-[NP]/ceramide-[AP]/cholesterol/lignoceric acid model systems with a nativelike 2:1 ratio and a 1:2 ratio to study the influence of the ceramide-[AP]. By using mixtures together with cholesterol and free fatty acids as well as a humidity and temperature chamber while measuring, natural conditions were simulated as closely as possible. Despite its simplicity, the system simulated the native stratum corneum lipid matrix fairly closely, showing a similar lamellar thickness with a repeat distance of 5.45 ± 0.1 nm and a similar arrangement with overlapping long C24 chains. Furthermore, despite the very minor chemical difference between ceramide-[NP] and ceramide-[AP], which is only a single OH group, it was possible to demonstrate substantial differences between the structural influence of the two ceramides. Ceramide-[AP] could be concluded to be arranged in such a way that its C24 chain in both ratios is somehow shorter than that of ceramide-[NP], not overlapping as much with the opposite lamellar leaflet. Furthermore, in the unnatural 1:2 ratio, the higher ceramide-[AP] content causes an increased tilt of the ceramide acyl chains. This leads to even less overlapping within the lamellar midplane, whereas the repeat distance stays the same as for the ceramide-[NP]-rich system. In this nativelike 2:1 ratio, the chains are arranged mostly straight, and the long C24 chains show a broad overlapping region in the lamellar midplane.

The importance of microjet vs shock wave formation in sonophoresis.

Science.gov (United States)

Wolloch, Lior; Kost, Joseph

2010-12-01

Low-frequency ultrasound application has been shown to greatly enhance transdermal drug delivery. Skin exposed to ultrasound is affected in a heterogeneous manner, thus mass transport through the stratum corneum occurs mainly through highly permeable localized transport regions (LTRs). Shock waves and microjets generated during inertial cavitations are responsible for the transdermal permeability enhancement. In this study, we evaluated the effect of these two phenomena using direct and indirect methods, and demonstrated that the contribution of microjets to skin permeability enhancement is significantly higher than shock waves. Copyright © 2010. Published by Elsevier B.V.

From contact angle titration to chemical force microscopy: a new route to assess the pH-dependent character of the stratum corneum.

Science.gov (United States)

Wagner, Matthieu; Mavon, Alain; Haidara, Hamidou; Vallat, Marie-France; Duplan, Hélène; Roucoules, Vincent

2012-02-01

Despite of its complex multicomponent organization and its compact architecture, the Stratum corneum (SC) is not completely impermeable to substances directly applied on the skin surface. A huge number of works have been dedicated to the understanding of the mechanisms involved in substance permeation by exploring deeper layers than the SC itself. Surprisingly, there is a poor interest in studies relating to interactions which may occur in the near-surface region (i.e. approximately 1 nm depth) of the SC. In this work, equilibrium proton-transfer reactions have been used as probes to define in a fundamental point of view the nature of the SC interactions with its environment. Such titration curves are investigated on 'in vitro' SC (isolated SC from abdominal skin tissue) and on 'in vivo' volar forearm (a sebum poor area). The results are discussed in term of work of adhesion and surface pKa values. Because SC can 'reconstruct' under heating, influence of the temperature on titration curves is investigated and the role of the different components is discussed. Different sigmoidal transitions were observed. Two common pKa values (pKa(1) = 4 and pKa(2) = 11.5) were clearly identified in both cases and associated to an acid-base character. By playing with the temperature of 'in vitro' SC, the 'accessibility' of polar functions was increased, thus refining the results by revealing an amphoteric character with an acid-to-base transition at pH 3.5 and two acid transitions at pH = 6.5 and pH = 11.5. Adhesion forces between an Atomic Force Microscopy (AFM) tip and a single isolated corneocyte through buffered liquid media were also investigated to better understand the role of the individual corneocytes. © 2011 The Authors. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Commonly Employed African Neonatal Skin Care Products Compromise Epidermal Function in Mice.

Science.gov (United States)

Man, Mao-Qiang; Sun, Richard; Man, George; Lee, Dale; Hill, Zelee; Elias, Peter M

2016-09-01

Neonatal mortality is much higher in the developing world than in developed countries. Infections are a major cause of neonatal death, particularly in preterm infants, in whom defective epidermal permeability barrier function facilitates transcutaneous pathogen invasion. The objective was to determine whether neonatal skin care products commonly used in Africa benefit or compromise epidermal functions in murine skin. After twice-daily treatment of 6- to 8-week-old hairless mice with each skin care product for 3 days, epidermal permeability barrier function, skin surface pH, stratum corneum hydration, and barrier recovery were measured using a multiprobe adapter system physiology monitor. For products showing some benefits in these initial tests, the epidermal permeability barrier homeostasis was assessed 1 and 5 hours after a single application to acutely disrupted skin. All of the skin care products compromised basal permeability barrier function and barrier repair kinetics. Moreover, after 3 days of treatment, most of the products also reduced stratum corneum hydration while elevating skin surface pH to abnormal levels. Some neonatal skin care products that are widely used in Africa perturb important epidermal functions, including permeability barrier homeostasis in mice. Should these products have similar effects on newborn human skin, they could cause a defective epidermal permeability barrier, which can increase body fluid loss, impair thermoregulation, and contribute to the high rates of neonatal morbidity and mortality seen in Africa. Accordingly, alternative products that enhance permeability barrier function should be identified, particularly for use in preterm infants. © 2016 Wiley Periodicals, Inc.

Comparison of rat epidermal keratinocyte organotypic culture (ROC) with intact human skin

DEFF Research Database (Denmark)

Pappinen, Sari; Hermansson, Martin; Kuntsche, Judith

2008-01-01

study was to compare the stratum corneum lipid content of ROC with the corresponding material from human skin. The lipid composition was determined by thin-layer chromatography (TLC) and mass-spectrometry, and the thermal phase transitions of stratum corneum were studied by differential scanning...... calorimetry (DSC). All major lipid classes of the stratum corneum were present in ROC in a similar ratio as found in human stratum corneum. Compared to human skin, the level of non-hydroxyacid-sphingosine ceramide (NS) was increased in ROC, while alpha-hydroxyacid-phytosphingosine ceramide (AP) and non...... compared to human skin, in agreement with the results from DSC. ROC underwent a lipid lamellar order to disorder transition (T2) at a slightly lower temperature (68 degrees C) than human skin (74 degrees C). These differences in stratum corneum lipid composition and the thermal phase transitions may...

Effects of water activity and low molecular weight humectants on skin permeability and hydration dynamics - a double-blind, randomized and controlled study.

Science.gov (United States)

Albèr, C; Buraczewska-Norin, I; Kocherbitov, V; Saleem, S; Lodén, M; Engblom, J

2014-10-01

The mammalian skin is a barrier that effectively separates the water-rich interior of the body from the normally dryer exterior. Changes in the external conditions, for example ambient humidity, have been shown to affect the skin barrier properties. The prime objective of this study was to evaluate the effect of water activity of a topical formulation on skin hydration and permeability. A second objective was to gain more understanding on how two commonly used humectants, urea and glycerol, affect skin barrier function in vivo. Simple aqueous formulations were applied under occlusion to the volar forearm of healthy volunteers. Following 4-h exposure, skin water loss (by transepidermal water loss measurements), skin hydration (by Corneometry) and skin permeability (by time to vasodilation due to benzyl nicotinate exposure) were monitored. The results demonstrate that a relatively small change in the water activity of a topical formulation is sufficient to induce considerable effects on stratum corneum hydration and permeability to exogenous substances. Exposing the skin to high water activity leads to increased skin hydration and also increased permeability. Furthermore, urea and glycerol promote skin hydration and permeability even at reduced water activity of the applied formulation. These results highlight the importance of considering the water activity in topically applied formulations and the potential benefit of using humectants. The results may impact formulation optimization in how to facilitate skin hydration and to modify skin permeability by temporarily open and close the skin barrier. © 2014 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Genetic Algorithm for Opto-thermal Skin Hydration Depth Profiling Measurements

Science.gov (United States)

Cui, Y.; Xiao, Perry; Imhof, R. E.

2013-09-01

Stratum corneum is the outermost skin layer, and the water content in stratum corneum plays a key role in skin cosmetic properties as well as skin barrier functions. However, to measure the water content, especially the water concentration depth profile, within stratum corneum is very difficult. Opto-thermal emission radiometry, or OTTER, is a promising technique that can be used for such measurements. In this paper, a study on stratum corneum hydration depth profiling by using a genetic algorithm (GA) is presented. The pros and cons of a GA compared against other inverse algorithms such as neural networks, maximum entropy, conjugate gradient, and singular value decomposition will be discussed first. Then, it will be shown how to use existing knowledge to optimize a GA for analyzing the opto-thermal signals. Finally, these latest GA results on hydration depth profiling of stratum corneum under different conditions, as well as on the penetration profiles of externally applied solvents, will be shown.

Skin permeation and antioxidant efficacy of topically applied resveratrol.

Science.gov (United States)

Alonso, Cristina; Martí, M; Barba, C; Carrer, V; Rubio, L; Coderch, L

2017-08-01

The permeation of resveratrol was assessed by in vitro and in vivo experiments 24 h after topical administration. The in vitro profile of resveratrol was assessed by Raman spectroscopy. Human skin permeation was analysed in vivo by the tape stripping method with the progressive removal of the stratum corneum layers using adhesive tape strips. Moreover, the free radical scavenging activity of resveratrol after its topical application was determined using the DPPH assay. The Raman spectra indicated that the topically applied resveratrol penetrates deep into the skin. The results showed high amounts of resveratrol in the different stratum corneum layers close to the surface and a constant lower amount in the upper layers of the viable epidermis. The concentration of resveratrol present in the outermost stratum corneum layers was obtained by tape stripping after in vivo application. The results demonstrated that resveratrol mainly remained in the human stratum corneum layers. After topical application, resveratrol maintained its antiradical activity. The antioxidant efficacy of the compound was higher in the inner layers of the stratum corneum. As these results have demonstrated, topically applied resveratrol reinforces the antioxidant system of the stratum corneum and provides an efficient means of increasing the tissue levels of antioxidants in the human epidermis.

A thermal microjet system with tapered micronozzles fabricated by inclined UV lithography for transdermal drug delivery

Science.gov (United States)

Yoon, Yong-Kyu; Park, Jung-Hwan; Lee, Jeong-Woo; Prausnitz, Mark R.; Allen, Mark G.

2011-02-01

Transdermal drug delivery can be enabled by various methods that increase the permeability of the skin's outer barrier of stratum corneum, including skin exposure to heat and chemical enhancers, such as ethanol. Combining these approaches for the first time, in this study we designed a microdevice consisting of an array of microchambers filled with ethanol that is vaporized using an integrated microheater and ejected through a micronozzle contacting the skin surface. In this way, we hypothesize that the hot ethanol vapor can increase skin permeability upon contacting the skin surface. The tapered micronozzle and the microchamber designed for this application were realized using proximity-mode inclined rotational ultraviolet lithography, which facilitates easy fabrication of complex three-dimensional structures, convenient integration with other functional layers, low fabrication cost, and mass production. The resulting device had a micronozzle with an orifice inner and outer diameter of 220 and 320 µm, respectively, and an extruded height of 250 µm. When the microchamber was filled with an ethanol gel and activated, the resulting ethanol vapor jet increased the permeability of human cadaver epidermis to a model compound, calcein, by approximately 17 times, which is attributed to thermal and chemical disruption of stratum corneum structure. This thermal microjet system can serve as a tool not only for transdermal drug delivery, but also for a variety of biomedical applications.

A thermal microjet system with tapered micronozzles fabricated by inclined UV lithography for transdermal drug delivery

International Nuclear Information System (INIS)

Yoon, Yong-Kyu; Park, Jung-Hwan; Lee, Jeong-Woo; Prausnitz, Mark R; Allen, Mark G

2011-01-01

Transdermal drug delivery can be enabled by various methods that increase the permeability of the skin's outer barrier of stratum corneum, including skin exposure to heat and chemical enhancers, such as ethanol. Combining these approaches for the first time, in this study we designed a microdevice consisting of an array of microchambers filled with ethanol that is vaporized using an integrated microheater and ejected through a micronozzle contacting the skin surface. In this way, we hypothesize that the hot ethanol vapor can increase skin permeability upon contacting the skin surface. The tapered micronozzle and the microchamber designed for this application were realized using proximity-mode inclined rotational ultraviolet lithography, which facilitates easy fabrication of complex three-dimensional structures, convenient integration with other functional layers, low fabrication cost, and mass production. The resulting device had a micronozzle with an orifice inner and outer diameter of 220 and 320 µm, respectively, and an extruded height of 250 µm. When the microchamber was filled with an ethanol gel and activated, the resulting ethanol vapor jet increased the permeability of human cadaver epidermis to a model compound, calcein, by approximately 17 times, which is attributed to thermal and chemical disruption of stratum corneum structure. This thermal microjet system can serve as a tool not only for transdermal drug delivery, but also for a variety of biomedical applications.

Diffusion of [2-14C]diazepam across hairless mouse skin and human skin

International Nuclear Information System (INIS)

Koch, R.L.; Palicharla, P.; Groves, M.J.

1987-01-01

The objectives of this study were to investigate the absorption of diazepam applied topically to the hairless mouse in vivo and to determine the diffusion of diazepam across isolated hairless mouse skin and human skin. [ 14 C]Diazepam was readily absorbed after topical administration to the intact hairless mouse, a total of 75.8% of the 14 C-label applied being recovered in urine and feces. Diazepam was found to diffuse across human and hairless mouse skin unchanged in experiments with twin-chambered diffusion cells. The variation in diffusion rate or the flux for both human and mouse tissues was greater among specimens than between duplicate or triplicate trials for a single specimen. Fluxes for mouse skin (stratum corneum, epidermis, and dermis) were greater than for human skin (stratum corneum and epidermis): 0.35-0.61 microgram/cm2/h for mouse skin vs 0.24-0.42 microgram/cm2/h for human skin. The permeability coefficients for mouse skin ranged from 1.4-2.4 X 10(-2)cm/h compared with 0.8-1.4 X 10(-2)cm/h for human skin. Although human stratum corneum is almost twice the thickness of that of the hairless mouse, the diffusion coefficients for human skin were 3-12 times greater (0.76-3.31 X 10(-6) cm2/h for human skin vs 0.12-0.27 X 10(-6) cm2/h for hairless mouse) because of a shorter lag time for diffusion across human skin. These differences between the diffusion coefficients and diffusion rates (or permeability coefficients) suggest that the presence of the dermis may present some barrier properties. In vitro the dermis may require complete saturation before the diazepam can be detected in the receiving chamber

Coffee polyphenols extracted from green coffee beans improve skin properties and microcirculatory function.

Science.gov (United States)

Fukagawa, Satoko; Haramizu, Satoshi; Sasaoka, Shun; Yasuda, Yuka; Tsujimura, Hisashi; Murase, Takatoshi

2017-09-01

Coffee polyphenols (CPPs), including chlorogenic acid, exert various physiological activities. The purpose of this study was to investigate the effects of CPPs on skin properties and microcirculatory function in humans. In this double-blind, placebo-controlled study, 49 female subjects with mildly xerotic skin received either a test beverage containing CPPs (270 mg/100 mL/day) or a placebo beverage for 8 weeks. The ingestion of CPPs significantly lowered the clinical scores for skin dryness, decreased transepidermal water loss, skin surface pH, and increased stratum corneum hydration and the responsiveness of skin blood flow during local warming. Moreover, the amounts of free fatty acids and lactic acid in the stratum corneum significantly increased after the ingestion of CPPs. These results suggest that an 8-week intake of CPPs improve skin permeability barrier function and hydration, with a concomitant improvement in microcirculatory function, leading to efficacy in the alleviation of mildly xerotic skin.

Noninvasive evaluation of the barrier properties of the skin

Directory of Open Access Journals (Sweden)

Utz S.R.

2014-09-01

Full Text Available Skin as an organ of protection covers the body and accomplishes multiple defensive functions. The intact skin represents a barrier to the uncontrolled loss of water, proteins, and plasma components from the organism. Due to its complex structure, the epidermal barrier with its major component, stratum corneum, is the rate-limiting unit for the penetration of exogenous substances through the skin. The epidermal barrier is not a static structure. The permeability barrier status can be modified by different external and internal factors such as climate, physical stressors, and a number of skin and systemic diseases. Today, different non-invasive approaches are used to monitor the skin barrier physical properties in vivo. The quantification of parameters such as transepidermal water loss, stratum corneum hydration, and skin surface acidity is essential for the integral evaluation of the epidermal barrier status. This paper will allow the readership to get acquainted with the non-invasive, in vivo methods for the investigation of the skin barrier.

In vivo confocal Raman microscopic determination of depth profiles of the stratum corneum lipid organization influenced by application of various oils.

Science.gov (United States)

Choe, ChunSik; Schleusener, Johannes; Lademann, Jürgen; Darvin, Maxim E

2017-08-01

The intercellular lipids (ICL) of stratum corneum (SC) play an important role in maintaining the skin barrier function. The lateral and lamellar packing order of ICL in SC is not homogenous, but rather depth-dependent. This study aimed to analyze the influence of the topically applied mineral-derived (paraffin and petrolatum) and plant-derived (almond oil and jojoba oil) oils on the depth-dependent ICL profile ordering of the SC in vivo. Confocal Raman microscopy (CRM), a unique tool to analyze the depth profile of the ICL structure non-invasively, is employed to investigate the interaction between oils and human SC in vivo. The results show that the response of SC to oils' permeation varies in the depths. All oils remain in the upper layers of the SC (0-20% of SC thickness) and show predominated differences of ICL ordering from intact skin. In these depths, skin treated with plant-derived oils shows more disordered lateral and lamellar packing order of ICL than intact skin (p0.1), except plant-derived oils at the depth 30% of SC thickness. In the deeper layers of the SC (60-100% of SC thickness), no difference between ICL lateral packing order of the oil-treated and intact skin can be observed, except that at the depths of 70-90% of the SC thickness, where slight changes with more disorder states are measured for plant-derived oil treated skin (p<0.1), which could be explained by the penetration of free fatty acid fractions in the deep-located SC areas. Both oil types remain in the superficial layers of the SC (0-20% of the SC thickness). Skin treated with mineral- and plant-derived oils shows significantly higher disordered lateral and lamellar packing order of ICL in these layers of the SC compared to intact skin. Plant-derived oils significantly changed the ICL ordering in the depths of 30% and 70-90% of the SC thickness, which is likely due to the penetration of free fatty acids in the deeper layers of the SC. Copyright © 2017 Japanese Society for

Variation of skin surface pH, sebum content and stratum corneum hydration with age and gender in a large Chinese population.

Science.gov (United States)

Man, M Q; Xin, S J; Song, S P; Cho, S Y; Zhang, X J; Tu, C X; Feingold, K R; Elias, P M

2009-01-01

Evidence suggests the importance of skin biophysical properties in predicting diseases and in developing appropriate skin care. The results to date of studies on skin surface pH, stratum corneum (SC) hydration and sebum content in both genders and at various ages have been inconclusive, which was in part due to small sample size. Additionally, little is known about the skin physical properties of Asian, especially Chinese, subjects. In the present study, we assess the difference in skin surface pH, sebum content and SC hydration at various ages and in both genders in a large Chinese population without skin diseases. 713 subjects (328 males and 385 females) aged 0.5-94 years were enrolled in this study. The subjects were divided by age into 5 groups, i.e., 0-12, 13-35, 36-50, 51-70 and over 70 years old. A multifunctional skin physiology monitor was used to measure SC hydration, skin surface pH and sebum content on both the forehead and the forearms. In males, the highest sebum content was found on the forearm and the forehead in the age groups 36-50 (93.47 +/- 10.01 microg/cm(2)) and 51-70 years (9.16 +/- 1.95 microg/cm(2)), while in females, the highest sebum content was found on the forearm and the forehead in the age groups 13-35 (61.91 +/- 6.12 microg/cm(2)) and 51-70 years (7.54 +/- 2.55 microg/cm(2)). The forehead sebum content was higher in males aged 13-70 years than in age-matched females; the sebum content on the forehead in both males and females was higher than that on the forearm. Skin surface pH on the forehead of both males and females over the age of 70 years was higher than that in younger groups. SC hydration on the forehead in both males and females was lower above the age of 70, and the one in males aged 13-35 was higher than that in females (43.99 +/- 1.88 vs. 36.38 +/- 1.67 AU, p pH, sebum content and SC hydration vary with age, gender and body site. Copyright 2009 S. Karger AG, Basel.

Movement of the water-oil contact during operation of a single well in an inclined stratum

Energy Technology Data Exchange (ETDEWEB)

Kazymov, A Sh

1965-01-01

In this theoretical study the author develops equations which describe the movement of an oil-water interface toward a single well in an inclined stratum. The equations apply even if viscosities, densities, and permeabilities vary from place to place.

Copaiba oil enhances in vitro/in vivo cutaneous permeability and in vivo anti-inflammatory effect of celecoxib.

Science.gov (United States)

Quiñones, Oliesia Gonzalez; Hossy, Bryan Hudson; Padua, Tatiana Almeida; Miguel, Nádia Campos de Oliveira; Rosas, Elaine Cruz; Ramos, Mônica Freiman de Souza; Pierre, Maria Bernadete Riemma

2018-03-29

The aim of this article was to use copaiba oil (C.O) to improve skin permeability and topical anti-inflammatory activity of celecoxib (Cxb). Formulations containing C.O (1-50%) were associated with Cxb (2%). In vitro skin permeability studies were conducted using porcine ear skin. Histological analysis of the hairless mice skin samples after application of formulations was achieved with the routine haematoxylin/eosin technique. The anti-inflammatory activity was assessed using the AA-induced ear oedema mice model. The formulation containing 25% C.O promoted the highest levels of in vitro Cxb permeation through pig ear skin, retention in the stratum corneum (SC) and epidermis/dermis of pig ear skin in vitro (~5-fold) and hairless mice skin in vivo (~2.0-fold), as compared with the control formulation. At 25%, C.O caused SC disorganization and increased cell infiltration and induced angiogenesis without clear signs of skin irritation. The formulation added to 25% C.O as adjuvant inhibited ear oedema and protein extravasation by 77.51 and 89.7%, respectively, and that it was, respectively, 2.0- and 3.4-fold more efficient than the commercial diethylammonium diclofenac cream gel to suppress these inflammatory parameters. 25% C.O is a potential penetration enhancer for lipophilic drugs like Cxb that can improve cutaneous drug penetration and its anti-inflammatory activity. © 2018 Royal Pharmaceutical Society.

The acyl-CoA binding protein is required for normal epidermal barrier function in mice

DEFF Research Database (Denmark)

Bloksgaard, Maria; Bek, Signe; Marcher, Ann-Britt

2012-01-01

(+/+) and ACBP(-/-) mice showed very similar composition, except for a significant and specific decrease in the very long chain free fatty acids (VLC-FFA) in stratum corneum of ACBP(-/-) mice. This finding indicates that ACBP is critically involved in the processes that lead to production of stratum corneum VLC......The acyl-CoA binding protein (ACBP) is a 10 kDa intracellular protein expressed in all eukaryotic species. Mice with targeted disruption of Acbp (ACBP(-/-) mice) are viable and fertile but present a visible skin and fur phenotype characterized by greasy fur and development of alopecia and scaling...... with age. Morphology and development of skin and appendages are normal in ACBP(-/-) mice; however, the stratum corneum display altered biophysical properties with reduced proton activity and decreased water content. Mass spectrometry analyses of lipids from epidermis and stratum corneum of ACBP...

The effect of microneedles on the skin permeability and antitumor activity of topical 5-fluorouracil

Directory of Open Access Journals (Sweden)

Youssef W. Naguib

2014-02-01

Full Text Available Topical 5-fluorouracil (5-FU is approved for the treatment of superficial basal cell carcinoma and actinic keratosis. However, 5-FU suffers from poor skin permeation. Microneedles have been successfully applied to improve the skin permeability of small and large molecules, and even nanoparticles, by creating micron-sized pores in the stratum corneum layer of the skin. In this report, the feasibility of using microneedles to increase the skin permeability of 5-FU was tested. Using full thickness mouse skin mounted on Franz diffusion apparatus, it was shown that the flux of 5-FU through the skin was increased by up to 4.5-fold when the skin was pretreated with microneedles (500 μm in length, 50 μm in base diameter. In a mouse model with B16-F10 mouse melanoma cells implanted in the subcutaneous space, the antitumor activity of a commercially available 5-FU topical cream (5% was significantly enhanced when the cream was applied on a skin area that was pretreated with microneedles, as compared to when the cream was simply applied on a skin area, underneath which the tumor cells were implanted, and without pretreatment of the skin with microneedles. Fluorouracil is not approved for melanoma therapy, but the clinical efficacy of topical 5-FU against tumors such as basal cell carcinoma may be improved by integrating microneedle technology into the therapy.

Stratum corneum lipid liposome-encapsulated panomycocin: preparation, characterization, and the determination of antimycotic efficacy against Candida spp. isolated from patients with vulvovaginitis in an in vitro human vaginal epithelium tissue model.

Science.gov (United States)

İzgü, Fatih; Bayram, Günce; Tosun, Kübra; İzgü, Demet

2017-01-01

In this study, a liposomal lyophilized powder formulation of panomycocin was developed for therapeutic purposes against vulvovaginal candidiasis which affects 80% of women worldwide. Panomycocin is a potent antimycotic protein secreted by the yeast Wickerhamomyces anomalus NCYC 434. This study involved the preparation of panomycocin-loaded stratum corneum lipid liposomes (SCLLs), characterization of the SCLLs, and determination of antimycotic efficacy of the formulation against Candida albicans and Candida glabrata clinical vaginal isolates in a human vaginal epithelium tissue model. The encapsulation and loading efficiencies of SCLLs were 73% and 76.8%, respectively. In transmission electron microscopy images, the SCLLs appeared in the submicron size range. Dynamic light scattering analyses showed that the SCLLs had uniform size distribution. Zeta potential measurements revealed stable and positively charged SCLLs. In Fourier transform infrared spectroscopy analyses, no irreversible interactions between the encapsulated panomycocin and the SCLLs were detected. The SCLLs retained >98% of encapsulated panomycocin in aqueous solution up to 12 hours. The formulation was fungicidal at the same minimum fungicidal concentration values for non-formulated pure panomycocin when tested on an in vitro model of vaginal candidiasis. This is the first study in which SCLLs and a protein as an active ingredient have been utilized together in a formulation. The results obtained in this study led us to conduct further preclinical trials of this formulation for the development of an effective topical anti-candidal drug with improved safety.

Factors of skin decontamination as derived from experimental studies

International Nuclear Information System (INIS)

Pratzel, H.G.

1992-01-01

The processes occuring during radioactive contamination of the skin are reminiscent of those observed in connection with skin penetration by drugs. Explained are the laws determining the penetration of substances through the skin surface, their spreading between the corneocystes into the deeper layers of the stratum corneum and their final concentrations, the decrease of which with the depth of the corneal layer can be described by an exponential curve. The extent to which the penetrating substances are transferred from the solvent to the corneal layer's lipid phase depends on their relative solubility. The intercellular lipid layer in the lower third of the stratum corneum creates the greatest obstacle to permeation through the skin. The lipid content in this part of the corneal layer is seen to be inversely proportional to the degree of natural barrier dysfunction and, thus, to permeation. For measurements of skin permeation, experiments were performed in young pigs using aqueous radioactive solutions. Part of the substances penetrated into the organism through the follicles, where the corneal layer is more permeable. In cases of very hairy skin the amount of substance deposited as a result of additional follicle penetration is seen to be higher. The greatest proportion of radioactivity by far is taken up into the stratum corneum, while only little is seen to reach the follicles and even less the deeper layers of the skin. Decontamination of the skin cannot be carried out for areas beyond the boundary of the corneal layer. (orig./HP) [de

LOCALIZATION OF PERMEABILITY BARRIERS IN THE FROG SKIN EPITHELIUM

Science.gov (United States)

Martinez-Palomo, A.; Erlij, D.; Bracho, H.

1971-01-01

Ruthenium red and colloidal lanthanum were used to determine the site of the structural barriers to diffusion within the intercellular spaces of frog skin epithelium. Electron micrographs show that occluding zonules located at the outer border of the stratum corneum and at the outer layer of the stratum granulosum are true tight junctions since they are impermeable to these tracers. Measurement of 140La uptake by the living skin shows that lanthanum moves across the external surface of the skin readily, into and out of a compartment that has a limited capacity and is bounded on its internal side by a barrier impermeable to lanthanum. Examination of these skins with the electron microscope suggests that the compartment is localized between the external membrane of the cells at the outer layer of the s. granulosum and at the outermost surface of the skin. These observations and other findings described in the literature indicate that the site of the external high resistance barrier of the frog skin is localized at the outer border of the s. granulosum. PMID:4329611

Impact of the ceramide subspecies on the nanostructure of stratum corneum lipids using neutron scattering and molecular dynamics simulations. Part I: impact of CER[NS].

Science.gov (United States)

Schmitt, Thomas; Gupta, Rakesh; Lange, Stefan; Sonnenberger, Stefan; Dobner, Bodo; Hauß, Thomas; Rai, Beena; Neubert, Reinhard H H

2018-05-30

For this study mixtures based on the ceramides [NS] (NS = non-hydroxy-sphingosine) and [AP] (AP = α-hydroxy-phytosphingosine) in a 2:1 and 1:2 ratio, together with cholesterol and lignoceric acid, were investigated. These mixtures are modelling the uppermost skin layer, the stratum corneum. Neutron diffraction, utilizing specifically deuterated ceramide molecules, was used to obtain a maximum amount of experimental detail. Highly detailed molecular dynamics simulations were used to generate even more information from the experimental data. It was possible to observe a single lamellar phase for both systems. They had a lamellar repeat distance of 5.43 ± 0.05 nm for the [NS]/[AP] 2:1 and a slightly shorter one of 5.34 ± 0.05 nm for the 1:2 system. The structure and water content was uninfluenced by excess humidity. Both the experimental and simulation data indicated slightly tilted ceramides, with their C24 chains overlapping in the lamellar mid-plane. This arrangement is well comparable to systems investigated before. The structure of both systems, except for the differing repeat distance, looks similar at first. However, on a smaller scale there were various distinct differences, demonstrating only low redundancy between the different ceramide species, despite only minor chemical differences. The mainly ceramide [AP] determined 1:2 system has a slightly smaller repeat distance. This is a result of a tighter arrangement of the lipids chain along the bilayer normal and increased overlapping of the long chains in the lamellar middle. For the CER[NS] some novel features could be shown, despite it being the overall most investigated ceramide. These include the low adaptability to changed lateral interactions, leading to an increased chain opening. This effect could explain its low miscibility with other lipids. The investigated model systems allows it to directly compare results from the literature which have used ceramide [NS] to the most recent

Effects of vehicle on the uptake and elimination kinetics of capsaicinoids in human skin in vivo

International Nuclear Information System (INIS)

Pershing, Lynn K.; Reilly, Christopher A.; Corlett, Judy L.; Crouch, Dennis J.

2004-01-01

While the physiologic and molecular effects of capsaicinoids have been extensively studied in various model systems by a variety of administration routes, little is known about the uptake and elimination kinetic profiles in human skin following topical exposure. The present study evaluated the uptake and elimination kinetics of capsaicinoids in human stratum corneum following a single topical exposure to 3% solutions containing 55% capsaicin, 35% dihydrocapsaicin, and 10% other analogues prepared in three vehicles: mineral oil (MO), propylene glycol (PG), and isopropyl alcohol (IPA). Capsaicinoid solutions were evaluated simultaneously in a random application pattern on the volar forearms of 12 subjects using a small, single 150-μg dose. Capsaicin and dihydrocapsaicin were recovered from human skin using commercial adhesive discs to harvest stratum corneum from treated sites. Capsaicinoids were extracted from the stratum corneum-adhesive discs and quantified by liquid chromatography/mass spectroscopy (LC/MS). Both capsaicinoids were detected in stratum corneum 1 min after application with all vehicles and achieved a pseudo-steady state shortly thereafter. IPA delivered three times greater capsaicin and dihydrocapsaicin into the human stratum corneum than PG or MO at all time points investigated. The C max of capsaicin in IPA, PG, and MO was 16.1, 6.2, and 6.5 μg, respectively. The dihydrocapsaicin content was 60% of capsaicin with all vehicles. The estimated T half of capsaicin and dihydrocapsaicin in the three vehicles was similar (24 h). Thus, maximal cutaneous capsaicinoid concentrations were achieved quickly in the human stratum corneum and were concentration and vehicle dependent. In contrast, capsaicinoid half-life was long and vehicle independent

Directions of flow of the water-bearing stratum in Friuli (NE Italy)

Science.gov (United States)

Cucchi, F.; Affatato, A.; Andrian, L.; Devoto, S.; Mereu, A.; Oberti, S.; Piano, C.; Rondi, V.; Zini, L.

2003-04-01

Flow directions of the water -- bearing stratum were executed with a Thermal Flowmeter in the Northern Friuli Plain. This type of instrument used is made up by a heater, a compass and various sensors of temperature. It is connected to an outside computer. It measures the induced thermal currents and identifies the direction and the intensity of the flow. The Thermal Flowmeter can be used in wells of little diameter and for big depths. The campaign of measures, about a hundred, confirms the general correspondence between the directions of the flows obtained from the water table and those measured through the Flowmeter in the permeable bodies with primary permeability. Different flow directions compared to the general picture were noticed in the conglomerate bodies, because of a secondary permeability. Direction changes are also noticed for the heterogeneity of the sediments which constitute the aquifer to big and to little scale.

Avaliação da influência de tensoativos na pele de muda de cobra (Bothrops jararaca e Spilotis pullatus) por espectroscopia fatoacústica no infravermelho, calorimetria exploratória diferencial e espectroscopia Raman

OpenAIRE

Aurea Cristina Lemos Lacerda

2004-01-01

A influência dos tensoativos lauril sulfato de sódio, cloreto de cetil trimetil amônio e álcool láurico etoxilado com 12 moles de óxido de etileno sobre o stratum corneum da pele de muda das cobras Bothrops jararaca e Spilotis pullatus foi avaliada através das técnicas biofísicas de PAS-FTIR, FT-Raman e DSC. Foram utilizadas soluções dos tensoativos em concentrações acima e abaixo da cmc e tratamentos por 4 e 8 horas (stratum corneum íntegro) e por 12 horas (stratum corneum após a remoção mec...

Dynamic characterization of hydrophobic and hydrophilic solutes in oleic-acid enhanced transdermal delivery using two-photon fluorescence microscopy

Energy Technology Data Exchange (ETDEWEB)

Tseng, Te-Yu; Yang, Chiu-Sheng; Chen, Yang-Fang [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Tsai, Tsung-Hua [Department of Dermatology, Far Eastern Memorial Hospital, New Taipei City, Taiwan (China); Dong, Chen-Yuan, E-mail: cydong@phys.ntu.edu.tw [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Center for Quantum Science and Engineering, National Taiwan University, Taipei, Taiwan (China); Center for Optoelectronic Biomedicine, National Taiwan University, Taipei, Taiwan (China)

2014-10-20

In this letter, we propose an efficient methodology of investigating dynamic properties of sulforhodamine B and rhodamine B hexyl ester molecules transporting across ex-vivo human stratum corneum with and without oleic acid enhancement. Three-dimensional, time-lapse fluorescence images of the stratum corneum can be obtained using two-photon fluorescence microscopy. Furthermore, temporal quantifications of transport enhancements in diffusion parameters can be achieved with the use of Fick's second law. Dynamic characterization of solutes transporting across the stratum corneum is an effective method for understanding transient phenomena in transdermal delivery of probe molecules, leading to improved delivery strategies of molecular species for therapeutic purposes.

Cholesteatoma

DEFF Research Database (Denmark)

Svane-Knudsen, Viggo; Halkierø-Sørensen, L.; Rasmussen, G.

2001-01-01

in the basal layer of the stratum granulosum, while the superior layer contained substantially fewer organelles than are found in normal skin. At the stratum granulosum/stratum corneum interface lipids secreted from Odland bodies were found in sac-like invaginations along the cell membrane but premature...... exocytosis was also frequently observed. In the intercellular spaces of the stratum corneum, multiple long sheets of lamellar structures interrupted by slits or pores enclosed the keratinized corneocytes. The intercellular spaces seemed narrow and an extracellular barrier was not found until well above...

Ethnicity and stratum corneum ceramides

DEFF Research Database (Denmark)

Jungersted, J.M.; Høgh, Julie Kaae; Hellgren, Lars

2010-01-01

method and analysed using high-performance thin layer chromatography. RESULTS: For the ceramide/cholesterol ratio we found statistically significant differences between groups, with Asians having the highest ratio (P

Effects of in Utero Exposure of C57BL/6J Mice to 2,3,7,8-Tetrachlorodibenzo-p-dioxin on Epidermal Permeability Barrier Development and Function

Science.gov (United States)

Muenyi, Clarisse S.; Carrion, Sandra Leon; Jones, Lynn A.; Kennedy, Lawrence H.; Slominski, Andrzej T.

2014-01-01

Background: Development of the epidermal permeability barrier (EPB) is essential for neonatal life. Defects in this barrier are found in many skin diseases such as atopic dermatitis. Objective: We investigated the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the development and function of the EPB. Methods: Timed-pregnant C57BL/6J mice were gavaged with corn oil or TCDD (10 μg/kg body weight) on gestation day 12. Embryos were harvested on embryonic day (E) 15, E16, E17, and postnatal day (PND) 1. Results: A skin permeability assay showed that TCDD accelerated the development of the EPB, beginning at E15. This was accompanied by a significant decrease in transepidermal water loss (TEWL), enhanced stratification, and formation of the stratum corneum (SC). The levels of several ceramides were significantly increased at E15 and E16. PND1 histology revealed TCDD-induced acanthosis and epidermal hyperkeratosis. This was accompanied by disrupted epidermal tight junction (TJ) function, with increased dye leakage at the terminal claudin-1–staining TJs of the stratum granulosum. Because the animals did not have enhanced rates of TEWL, a commonly observed phenotype in animals with TJ defects, we performed tape-stripping. Removal of most of the SC resulted in a significant increase in TEWL in TCDD-exposed PND1 pups compared with their control group. Conclusions: These findings demonstrate that in utero exposure to TCDD accelerates the formation of an abnormal EPB with leaky TJs, warranting further study of environmental exposures, epithelial TJ integrity, and atopic disease. Citation: Muenyi CS, Leon Carrion S, Jones LA, Kennedy LH, Slominski AT, Sutter CH, Sutter TR. 2014. Effects of in utero exposure of C57BL/6J mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin on epidermal permeability barrier development and function. Environ Health Perspect 122:1052–1058; http://dx.doi.org/10.1289/ehp.1308045 PMID:24904982

Human Skin Barrier Structure and Function Analyzed by Cryo-EM and Molecular Dynamics Simulation.

Science.gov (United States)

Lundborg, Magnus; Narangifard, Ali; Wennberg, Christian L; Lindahl, Erik; Daneholt, Bertil; Norlén, Lars

2018-04-24

In the present study we have analyzed the molecular structure and function of the human skin's permeability barrier using molecular dynamics simulation validated against cryo-electron microscopy data from near native skin. The skin's barrier capacity is located to an intercellular lipid structure embedding the cells of the superficial most layer of skin - the stratum corneum. According to the splayed bilayer model (Iwai et al., 2012) the lipid structure is organized as stacked bilayers of ceramides in a splayed chain conformation with cholesterol associated with the ceramide sphingoid moiety and free fatty acids associated with the ceramide fatty acid moiety. However, knowledge about the lipid structure's detailed molecular organization, and the roles of its different lipid constituents, remains circumstantial. Starting from a molecular dynamics model based on the splayed bilayer model, we have, by stepwise structural and compositional modifications, arrived at a thermodynamically stable molecular dynamics model expressing simulated electron microscopy patterns matching original cryo-electron microscopy patterns from skin extremely closely. Strikingly, the closer the individual molecular dynamics models' lipid composition was to that reported in human stratum corneum, the better was the match between the models' simulated electron microscopy patterns and the original cryo-electron microscopy patterns. Moreover, the closest-matching model's calculated water permeability and thermotropic behaviour were found compatible with that of human skin. The new model may facilitate more advanced physics-based skin permeability predictions of drugs and toxicants. The proposed procedure for molecular dynamics based analysis of cellular cryo-electron microscopy data might be applied to other biomolecular systems. Copyright © 2018. Published by Elsevier Inc.

10-Hydroxy-2-Decenoic Acid in Royal Jelly Extract Induced Both Filaggrin and Amino Acid in a Cultured Human Three-Dimensional Epidermis Model

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Lihao Gu

2017-11-01

Full Text Available Royal jelly (RJ is a natural product which the honeybee secretes as a special diet for a queen bee. It is one of the natural products in which various functionalities, such as antibacterial effects, immunomodulating properties, and estrogen-like action, were reported. We investigated the effect of the RJ extract on the moisturizing effect by topical application in humans. The stratum corneum moisture was increased significantly after four weeks by using the RJ extract lotion compared to placebo lotion. RJ extract contained a characteristic ingredient, 10-hydroxy-2-decenoic acid (10H2DA and 10-hydroxydecanoic acid (10HDAA, etc. However, the mechanism of stratum corneum moisture and its contributing ingredient have not yet been elucidated. We have investigated the effects of 10H2DA and 10HDAA on the free amino acids content in the stratum corneum using a cultured human three-dimensional epidermis model. Additionally, the effect of 10H2DA and 10HDAA on the amounts of filaggrin (FLG and aquaporin 3 (AQP3 were investigated at the mRNA level and by immunohistochemistry using a cultured human epidermis model. It was determined that 10H2DA increases the free amino acids in the stratum corneum of the cultured human epidermis model, and that it increased FLG on both the mRNA and protein levels. On the other hand, these actions are not observed by treatment of 10HDAA. The mRNA and protein level of AQP3 did not increase with 10H2DA or 10HDAA use. It was thought that the increase in the amount of FLG and the increase in the free amino acids of the epidermis and the stratum corneum, respectively, by 10H2DA were participating in the moisturizing function of the stratum corneum by the continuous use of RJ extract lotion.

Skin hydration and lifestyle-related factors in community-dwelling older people.

Science.gov (United States)

Iizaka, Shinji

2017-09-01

This study aimed to investigate skin hydration status of the lower legs by comparing several methods and examining lifestyle-related factors in community-dwelling older people. A cross-sectional study was conducted in three community settings in Japan from autumn to winter. Participants were older people aged ≥65 years (n=118). Skin hydration status of the lower legs was evaluated by stratum corneum hydration using an electrical device, clinical symptoms by an expert's observation and the visual analogue scale. Lifestyle factors of skin care were evaluated by a self-administered questionnaire. The mean age of participants was 74.4 years and 83.9% were women. Stratum corneum hydration was significantly correlated with clinical scores by an expert's observation (rho=-0.46, Pskin, 57.5% showed low stratum corneum hydration. Hospitalization in the past year (b=-9.4, P=0.008), excessive bathing habits (b=-4.6, P=0.014), and having an outdoor hobby (b=-5.7, P=0.007) were negatively associated, and diuretics (b=11.5, P=0.002) and lotion-type moisturizer use (b=4.6, P=0.022) were positively associated with stratum corneum hydration. Stratum corneum hydration measurements show an adequate association with observation-based evaluation by an expert, but poor agreement with subjective evaluation in community-dwelling older people. Hospitalization experience and lifestyle factors are associated with skin hydration. Copyright © 2017 Elsevier B.V. All rights reserved.

Novel phytoceramides containing fatty acids of diverse chain lengths are better than a single C18-ceramide N-stearoyl phytosphingosine to improve the physiological properties of human stratum corneum

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Oh MJ

2017-09-01

Full Text Available Myoung Jin Oh,1 Young Hoon Cho,1 So Yoon Cha,1 Eun Ok Lee,2 Jin Wook Kim,2 Sun Ki Kim,2 Chang Seo Park1 1Department of Chemical and Biochemical Engineering, Dongguk University, Chung-gu, Seoul, 2LCS Biotech, Gwonseon-gu, Suwon-si, Gyeonggi-do, Republic of Korea Abstract: Ceramides in the human stratum corneum (SC are a mixture of diverse N-acylated fatty acids (FAs with different chain lengths. C24 is the major class of FAs of ceramides. However, there are also other classes of ceramides with diverse chain lengths of FAs, and these lengths generally range from C16 to C26. This study aimed to prepare several types of phytoceramide containing diverse chain lengths of N-acylated FAs and compare them with C18-ceramide N-stearoyl phytosphingosine (NP in terms of their effects on the physiological properties of the SC. We chose natural oils, such as horse fat oil, shea butter, sunflower oil, and a mixture of macadamia nut, shea butter, moringa, and meadowfoam seed oil, as sources of FAs and phytosphingosine as a sphingoid backbone to synthesize diverse phytoceramides. Each phytoceramide exhibited a distinctive formation of the lamellar structure, and their FA profiles were similar to those of their respective natural oil. The skin barrier properties, as analyzed in human skin, clearly demonstrated that all the phytoceramides improved the recovery rate of the damaged SC and enhanced hydration better than C18-ceramide NP did. In conclusion, natural oil-derived phytoceramides could represent a novel class of ceramides for cosmetic applications in the development of an ideal skin barrier moisturizer. Keywords: fatty acid, chain length, phytoceramide, skin barrier, natural oil

Correlation of the penetration enhancement with the influence of an alcohol/tocopheryl polyethylene glycol succinate (TPGS) cosolvent system on the molecular structure of the stratum corneum of nude mouse skin as examined by microscopic FTIR/DSC

Science.gov (United States)

Liou, Yi-Bo; Ho, Hsiu-O.; Chen, Shin-Yi; Sheu, Ming-Thau

2009-10-01

Tocopheryl polyethylene glycol succinate (TPGS) is a water-soluble derivative of natural source of vitamin E, which possesses a dual nature of lipophilicity and hydrophilicity, similar to a surface-active agent. The penetration enhancement of estradiol by an ethanol and TPGS cosolvent system (EtOH/TPGS) has been confirmed. In this study, the correlation of the penetration enhancement with the influence of the EtOH/TPGS cosolvent system on biophysical changes of the stratum corneum (SC) as examined by Fourier transformation infrared spectrometry differential scanning calorimetry (FTIR/DSC) was investigated. Thermotropic changes in the asymmetrical and symmetrical C-H stretching of hydrocarbon chains of lipids, and amide I and II bands that characterize the protein structure of the SC treated with different concentrations of the EtOH/TPGS cosolvent were examined in this investigation. Results demonstrated that a strong correlation of the influence on biophysical changes of the SC treated with the EtOH/TPGS cosolvent system with the penetration enhancement of estradiol by the corresponding cosolvent system was not evident. It was concluded that the incorporation of TPGS in the cosolvent system seemed only to have insignificantly modified the structural features of the SC. It was not obvious that the penetrant had encountered these modifications resulting in an improvement in the penetration of estradiol by TPGS.

Impact of the long chain omega-acylceramides on the stratum corneum lipid nanostructure. Part 1: Thermotropic phase behaviour of CER[EOS] and CER[EOP] studied using X-ray powder diffraction and FT-Raman spectroscopy.

Science.gov (United States)

Kessner, Doreen; Brezesinski, Gerald; Funari, Sergio S; Dobner, Bodo; Neubert, Reinhard H H

2010-01-01

The stratum corneum (SC), the outermost layer of the mammalian skin, is the main skin barrier. Ceramides (CERs) as the major constituent of the SC lipid matrix are of particular interest. At the moment, 11 classes of CERs are identified, but the effect of each single ceramide species is still not known. Therefore in this article, the thermotropic behaviour of the long chain omega-acylceramides CER[EOS] and CER[EOP] was studied using X-ray powder diffraction and FT-Raman spectroscopy. It was found that the omega-acylceramides CER[EOS] and CER[EOP] do not show a pronounced polymorphism which is observed for shorter chain ceramides as a significant feature. The phase behaviour of both ceramides is strongly influenced by the extremely long acyl-chain residue. The latter has a much stronger influence compared with the structure of the polar head group, which is discussed as extremely important for the appearance of a rich polymorphism. Despite the strong influence of the long chain, the additional OH-group of the phyto-sphingosine type CER[EOP] influences the lamellar repeat distance and the chain packing. The less polar sphingosine type CER[EOS] is stronger influenced by the long acyl-chain residue. Hydration is necessary for the formation of an extended hydrogen-bonding network between the polar head groups leading to the appearance of a long-periodicity phase (LPP). In contrast, the more polar CER[EOP] forms the LPP with densely packed alkyl chains already in the dry state.

Superresolution and Fluorescence Dynamics Evidence Reveal That Intact Liposomes Do Not Cross the Human Skin Barrier.

Directory of Open Access Journals (Sweden)

Jes Dreier

Full Text Available In this study we use the combination of super resolution optical microscopy and raster image correlation spectroscopy (RICS to study the mechanism of action of liposomes as transdermal drug delivery systems in human skin. Two different compositions of liposomes were applied to newly excised human skin, a POPC liposome and a more flexible liposome containing the surfactant sodium cholate. Stimulated emission depletion microscopy (STED images of intact skin and cryo-sections of skin treated with labeled liposomes were recorded displaying an optical resolution low enough to resolve the 100 nm liposomes in the skin. The images revealed that virtually none of the liposomes remained intact beneath the skin surface. RICS two color cross correlation diffusion measurements of double labeled liposomes confirmed these observations. Our results suggest that the liposomes do not act as carriers that transport their cargo directly through the skin barrier, but mainly burst and fuse with the outer lipid layers of the stratum corneum. It was also found that the flexible liposomes showed a greater delivery of the fluorophore into the stratum corneum, indicating that they functioned as chemical permeability enhancers.

Structural characterization and lipid composition of acquired cholesteatoma

DEFF Research Database (Denmark)

Bloksgaard, Maria; Svane-Knudsen, Viggo; Sørensen, Jens A

2012-01-01

HYPOTHESIS: The goal of this work is to characterize the morphology and lipid composition of acquired cholesteatoma. We hypothesize that constitutive lipid membranes are present in the cholesteatoma and resemble those found in human skin stratum corneum. METHODS: We performed a comparative...... noninvasive structural and lipid compositional study of acquired cholesteatoma and control human skin using multiphoton excitation fluorescence microscopy-related techniques and high-performance thin-layer chromatography. RESULTS: The structural arrangement of the cholesteatoma is morphologically invariant...... along a depth of more than 200 μm and resembles the stratum corneum of hyperorthokeratotic skin. Lipid compositional analyses of the cholesteatoma show the presence of all major lipid classes found in normal skin stratum corneum (ceramides, long chain fatty acids, and cholesterol). Consistent with this...

PBTK modeling demonstrates contribution of dermal and inhalation exposure components to end-exhaled breath concentrations of naphthalene.

Science.gov (United States)

Kim, David; Andersen, Melvin E; Chao, Yi-Chun E; Egeghy, Peter P; Rappaport, Stephen M; Nylander-French, Leena A

2007-06-01

Dermal and inhalation exposure to jet propulsion fuel 8 (JP-8) have been measured in a few occupational exposure studies. However, a quantitative understanding of the relationship between external exposures and end-exhaled air concentrations has not been described for occupational and environmental exposure scenarios. Our goal was to construct a physiologically based toxicokinetic (PBTK) model that quantitatively describes the relative contribution of dermal and inhalation exposures to the end-exhaled air concentrations of naphthalene among U.S. Air Force personnel. The PBTK model comprised five compartments representing the stratum corneum, viable epidermis, blood, fat, and other tissues. The parameters were optimized using exclusively human exposure and biological monitoring data. The optimized values of parameters for naphthalene were a) permeability coefficient for the stratum corneum 6.8 x 10(-5) cm/hr, b) permeability coefficient for the viable epidermis 3.0 x 10(-3) cm/hr, c) fat:blood partition coefficient 25.6, and d) other tissue:blood partition coefficient 5.2. The skin permeability coefficient was comparable to the values estimated from in vitro studies. Based on simulations of workers' exposures to JP-8 during aircraft fuel-cell maintenance operations, the median relative contribution of dermal exposure to the end-exhaled breath concentration of naphthalene was 4% (10th percentile 1% and 90th percentile 11%). PBTK modeling allowed contributions of the end-exhaled air concentration of naphthalene to be partitioned between dermal and inhalation routes of exposure. Further study of inter- and intraindividual variations in exposure assessment is required to better characterize the toxicokinetic behavior of JP-8 components after occupational and/or environmental exposures.

Are marketed topical metronidazole creams bioequivalent? Evaluation by in vivo microdialysis sampling and tape stripping methodology

DEFF Research Database (Denmark)

Garcia Ortiz, Patricia Elodia; Hansen, S H; Shah, Surendra P.

2011-01-01

To evaluate the bioequivalence of 3 marketed topical metronidazole formulations by simultaneous dermal microdialysis and stratum corneum sampling by the tape stripping methodology, and to compare the techniques as tools for the determination of bioequivalence.......To evaluate the bioequivalence of 3 marketed topical metronidazole formulations by simultaneous dermal microdialysis and stratum corneum sampling by the tape stripping methodology, and to compare the techniques as tools for the determination of bioequivalence....

Hand eczema and stratum corneum ceramides

DEFF Research Database (Denmark)

Jungersted, J. M.; Høgh, Julie Kaae; Hellgren, Lars

2015-01-01

Index (HECSI), and skin barrier susceptibility was assessed by measuring transepidermal water loss (TEWL) after a 24-hour patch test with sodium lauryl sulfate (SLS). Results: No statistically significant difference was found between groups for the lipid analysis or for skin susceptibility to SLS. We...

Detecting electroporation by assessing the time constants in the exponential response of human skin to voltage controlled impulse electrical stimulation.

Science.gov (United States)

Bîrlea, Sinziana I; Corley, Gavin J; Bîrlea, Nicolae M; Breen, Paul P; Quondamatteo, Fabio; OLaighin, Gearóid

2009-01-01

We propose a new method for extracting the electrical properties of human skin based on the time constant analysis of its exponential response to impulse stimulation. As a result of this analysis an adjacent finding has arisen. We have found that stratum corneum electroporation can be detected using this analysis method. We have observed that a one time-constant model is appropriate for describing the electrical properties of human skin at low amplitude applied voltages (30V). Higher voltage amplitudes (>30V) have been proven to create pores in the skin's stratum corneum which offer a new, lower resistance, pathway for the passage of current through the skin. Our data shows that when pores are formed in the stratum corneum they can be detected, in-vivo, due to the fact that a second time constant describes current flow through them.

Cutaneous water loss and sphingolipids in the stratum corneum of house sparrows, Passer domesticus L., from desert and mesic environments as determined by reversed phase high-performance liquid chromatography coupled with atmospheric pressure photospray ionization mass spectrometry.

Science.gov (United States)

Muñoz-Garcia, Agustí; Ro, Jennifer; Brown, Johnie C; Williams, Joseph B

2008-02-01

Because cutaneous water loss (CWL) represents half of total water loss in birds, selection to reduce CWL may be strong in desert birds. We previously found that CWL of house sparrows from a desert population was about 25% lower than that of individuals from a mesic environment. The stratum corneum (SC), the outer layer of the epidermis, serves as the primary barrier to water vapor diffusion through the skin. The avian SC is formed by layers of corneocytes embedded in a lipid matrix consisting of cholesterol, free fatty acids and two classes of sphingolipids, ceramides and cerebrosides. The SC of birds also serves a thermoregulatory function; high rates of CWL keep body temperatures under lethal limits in episodes of heat stress. In this study, we used high-performance liquid chromatography coupled with atmospheric pressure photoionization-mass spectrometry (HPLC/APPI-MS) to identify and quantify over 200 sphingolipids in the SC of house sparrows from desert and mesic populations. Principal components analysis (PCA) led to the hypotheses that sphingolipids in the SC of desert sparrows have longer carbon chains in the fatty acid moiety and are more polar than those found in mesic sparrows. We also tested the association between principal components and CWL in both populations. Our study suggested that a reduction in CWL found in desert sparrows was, in part, the result of modifications in chain length and polarity of the sphingolipids, changes that apparently determine the interactions of the lipid molecules within the SC.

Gravimetric method for in vitro calibration of skin hydration measurements.

Science.gov (United States)

Martinsen, Ørjan G; Grimnes, Sverre; Nilsen, Jon K; Tronstad, Christian; Jang, Wooyoung; Kim, Hongsig; Shin, Kunsoo; Naderi, Majid; Thielmann, Frank

2008-02-01

A novel method for in vitro calibration of skin hydration measurements is presented. The method combines gravimetric and electrical measurements and reveals an exponential dependency of measured electrical susceptance to absolute water content in the epidermal stratum corneum. The results also show that absorption of water into the stratum corneum exhibits three different phases with significant differences in absorption time constant. These phases probably correspond to bound, loosely bound, and bulk water.

Quantification of changes in skin hydration and sebum after tape stripping using infrared spectroscopy

Science.gov (United States)

Ezerskaia, A.; Pereira, S. F.; Urbach, H. P.; Varghese, B.

2017-02-01

Skin barrier function relies on well balanced water and lipid system of stratum corneum. Optimal hydration and oiliness levels are indicators of skin health and integrity. We demonstrate an accurate and sensitive depth profiling of stratum corneum sebum and hydration levels using short wave infrared spectroscopy in the spectral range around 1720 nm. We demonstrate that short wave infrared spectroscopic technique combined with tape stripping can provide morequantitative and more reliable skin barrier function information in the low hydration regime, compared to conventional biophysical methods.

Therapeutic and cosmeceutical potential of ethosomes: An overview

Directory of Open Access Journals (Sweden)

Poonam Verma

2010-01-01

Full Text Available The main disadvantage of transdermal drug delivery is the poor penetration of most compounds into the human skin. The main barrier of the skin is located within its uppermost layer, the stratum corneum (SC. Several approaches have been developed to weaken this skin barrier. One of the approaches for increasing the skin penetration of drugs and many cosmetic chemicals is the use of vesicular systems, such as, liposomes and ethosomes. Ethosomes are phospholipid-based elastic nanovesicles containing a high content of ethanol (20-45%. Ethanol is known as an efficient permeation enhancer and has been added in the vesicular systems to prepare elastic nanovesicles. It can interact with the polar head group region of the lipid molecules, resulting in the reduction of the melting point of the stratum corneum lipid, thereby increasing lipid fluidity and cell membrane permeability. The high flexibility of vesicular membranes from the added ethanol permits the elastic vesicles to squeeze themselves through the pores, which are much smaller than their diameters. Ethosomal systems are much more efficient in delivering substances to the skin in the terms of quantity and depth, than either conventional liposomes or hydroalcoholic solutions. The scope of this small review is to introduce the novel concept of ethosomes and to describe some approaches and mechanisms of stimulating topical and transdermal products with ethosomes.

Development of an in vivo animal model for skin penetration in hairless rats assessed by mass balance

DEFF Research Database (Denmark)

Simonsen, Lene; Petersen, Mads B; Benfeldt, Eva

2002-01-01

acid and (14)C-butyl salicylate were topically applied. Rapid and differentiated percutaneous absorption of both compounds were shown by urinary excretion data. For (14)C-salicylic acid the amount on the skin surface, in the stratum corneum and in the viable skin was determined. Total mass balance...... rat and free mobility throughout the test period. By consecutive tape stripping, monitored by measurements of transepidermal water loss and confirmed by histological examination of skin biopsies, 10 tape strippings were found to remove the stratum corneum completely. For assessment of the model, (14)C-salicylic...

Stratum corneum biomarkers for inflammatory skin diseases

NARCIS (Netherlands)

Koppes, S.A.

2017-01-01

This thesis focusses on development of biomarkers, obtained by a non-invasive sampling method, for skin inflammatory diseases relevant for occupational settings; irritant contact dermatitis (ICD), allergic contact dermatitis (ACD) and atopic dermatitis (AD). In various studies, in which different

Technological geological and mathematical models of petroleum stratum

International Nuclear Information System (INIS)

Zhumagulov, B.T.; Monakhov, V.N.

1997-01-01

The comparative analysis of different mathematical methods of petroleum stratum, the limit of their applicability and hydrodynamical analysis of numerical calculation's results is carried out. The problem of adaptation of the mathematical models and the identification of petroleum stratum parameters are considered. (author)

Volumetric Visualization of Human Skin

Science.gov (United States)

Kawai, Toshiyuki; Kurioka, Yoshihiro

We propose a modeling and rendering technique of human skin, which can provide realistic color, gloss and translucency for various applications in computer graphics. Our method is based on volumetric representation of the structure inside of the skin. Our model consists of the stratum corneum and three layers of pigments. The stratum corneum has also layered structure in which the incident light is reflected, refracted and diffused. Each layer of pigment has carotene, melanin or hemoglobin. The density distributions of pigments which define the color of each layer can be supplied as one of the voxel values. Surface normals of upper-side voxels are fluctuated to produce bumps and lines on the skin. We apply ray tracing approach to this model to obtain the rendered image. Multiple scattering in the stratum corneum, reflective and absorptive spectrum of pigments are considered. We also consider Fresnel term to calculate the specular component for glossy surface of skin. Some examples of rendered images are shown, which can successfully visualize a human skin.

Electroosmotic pore transport in human skin.

Science.gov (United States)

Uitto, Olivia D; White, Henry S

2003-04-01

To determine the pathways and origin of electroosmotic flow in human skin. Iontophoretic transport of acetaminophen in full thickness human cadaver skin was visualized and quantified by scanning electrochemical microscopy. Electroosmotic flow in the shunt pathways of full thickness skin was compared to flow in the pores of excised stratum corneum and a synthetic membrane pore. The penetration of rhodamine 6G into pore structures was investigated by laser scanning confocal microscopy. Electroosmotic transport is observed in shunt pathways in full thickness human skin (e.g., hair follicles and sweat glands), but not in pore openings of freestanding stratum corneum. Absolute values of the diffusive and iontophoretic pore fluxes of acetaminophen in full thickness human skin are also reported. Rhodamine 6G is observed to penetrate to significant depths (approximately 200 microm) along pore pathways. Iontophoresis in human cadaver skin induces localized electroosmotic flow along pore shunt paths. Electroosmotic forces arise from the passage of current through negatively charged mesoor nanoscale pores (e.g., gap functions) within cellular regions that define the pore structure beneath the stratum corneum.

Relationship between biochemical factors and skin symptoms in chronic venous disease.

Science.gov (United States)

Takai, Yasushi; Hiramoto, Keiichi; Nishimura, Yoshiyuki; Ooi, Kazuya

2017-05-01

Chronic venous disease (CVD) is a common venous disease of the lower extremities and patients often develop symptoms of itching and skin roughness. An easy to use and objective skin examination was recently developed that allows measurement of the level of stratum corneum content and transepidermal water loss (TEWL), which can indicate the status of the barrier function of the stratum corneum. Previous studies demonstrated that histamine production from mast cells, and tryptase and matrix metalloprotease-9 levels were associated with skin inflammation. This study aimed to clarify the relationship between dry skin and inflammatory mediators that mediate the skin symptoms of CVD subjects. The study enrolled 27 subjects with CVD and a control group consisting of 9 volunteers. The itching onset frequency was higher in women (70.4%) compared with men (50.0%). To analyze the mechanisms involved in itching we measured blood inflammatory mediators pre- and post-sclerotherapy. There was a significant decrease in Substance P, histamine, IgE, and tryptase levels post-sclerotherapy compared with those at pre-sclerotherapy. These levels were associated with the severity of itching. In addition, compared with the control subjects, there was a significant increase in the stratum corneum water content and a decrease in the TEWL in the 27 patients with CVD. This was associated with a decrease in the itching symptoms. Our findings indicate that sclerotherapy decreased levels of inflammatory mediators, increased stratum corneum water content and decreased TEWL, which coincided with reduced itching in CVD patients, indicating they might be therapeutic targets.

Biochemical and Bioimaging Evidence of Cholesterol in Acquired Cholesteatoma

DEFF Research Database (Denmark)

Thorsted, Bjarne; Bloksgaard, Maria; Groza, Alexandra

2016-01-01

: The results show that the total lipid content of the cholesteatoma matrix is similar to that of stratum corneum from skin and that the cholesteatoma matrix unquestionably contains cholesterol. The cholesterol content in the cholesteatoma matrix is increased by over 30% (w/w dry weight) compared to the control....... The cholesterol sulfate content is below 1% of the total lipids in both the cholesteatoma and the control. Cholesterol ester was reduced by over 30% when compared to the control. CONCLUSIONS: The content of cholesterol in the cholesteatoma matrix is significantly different from that in stratum corneum from skin...

Novel TGM5 mutations in acral peeling skin syndrome

NARCIS (Netherlands)

van der Velden, Jaap J. A. J.; van Geel, Michel; Nellen, Ruud G. L.; Jonkman, Marcel F.; McGrath, John A.; Nanda, Arti; Sprecher, Eli; van Steensel, Maurice A. M.; McLean, W. H. Irwin; Cassidy, Andrew J.

Acral peeling skin syndrome (APSS, MIM #609796) is a rare autosomal recessive disorder characterized by superficial exfoliation and blistering of the volar and dorsal aspects of hands and feet. The level of separation is at the junction of the stratum granulosum and stratum corneum. APSS is caused

Hardening Stratum, the Bitcoin Pool Mining Protocol

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Recabarren Ruben

2017-07-01

Full Text Available Stratum, the de-facto mining communication protocol used by blockchain based cryptocurrency systems, enables miners to reliably and efficiently fetch jobs from mining pool servers. In this paper we exploit Stratum’s lack of encryption to develop passive and active attacks on Bitcoin’s mining protocol, with important implications on the privacy, security and even safety of mining equipment owners. We introduce StraTap and ISP Log attacks, that infer miner earnings if given access to miner communications, or even their logs. We develop BiteCoin, an active attack that hijacks shares submitted by miners, and their associated payouts. We build BiteCoin on WireGhost, a tool we developed to hijack and surreptitiously maintain Stratum connections. Our attacks reveal that securing Stratum through pervasive encryption is not only undesirable (due to large overheads, but also ineffective: an adversary can predict miner earnings even when given access to only packet timestamps. Instead, we devise Bedrock, a minimalistic Stratum extension that protects the privacy and security of mining participants. We introduce and leverage the mining cookie concept, a secret that each miner shares with the pool and includes in its puzzle computations, and that prevents attackers from reconstructing or hijacking the puzzles.

Comparative enhancing effects of electret with chemical enhancers on transdermal delivery of meloxicam in vitro

International Nuclear Information System (INIS)

Cui, L L; Hou, X M; Li, G D; Jiang, J; Liang, Y Y; Xin, X

2008-01-01

Electret offers enhancing effect in transdermal drug delivery for altering of the arrangement of lipid molecules in the stratum corneum, forming many transient permeable apertures and enhancing the transdermal drug delivery. In this paper, meloxicam patch formulations were developed to make the comparative study of transdermal drug delivery between electret and chemical enhancers. Patches were made into control, electret, chemical enhancer and electret with chemical enhancer ones, according to the preparation procedure. The electret combined with chemical enhancer patch was designed to probe the incorporation between electret and chemical enhancer in transdermal drug delivery. The meloxicam release from the patch was found to increase in order of blank, chemical enhancer, electret and electret with chemical enhancer patch, in general.

Characterization of atopic skin and the effect of a hyperforin-rich cream by laser scanning microscopy

Science.gov (United States)

Meinke, Martina C.; Richter, Heike; Kleemann, Anke; Lademann, Juergen; Tscherch, Kathrin; Rohn, Sascha; Schempp, Christoph M.

2015-05-01

Atopic dermatitis (AD) is a multifactorial inflammatory skin disease that affects both children and adults in an increasing manner. The treatment of AD often reduces subjective skin parameters, such as itching, dryness, and tension, but the inflammation cannot be cured. Laser scanning microscopy was used to investigate the skin surface, epidermal, and dermal characteristics of dry and atopic skin before and after treatment with an ointment rich in hyperforin, which is known for its anti-inflammatory effects. The results were compared to subjective parameters and transepidermal water loss, stratum corneum moisture, and stratum corneum lipids. Using biophysical methods, in particular laser scanning microscopy, it was found that atopic skin has distinct features compared to healthy skin. Treatment with a hyperforin-rich ointment resulted in an improvement of the stratum corneum moisture, skin surface dryness, skin lipids, and the subjective skin parameters, indicating that the barrier is stabilized and improved by the ointment. But in contrast to the improved skin surface, the inflammation in the deeper epidermis/dermis often continues to exist. This could be clearly shown by the reflectance confocal microscopy (RCM) measurements. Therefore, RCM measurements could be used to investigate the progress in treatment of atopic dermatitis.

Effects of various vehicles on skin hydration in vivo.

Science.gov (United States)

Wiedersberg, S; Leopold, C S; Guy, R H

2009-01-01

The stratum corneum, the outermost layer of the skin, regulates the passive loss of water to the environment. Furthermore, it is well accepted that drug penetration is influenced by skin hydration, which may be manipulated by the application of moisturizing or oleaginous vehicles. Measurements of transepidermal water loss (TEWL), and of skin hydration using a corneometer, were used to assess the effect of different vehicles on stratum corneum barrier function in vivo in human volunteers. A microemulsion significantly increased skin hydration relative to a reference vehicle based on medium chain triglycerides; in contrast, Transcutol(R) lowered skin hydration. TEWL measurements confirmed these observations. Copyright 2009 S. Karger AG, Basel.

Topical application of 5-aminolevulinic acid hexyl ester and 5-aminolevulinic acid to normal nude mouse skin: Differences in protoporphyrin IX fluorescence kinetics and the role of the stratum corneum

NARCIS (Netherlands)

van den Akker, J. T.; Iani, V.; Star, W. M.; Sterenborg, H. J.; Moan, J.

2000-01-01

An important limitation of topical 5-aminolevulinic acid (ALA)-based photodetection and photodynamic therapy is that the amount of the fluorescing and photosensitizing product protoporphyrin IX (PpIX) formed is limited. The reason for this Is probably the limited diffusion of ALA through the stratum

A method for processing the critical zone of a carbonate stratum

Energy Technology Data Exchange (ETDEWEB)

Dytyuk, L T; Barsukov, A V; Bragina, O A; Kalabina, A V; Samakayev, R Kh

1982-01-01

A method is proposed for processing the critical zone of a carbonate stratum by pumping a carbonate rock solvent into it. It is distinguished by the fact that in order to increase the penetration depth of the solvent into the stratum by reducing the speed of interaction of the solvent, a solution of beta-phenoxyvinylphosphonic acid is pumped into the critical zone of the stratum.

Multiscale modeling of transdermal drug delivery

Science.gov (United States)

Rim, Jee Eun

2006-04-01

This study addresses the modeling of transdermal diffusion of drugs, to better understand the permeation of molecules through the skin, and especially the stratum corneum, which forms the main permeation barrier of the skin. In transdermal delivery of systemic drugs, the drugs diffuse from a patch placed on the skin through the epidermis to the underlying blood vessels. The epidermis is the outermost layer of the skin and can be further divided into the stratum corneum (SC) and the viable epidermis layers. The SC consists of keratinous cells (corneocytes) embedded in the lipid multi-bilayers of the intercellular space. It is widely accepted that the barrier properties of the skin mostly arises from the ordered structure of the lipid bilayers. The diffusion path, at least for lipophilic molecules, seems to be mainly through the lipid bilayers. Despite the advantages of transdermal drug delivery compared to other drug delivery routes such as oral dosing and injections, the low percutaneous permeability of most compounds is a major difficulty in the wide application of transdermal drug delivery. In fact, many transdermal drug formulations include one or more permeation enhancers that increase the permeation of the drug significantly. During the last two decades, many researchers have studied percutaneous absorption of drugs both experimentally and theoretically. However, many are based on pharmacokinetic compartmental models, in which steady or pseudo-steady state conditions are assumed, with constant diffusivity and partitioning for single component systems. This study presents a framework for studying the multi-component diffusion of drugs coupled with enhancers through the skin by considering the microstructure of the stratum corneum (SC). A multiscale framework of modeling the transdermal diffusion of molecules is presented, by first calculating the microscopic diffusion coefficient in the lipid bilayers of the SC using molecular dynamics (MD). Then a

Pseudomonas-derived ceramidase induces production of inflammatory mediators from human keratinocytes via sphingosine-1-phosphate.

Directory of Open Access Journals (Sweden)

Ami Oizumi

Full Text Available Ceramide is important for water retention and permeability barrier functions in the stratum corneum, and plays a key role in the pathogenesis of atopic dermatitis (AD. A Pseudomonas aeruginosa-derived neutral ceramidase (PaCDase isolated from a patient with AD was shown to effectively degrade ceramide in the presence of Staphylococcus aureus-derived lipids or neutral detergents. However, the effect of ceramide metabolites on the functions of differentiating keratinocytes is poorly understood. We found that the ceramide metabolite sphingosine-1-phosphate (S1P stimulated the production of inflammatory mediators such as TNF-α and IL-8 from three-dimensionally cultured human primary keratinocytes (termed "3D keratinocytes", which form a stratum corneum. PaCDase alone did not affect TNF-α gene expression in 3D keratinocytes. In the presence of the detergent Triton X-100, which damages stratum corneum structure, PaCDase, but not heat-inactivated PaCDase or PaCDase-inactive mutant, induced the production of TNF-α, endothelin-1, and IL-8, indicating that this production was dependent on ceramidase activity. Among various ceramide metabolites, sphingosine and S1P enhanced the gene expression of TNF-α, endothelin-1, and IL-8. The PaCDase-enhanced expression of these genes was inhibited by a sphingosine kinase inhibitor and by an S1P receptor antagonist VPC 23019. The TNF-α-binding antibody infliximab suppressed the PaCDase-induced upregulation of IL-8, but not TNF-α, mRNA. PaCDase induced NF-κB p65 phosphorylation. The NF-κB inhibitor curcumin significantly inhibited PaCDase-induced expression of IL-8 and endothelin-1. VPC 23019 and infliximab inhibited PaCDase-induced NF-κB p65 phosphorylation and reduction in the protein level of the NF-κB inhibitor IκBα. Collectively, these findings suggest that (i 3D keratinocytes produce S1P from sphingosine, which is produced through the hydrolysis of ceramide by PaCDase, (ii S1P induces the production

TRANSDERMAL PERMEABILITY OF ESTRADIOL THROUGH THE HUMAN SKIN OF DIFFERENT BODY REGIONS IN VITRO

Institute of Scientific and Technical Information of China (English)

CHENGuo-Shen; GONGSai-Jun; DUJie; MARun-Zhen; ZHOURong-Rong; LIULiang-Chu

1989-01-01

Transdermal permeability of estradiol was carried out by using Valia-Chien double compartment permeation cells for the following regions of intact skin and skin without stratum corncum: chest, abdomen, hip, upper arm, thigh and back. The estradiol permeation rates and accumulative amounts within 72h in vitro were examined by HPLC. The results showed that the permeation rates of intact skin from different regions of the body

Mechanical properties of a Gelidium corneum edible film containing catechin and its application in sausages.

Science.gov (United States)

Ku, K-J; Hong, Y-H; Song, K B

2008-04-01

We prepared an edible Gelidium corneum (GC) film containing catechin and examined the microbial growth and quality change during storage of sausages packaged with the film. Incorporation of catechin in the film improved film tensile strength and water vapor permeability. The film's antimicrobial activity against Eschericha coli O157:H7 increased with increasing catechin concentrations and resulted in a decrease in the populations of the bacteria by 1.93 log CFU/g at 150 mg of catechin. For the sausage samples inoculated with E. coli O157:H7 and Listeria monocytogenes, the samples packed with the GC film showed a decrease in populations of E. coli O157:H7 and L. monocytogenes by 1.81 and 1.44 log CFU/g, respectively, compared to the control after 5 d of storage. In addition, the sausage samples packed with the GC film had lower degrees of lipid oxidation. The results suggest that sausages can be packed with GC film to extend shelf life.

Emulsion-Based Intradermal Delivery of Melittin in Rats

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Sang Mi Han

2017-05-01

Full Text Available Bee venom (BV has long been used as a traditional medicine. The aim of the present study was to formulate a BV emulsion with good rheological properties for dermal application and investigate the effect of formulation on the permeation of melittin through dermatomed rat skin. A formulated emulsion containing 1% (w/v BV was prepared. The emulsion was compared with distilled water (DW and 25% (w/v N-methyl-2-pyrrolidone (NMP in DW. Permeation of melittin from aqueous solution through the dermatomed murine skin was evaluated using the Franz diffusion cells. Samples of receptor cells withdrawn at pre-determined time intervals were measured for melittin amount. After the permeation study, the same skin was used for melittin extraction. In addition, a known amount of melittin (5 μg/mL was added to stratum corneum, epidermis, and dermis of the rat skin, and the amount of melittin was measured at pre-determined time points. The measurement of melittin from all samples was done with HPLC-MS/MS. No melittin was detected in the receptor phase at all time points in emulsion, DW, or NMP groups. When the amount of melittin was further analyzed in stratum corneum, epidermis, and dermis from the permeation study, melittin was still not detected. In an additional experiment, the amount of melittin added to all skin matrices was corrected against the amount of melittin recovered. While the total amount of melittin was retained in the stratum corneum, less than 10% of melittin remained in epidermis and dermis within 15 and 30 min, respectively. Skin microporation with BV emulsion facilitates the penetration of melittin across the stratum corneum into epidermis and dermis, where emulsified melittin could have been metabolized by locally-occurring enzymes.

Emulsion-Based Intradermal Delivery of Melittin in Rats.

Science.gov (United States)

Han, Sang Mi; Kim, Se Gun; Pak, Sok Cheon

2017-05-19

Bee venom (BV) has long been used as a traditional medicine. The aim of the present study was to formulate a BV emulsion with good rheological properties for dermal application and investigate the effect of formulation on the permeation of melittin through dermatomed rat skin. A formulated emulsion containing 1% ( w / v ) BV was prepared. The emulsion was compared with distilled water (DW) and 25% ( w / v ) N -methyl-2-pyrrolidone (NMP) in DW. Permeation of melittin from aqueous solution through the dermatomed murine skin was evaluated using the Franz diffusion cells. Samples of receptor cells withdrawn at pre-determined time intervals were measured for melittin amount. After the permeation study, the same skin was used for melittin extraction. In addition, a known amount of melittin (5 μg/mL) was added to stratum corneum, epidermis, and dermis of the rat skin, and the amount of melittin was measured at pre-determined time points. The measurement of melittin from all samples was done with HPLC-MS/MS. No melittin was detected in the receptor phase at all time points in emulsion, DW, or NMP groups. When the amount of melittin was further analyzed in stratum corneum, epidermis, and dermis from the permeation study, melittin was still not detected. In an additional experiment, the amount of melittin added to all skin matrices was corrected against the amount of melittin recovered. While the total amount of melittin was retained in the stratum corneum, less than 10% of melittin remained in epidermis and dermis within 15 and 30 min, respectively. Skin microporation with BV emulsion facilitates the penetration of melittin across the stratum corneum into epidermis and dermis, where emulsified melittin could have been metabolized by locally-occurring enzymes.

Treatment of acute radiodermatitis with an oil-in-water emulsion following radiation therapy for breast cancer. A controlled, randomized trial

International Nuclear Information System (INIS)

Jensen, Jens-Michael; Gau, Tanja; Foelster-Holst, Regina; Proksch, Ehrhardt; May, Theodor

2011-01-01

A side effect of radiotherapy for breast cancer is acute radiodermatitis. It is a common practice to keep irradiated skin dry on account of data from the 1950s that suggested this regimen limits dermatitis. However, severe dryness of the skin induced by irradiation results in itching and discomfort. Dry skin is characterized by scaliness, epidermal barrier dysfunction, and reduced stratum corneum hydration, and these signs and symptoms are reduced by treatment with an emulsion. We performed a randomized, controlled, open-label study with 66 patients (ITT population), treating the irradiated skin in one group (n = 34) with an oil-in-water emulsion (WO1932), while leaving the other group untreated (n = 32). Clinical scoring (ONS radiation skin reaction scoring, pruritus) and biophysical measurements (stratum corneum hydration and transepidermal water loss (TEWL), as a marker of skin barrier function) were determined at day 1 (directly after termination of the radiation therapy), day 8, and day 47 (± 7). Irradiation increased the ONS score and pruritus, whereas skin hydration and TEWL were reduced. The primary hypothesis that the increase in skin hydration was significantly greater in the emulsion-treated compared to the untreated group as early as after 8 days of treatment could not be confirmed. At the end of the study (day 47 ± 7), however, normalization of stratum corneum hydration was more advanced in the treatment group compared to the untreated group and nearly reached the values of the contralateral healthy breast skin. ONS score and pruritus also revealed an advantage for the emulsion-treated group. TEWL did not show significant changes during emulsion treatment. No adverse events were caused by the treatment regimens. Treatment of radiodermatitis with an oil-in-water emulsion was well tolerated, enhanced stratum corneum hydration, improved clinical indicators, and provided relief from itching. (orig.)

In vivo skin moisturizing measurement by high-resolution 3 Tesla magnetic resonance imaging.

Science.gov (United States)

Mesrar, J; Ognard, J; Garetier, M; Chechin, D; Misery, L; Ben Salem, D

2017-08-01

Magnetic resonance imaging (MRI) is rarely used for the exploration of skin, even if studies have validated both feasibility of skin MRI and its interest for anatomical, physiological, and biochemical study of the skin. The purpose of this study is to explore moisturizing of the different skin layers using 3-T scan. An MRI of the heel's skin was performed using a 23 mm coil diameter on a 3T scan with a FFE (Fast Field Echo) 3D T1-weighted sequence and a TSE (Turbo Spin Echo) calculation T2-weighted sequence (pixels size of respectively 60 and 70 μm). This study was conducted on 35 healthy volunteers, who were scanned before applying moisturizer topic and 1 h after applying it. Region of interest in the stratum corneum, the epidermis and the dermis were generated on the T2 mapping. The thickness of each layer was measured. The T1 sequence allowed accurate cross-examination repositioning to ensure the comparability of the measurements. Among the 35 cases, two were excluded from the analysis because of movement artifacts. Measurements before and after moisturizer topic application displayed a T2 increase of 48.94% (P < 0.0001) in the stratum corneum and of 5.45% (P < 0.0001) in the epidermis yet without significant difference in the dermis. There was no significant link between the thickness of the stratum corneum and the T2 increase. However, there was a strong correlation between the thickness of the stratum corneum and the thickness of the epidermis (P < 0.001; rhô=0.72). High-resolution MRI allows fine exploration of anatomical and physiological properties of the skin and can further be used to extend the studies of skin hydration. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Formation of a protection film on the human skin by microparticles

International Nuclear Information System (INIS)

Lademann, J; Schanzer, S; Richter, H; Knorr, F; Sterry, W; Patzelt, A; Antoniou, C

2008-01-01

Laser scanning microscopy and tape stripping, in combination with optical methods, were used to analyze the distribution and penetration of a barrier cream into the horny layer (stratum corneum) of the human skin under in vivo conditions. The barrier cream contained microparticles of 10 – 100 μm loaded with antioxidant substances. The cream was designed for protection of the skin surface against the destructive action of free radicals, produced by systemically applied chemotherapeutic agents reaching the skin surface via the sweat. Both methods were able to demonstrate that the barrier cream was distributed homogeneously on the skin surface forming a protection film. A penetration into deeper parts of the stratum corneum (SC) was not observed

Water exchange and permeability properties of the skin in three species of amphibious sea snakes (Laticauda spp.).

Science.gov (United States)

Lillywhite, H B; Menon, J G; Menon, G K; Sheehy, C M; Tu, M C

2009-06-01

Evolutionary transitions between different environmental media such as air and water pose special problems with respect to skin permeability because of the dramatic changes in the driving gradients and nature of water exchange processes. Also, during the transitional periods prior to complete adaptation to a new medium, the skin is exposed to two very different sets of environmental conditions. Here, we report new data for transepidermal evaporative water loss (TEWL) and cutaneous resistance to evaporative water loss (R(s)) of sea snakes that are transitional in the sense of being amphibious and semi-terrestrial. We investigated three species of sea kraits (Elapidae: Laticaudinae) that are common to Orchid Island (Lanyu), Taiwan. Generally, R(s) of all three species is lower than that characteristic of terrestrial/xeric species of snakes measured in other taxa. Within Laticauda, R(s) is significantly greater (TEWL lower) in the more terrestrial species and lowest (TEWL highest) in the more aquatic species. Previously reported losses of water from snakes kept in seawater exhibit a reversed trend, with lower rates of loss in the more aquatic species. These data suggest selection for adaptive traits with respect to increasing exposure to the marine environment. Thus, a countergradient of traits is reflected in decreased TEWL in aerial environments and decreased net water efflux in marine environments, acting simultaneously in the three species. The pattern for TEWL correlates with ultrastructural evidence for increased lipogenesis in the stratum corneum of the more terrestrial species. The skin surfaces of all three species are hydrophobic. Species differences in this property possibly explain the pattern for water efflux when these snakes are in seawater, which remains to be investigated.

Minoxidil Skin Delivery from Nanoemulsion Formulations Containing Eucalyptol or Oleic Acid: Enhanced Diffusivity and Follicular Targeting

Science.gov (United States)

Abd, Eman; Benson, Heather A. E.; Roberts, Michael S.; Grice, Jeffrey E.

2018-01-01

In this work, we examined enhanced skin delivery of minoxidil applied in nanoemulsions incorporating skin penetration enhancers. Aliquots of fully characterized oil-in-water nanoemulsions (1 mL), containing minoxidil (2%) and the skin penetration enhancer oleic acid or eucalyptol as oil phases, were applied to full-thickness excised human skin in Franz diffusion cells, while aqueous solutions (1 mL) containing minoxidil were used as controls. Minoxidil in the stratum corneum (SC), hair follicles, deeper skin layers, and flux through the skin over 24 h was determined, as well as minoxidil solubility in the formulations and in the SC. The nanoemulsions significantly enhanced the permeation of minoxidil through skin compared with control solutions. The eucalyptol formulations (NE) promoted minoxidil retention in the SC and deeper skin layers more than did the oleic acid formulations, while the oleic acid formulations (NO) gave the greatest hair follicle penetration. Minoxidil maximum flux enhancement was associated with increases in both minoxidil SC solubility and skin diffusivity in both nanoemulsion systems. The mechanism of enhancement appeared to be driven largely by increased diffusivity, rather than increased partitioning into the stratum corneum, supporting the concept of enhanced fluidity and disruption of stratum corneum lipids. PMID:29370122

Minoxidil Skin Delivery from Nanoemulsion Formulations Containing Eucalyptol or Oleic Acid: Enhanced Diffusivity and Follicular Targeting

Directory of Open Access Journals (Sweden)

Eman Abd

2018-01-01

Full Text Available In this work, we examined enhanced skin delivery of minoxidil applied in nanoemulsions incorporating skin penetration enhancers. Aliquots of fully characterized oil-in-water nanoemulsions (1 mL, containing minoxidil (2% and the skin penetration enhancer oleic acid or eucalyptol as oil phases, were applied to full-thickness excised human skin in Franz diffusion cells, while aqueous solutions (1 mL containing minoxidil were used as controls. Minoxidil in the stratum corneum (SC, hair follicles, deeper skin layers, and flux through the skin over 24 h was determined, as well as minoxidil solubility in the formulations and in the SC. The nanoemulsions significantly enhanced the permeation of minoxidil through skin compared with control solutions. The eucalyptol formulations (NE promoted minoxidil retention in the SC and deeper skin layers more than did the oleic acid formulations, while the oleic acid formulations (NO gave the greatest hair follicle penetration. Minoxidil maximum flux enhancement was associated with increases in both minoxidil SC solubility and skin diffusivity in both nanoemulsion systems. The mechanism of enhancement appeared to be driven largely by increased diffusivity, rather than increased partitioning into the stratum corneum, supporting the concept of enhanced fluidity and disruption of stratum corneum lipids.

Topical bioavailability of diclofenac from locally-acting, dermatological formulations.

Science.gov (United States)

Cordery, S F; Pensado, A; Chiu, W S; Shehab, M Z; Bunge, A L; Delgado-Charro, M B; Guy, R H

2017-08-30

Assessment of the bioavailability of topically applied drugs designed to act within or beneath the skin is a challenging objective. A number of different, but potentially complementary, techniques are under evaluation. The objective of this work was to evaluate in vitro skin penetration and stratum corneum tape-stripping in vivo as tools with which to measure topical diclofenac bioavailability from three approved and commercialized products (two gels and one solution). Drug uptake into, and its subsequent clearance from, the stratum corneum of human volunteers was used to estimate the input rate of diclofenac into the viable skin layers. This flux was compared to that measured across excised porcine skin in conventional diffusion cells. Both techniques clearly demonstrated (a) the superiority in terms of drug delivery from the solution, and (b) that the two gels performed similarly. There was qualitative and, importantly, quantitative agreement between the in vitro and in vivo measurements of drug flux into and beyond the viable skin. Evidence is therefore presented to support an in vivo - in vitro correlation between methods to assess topical drug bioavailability. The potential value of the stratum corneum tape-stripping technique to quantify drug delivery into (epi)dermal and subcutaneous tissue beneath the barrier is demonstrated. Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical peeling by SA-PEG remodels photo-damaged skin: suppressing p53 expression and normalizing keratinocyte differentiation.

Science.gov (United States)

Dainichi, Teruki; Amano, Satoshi; Matsunaga, Yukiko; Iriyama, Shunsuke; Hirao, Tetsuji; Hariya, Takeshi; Hibino, Toshihiko; Katagiri, Chika; Takahashi, Motoji; Ueda, Setsuko; Furue, Masutaka

2006-02-01

Chemical peeling with salicylic acid in polyethylene glycol vehicle (SA-PEG), which specifically acts on the stratum corneum, suppresses the development of skin tumors in UVB-irradiated hairless mice. To elucidate the mechanism through which chemical peeling with SA-PEG suppresses skin tumor development, the effects of chemical peeling on photodamaged keratinocytes and cornified envelopes (CEs) were evaluated in vivo. Among UVB-irradiated hairless mice, the structural atypia and expression of p53 protein in keratinocytes induced by UVB irradiation were intensely suppressed in the SA-PEG-treated mice 28 days after the start of weekly SA-PEG treatments when compared to that in the control UVB-irradiated mice. Incomplete expression of filaggrin and loricrin in keratinocytes from the control mice was also improved in keratinocytes from the SA-PEG-treated mice. In photo-exposed human facial skin, immature CEs were replaced with mature CEs 4 weeks after treatment with SA-PEG. Restoration of photodamaged stratum corneum by treatment with SA-PEG, which may affect remodeling of the structural environment of the keratinocytes, involved the normalization of keratinocyte differentiation and suppression of skin tumor development. These results suggest that the stratum corneum plays a protective role against carcinogenesis, and provide a novel strategy for the prevention of photo-induced skin tumors.

Interaction of lipid nanoparticles with human epidermis and an organotypic cell culture model

DEFF Research Database (Denmark)

Kuntsche, Judith; Bunjes, Heike; Fahr, Alfred

2008-01-01

Various lipid nanoparticle formulations were investigated with respect to (trans)dermal drug delivery with special regard to the mechanism of their effects on human and an organotypic cell culture epidermis. Potential alterations of stratum corneum lipid domains were studied using fluorescence...... assays with labeled liposomes and thermal analysis of isolated stratum corneum. Influences on the permeation of corticosterone were investigated and the occlusive properties of the nanoparticles were determined by measurements of the transepidermal water loss (TEWL). The penetration of a fluorescence dye...... studies and thermal analysis of human and cell culture epidermis indicate that surface lipids, which are not present to the same extent in the cell culture model than in human epidermis, seem to play an important role....

Preparation and evaluation of microemulsion-based transdermal delivery of total flavone of rhizoma arisaematis

Directory of Open Access Journals (Sweden)

Shen LN

2014-07-01

Full Text Available Li-Na Shen,1 Yong-Tai Zhang,1 Qin Wang,2 Ling Xu,2 Nian-Ping Feng11Department of Pharmaceutical Sciences, 2Department of Oncology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of ChinaAbstract: The aims of the present study were to investigate the skin permeation and cellular uptake of a microemulsion (ME containing total flavone of rhizoma arisaematis (TFRA, and to evaluate its effects on skin structure. Pseudo-ternary phase diagrams were constructed to evaluate ME regions with various surfactants and cosurfactants. Eight formulations of ­oil-in-water MEs were selected as vehicles, and in vitro skin-permeation experiments were performed to optimize the ME formulation and to evaluate its permeability, in comparison to that of an aqueous suspension. Laser scanning confocal microscopy and fluorescent-activated cell sorting were used to explore the cellular uptake of rhodamine 110-labeled ME in human epidermal keratinocytes (HaCaT and human embryonic skin fibroblasts (CCC-ESF-1. The structure of stratum corneum treated with ME was observed using a scanning electron microscope. Furthermore, skin irritation was tested to evaluate the safety of ME. ME formulated with 4% ethyl oleate (weight/weight, 18% Cremophor EL® (weight/weight, and 18% Transcutol® P, with 1% Azone to enhance permeation, showed good skin permeability. ME-associated transdermal fluxes of schaftoside and isoschaftoside, two major effective constituents of TFRA, were 3.72-fold and 5.92-fold higher, respectively, than those achieved using aqueous suspensions. In contrast, in vitro studies revealed that uptake by HaCaT and CCC-ESF-1 cells was lower with ME than with an aqueous suspension. Stratum corneum loosening and shedding was observed in nude mouse skin treated with ME, although ME produced no observable skin irritation in rabbits. These findings indicated that ME enhanced transdermal TFRA delivery effectively and showed

Enhanced transdermal delivery with less irritation by magainin pore-forming peptide with a N-lauroylsarcosine and sorbitan monolaurate mixture.

Science.gov (United States)

Lee, Haerin; Park, Juhyun; Kim, Yeu-Chun

2018-02-01

Transdermal drug delivery is advantageous over other conventional drug administration routes. However, it can be inefficient because of the natural barrier of the stratum corneum which is the uppermost layer of the skin. A previous study verified that the treatment of magainin pore-forming peptide with N-lauroylsarcosine (NLS) on human skin can increase skin permeability by 47-fold. However, NLS is well known as a potential skin irritant. The irritation potential of NLS is known to decrease when mixed with sorbitan monolaurate (S20). Encouraged by these results, we combined S20 with magainin-NLS to enhance transdermal drug transport with less skin irritation. In this study, nine groups with magainin and NLS:S20 mixtures at different concentrations and weight fractions were screened to maximize their synergistic effect. To quantify the efficacy to toxicity ratio of each formulation, we defined the ratio as the "enhancement ratio/irritation potential (ER/IP)." The ER was observed by Franz cell diffusion of the target drug fluorescein, and the IP was measured by the cytotoxicity of the NIH/3T3 mouse fibroblast cell line. As a result, the magainin with the NLS:S20 mixture increased the permeability of porcine skin as well as decreased the toxicity. Among the various combinations, a formulation of 2% (w/v) NLS:S20 with a weight fraction of 0.6:0.4 had the largest ER/IP. ATR-FTIR spectroscopy of the formulations and skin was done to analyze the interactions in the formulations themselves and between the formulations and the skin. Both the intercellular lipidic route and transcellular route through the stratum corneum protein were involved in the delivery of fluorescein. This study turned pore-forming peptides into an efficient and safe penetration enhancer by combining them with other chemical penetration enhancers. Moreover, this discovery could be a possible method for enabling the transdermal delivery of macromolecules.

The integration of physiologically-targeted skin care in the management of atopic dermatitis: focus on the use of a cleanser and moisturizer system incorporating a ceramide precursor, filaggrin degradation products, and specific "skin-barrier-friendly" excipients.

Science.gov (United States)

Del Rosso, James Q; Kircik, Leon H

2013-07-01

Atopic dermatitis (AD) may be considered the "poster disease" for exemplifying the significance of abnormalities of the epidermal barrier that occur predominantly within the stratum corneum (SC) and upper epidermis. Specifically, impairments of the SC permeability barrier, antimicrobial barrier, and immunologic barrier contribute markedly to the fundamental pathophysiology of AD. The multiple clinical sequelae associated with epidermal barrier impairments inherent to AD include dry skin, pruritus, increased skin sensitivity to irritants and allergens, eczematous skin changes, staphylococcal skin and anterior nares colonization, and increase in some cutaneous infections (ie, molluscum contagiosum). This article addresses the pathophysiology of AD with clinically relevant correlations, and discusses the scientific basis of a specially designed cleanser and moisturizer system that incorporates ceramide technology and filaggrin degradation products along with other "barrier-friendly" excipients.

Transdermal permeation of geniposide in the herbal complex liniment in vivo and in vitro.

Science.gov (United States)

Wang, Yugang; Li, Lele; Li, Huiying; Zhu, Zhaoyun; Hua, Lei; Lei, Fan; Kheir, Michael M; Du, Lijun

2010-06-15

Zhongtong Caji, a kind of liniment, is a traditional Chinese medicinal formula that is widely used for clinical treatment of inflammation and sprains. In this study, the principal effective compound of this formula, geniposide, was used as a criterion to represent the transdermal permeability of the whole formula. A passive diffusion of Zhongtong Caji through the stratum corneum was discovered by an in vitro experiment. The dosage-content relationship detected in subcutaneous tissue after in vivo drug administration was further evidence of its permeation. Blood analysis after different dosages showed that the geniposide could be absorbed and accumulated by subcutaneous tissue within 1h after drug administration, and it would be eliminated by blood circulation 1h after drug treatment. Copyright 2010 Elsevier B.V. All rights reserved.

A Hydrogel/Carbon-Nanotube Needle-Free Device for Electrostimulated Skin Drug Delivery.

Science.gov (United States)

Guillet, Jean-François; Flahaut, Emmanuel; Golzio, Muriel

2017-10-06

The permeability of skin allows passive diffusion across the epidermis to reach blood vessels but this is possible only for small molecules such as nicotine. In order to achieve transdermal delivery of large molecules such as insulin or plasmid DNA, permeability of the skin and mainly the permeability of the stratum corneum skin layer has to be increased. Moreover, alternative routes that avoid the use of needles will improve the quality of life of patients. A method known as electropermeabilisation has been shown to increase skin permeability. Herein, we report the fabrication of an innovative hydrogel made of a nanocomposite material. This nanocomposite device aims to permeabilise the skin and deliver drug molecules at the same time. It includes a biocompatible polymer matrix (hydrogel) and double-walled carbon nanotubes (DWCNTs) in order to bring electrical conductivity and improve mechanical properties. Carbon nanotubes and especially DWCNTs are ideal candidates, combining high electrical conductivity with a very high specific surface area together with a good biocompatibility when included into a material. The preparation and characterization of the nanocomposite hydrogel as well as first results of electrostimulated transdermal delivery using an ex vivo mouse skin model are presented. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aspen Forest Cover by Stratum/Plot (SNF)

Data.gov (United States)

National Aeronautics and Space Administration — Average percent coverage and standard deviation of each canopy stratum from subplots at each aspen site during the SNF study in the Superior National Forest, Minnesota

Avaliação da interação de compostos ativos hidratantes com modelo de biomembrana de Crotalus durissus por meio de calorimetria exploratória diferencial e espectroscopia RAMAN

Directory of Open Access Journals (Sweden)

Telma Kaneko

2010-06-01

Full Text Available O objetivo foi verificar as alterações no estrato córneo em modelos alternativos de membrana após a aplicação de ativos hidratantes envolvendo métodos biofísicos. O modelo de biomembrana utilizado foi a muda de pele de Crotalus durissus e os ativos hidratantes foram: uréia, silício orgânico, extrato vegetal de Imperata cylindrica, reação de xilitol e glicose e componentes de NMF. Os resultados da avaliação das alterações do modelo por meio de Espectroscopia Raman com Transformada de Fourier sugerem que os ativos hidratantes confirmam segurança necessária, pois não alteraram de forma acentuada a estrutura do estrato córneo. Utilizando-se Calorimetria Exploratória Diferencial pode-se indicar que a solução de silício orgânico e o gel hidrofílico com uréia apresentaram melhor poder hidratante. Palavras-chave: Estrato córneo. Hidratação. Métodos biofísicos. Crotalus durissus. FT-Raman, DSC. ABSTRACT Study of the interaction of moisturizers with a Crotalus durissus biomembrane by differential scanning calorimetry and RAMAN spectroscopy The objective of this research was to use biophysical techniques to investigate the alterations induced in a biomembrane model of the stratum corneum by the application of moisturizers. The biomembrane was obtained from the skin shed by the rattlesnake Crotalus durissus and the active moisturizing compounds were: urea, dimethylsilanol hyaluronate, Imperata cylindrical plant extract, carbohydrates and natural moisturizing factors (NMF components. Results from FT-Raman spectroscopy suggested that the moisturizers were safe, since they did not promote modifications in the structure of the stratum corneum. Differential scanning calorimetry results indicated that the solution containing the organic silicon compound and the gel with urea showed the best hydrating effects on the stratum corneum. Keywords: Stratum corneum. Hydration. Biophysical techniques. Crotalus durissus. FT-Raman, DSC.

Tight junction regulates epidermal calcium ion gradient and differentiation

International Nuclear Information System (INIS)

Kurasawa, Masumi; Maeda, Tetsuo; Oba, Ai; Yamamoto, Takuya; Sasaki, Hiroyuki

2011-01-01

Research highlights: → We disrupted epidermal tight junction barrier in reconstructed epidermis. → It altered Ca 2+ distribution and consequentially differentiation state as well. → Tight junction should affect epidermal homeostasis by maintaining Ca 2+ gradient. -- Abstract: It is well known that calcium ions (Ca 2+ ) induce keratinocyte differentiation. Ca 2+ distributes to form a vertical gradient that peaks at the stratum granulosum. It is thought that the stratum corneum (SC) forms the Ca 2+ gradient since it is considered the only permeability barrier in the skin. However, the epidermal tight junction (TJ) in the granulosum has recently been suggested to restrict molecular movement to assist the SC as a secondary barrier. The objective of this study was to clarify the contribution of the TJ to Ca 2+ gradient and epidermal differentiation in reconstructed human epidermis. When the epidermal TJ barrier was disrupted by sodium caprate treatment, Ca 2+ flux increased and the gradient changed in ion-capture cytochemistry images. Alterations of ultrastructures and proliferation/differentiation markers revealed that both hyperproliferation and precocious differentiation occurred regionally in the epidermis. These results suggest that the TJ plays a crucial role in maintaining epidermal homeostasis by controlling the Ca 2+ gradient.

Ichthyosis prematurity syndrome: a well-defined congenital ichthyosis subtype

DEFF Research Database (Denmark)

Bygum, Anette; Westermark, Per; Brandrup, Flemming

2008-01-01

Ichthyosis prematurity syndrome is a rare syndrome characterized by the clinical triad of premature birth, thick caseous desquamating epidermis, and neonatal asphyxia. We describe two siblings with ichthyosis prematurity syndrome. The index patient was born at gestational week 34. Immediately aft...... in the stratum corneum and stratum granulosum. Diagnosing this syndrome is important to reassure parents, obstetricians, and pediatricians about its benign course after complications in the perinatal period....

Sodium lauryl sulfate enhances nickel penetration through guinea-pig skin. Studies with energy dispersive X-ray microanalysis

International Nuclear Information System (INIS)

Lindberg, M.; Sagstroem, S.R.; Roomans, G.M.; Forslind, B.

1989-01-01

The effect of sodium lauryl sulphate (SLS), a common ingredient of detergents, on the penetration of nickel through the stratum corneum in the guinea-pig skin model was studied with energy dispersive X-ray microanalysis (EDX) to evaluate the barrier-damaging properties of this common detergent. The EDX technique allows a simultaneous determination of physiologically important elements, e.g., Na, Mg, P, Cl, K, Ca and S in addition to Ni at each point of measurement in epidermal cell strata. Our results show that SLS reduces the barrier function to Ni-ion penetration of the stratum corneum. In addition we have shown that EDX allows analysis of the influence of different factors involved in nickel penetration through the skin by giving data on the physiological effects on the epidermal cells caused by the applied substances

Storage conditions of skin affect tissue structure and in vitro percutaneus penetration

DEFF Research Database (Denmark)

Nielsen, Jesper Bo; Bagatolli, Luis

2016-01-01

skin at -20oC causes structural changes in the upper Stratum Corneum observable with image techniques such as multiphoton excitation fluorescence microscopy. The presently available literature does, however, not support that the observed structural damage to the integrity is sufficient to cause...... structural changes in upper as well as deeper parts of Stratum Corneum. These more severe changes corresponds to significantly increased percutaneous penetration of chemicals applied to skin specimens stored at very low temperatures. Storage of human skin for later use in in vitro studies on percutaneous......For logistic and practical reasons it is difficult to perform in vitro studies on percutaneous penetration on fresh human skin obtained directly from surgery. Skin samples are therefore often kept frozen until use. The present chapter present the available literature on the topic. Storage of human...

Measurement, analysis and prediction of topical UV filter bioavailability.

Science.gov (United States)

Roussel, L; Gilbert, E; Salmon, D; Serre, C; Gabard, B; Haftek, M; Maibach, H I; Pirot, F

2015-01-30

The aim of the present study was to objectively quantify and predict bioavailability of three sunscreen agents (i.e., benzophenone-3, 2-ethylhexylsalicylate, and 2 ethylhexyl-4-methoxycinnamate) in epidermis treated by petrolatum and emulsion-based formulations for 7 and 30min on four human volunteers. Profiles of sunscreen agents through stratum corneum (SC), derived from the assessment of chemical amounts in SC layers collected by successive adhesive tape-stripping, were successfully fitted to Fick's second law of diffusion. Therefore, permeability coefficients of sunscreen agents were found lower with petrolatum than with emulsion based formulations confirming the crucial role of vehicle in topical delivery. Furthermore, the robustness of that methodology was confirmed by the linear relationship between the chemical absorption measured after 30min and that predicted from the 7-min exposure experiment. Interestingly, in this dermatopharmacokinetic method, the deconvolution of permeability coefficients in their respective partition coefficients and absorption constants allowed a better understanding of vehicle effects upon topical bioavailability mechanisms and bioequivalence of skin products. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluations of imidazolium ionic liquids as novel skin permeation enhancers for drug transdermal delivery.

Science.gov (United States)

Zhang, Ding; Wang, Huai-Ji; Cui, Xiu-Ming; Wang, Cheng-Xiao

2017-06-01

In this work, imidazolium ionic liquids (imidazolium ILs) were employed as the novel chemical permeation enhancers (CPEs) and their performances and mechanisms of action were deeply investigated. Testosterone was used as a model drug to investigate the transdermal delivery enhancement of twenty imdidazolium ILs. The results suggested that the promotion activity connected to the structure and composition of the ILs. The quantitative structure-activity relationship (QSAR) model revealed a good linearity between the electronic properties of ILs and their enhancements. Furthermore, the transepidermal water loss (TEWL) and scanning laser confocal microscope (CLSM) examinations showed the strong improvement of ILs on skin barrier permeability, which were well correlated with the drug penetration profiles. The total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscope (AFM) evaluations of skins indicated that the ILs can disrupt the regular and compact arrangements of the corneocytes, change the surface properties of stratum corneum, and make the skin structure more permeable. Our work demonstrated the significant skin permeation promotion profiles of the imidazolium ILs, which are of great potential in transdermal drug delivery systems.

Sarcoptic mange in free-ranging raccoon dogs (Nyctereutes procyonoides) in Japan.

Science.gov (United States)

Ninomiya, Hiroyoshi; Ogata, Munetsugu

2005-06-01

Sarcoptes scabiei infestation was diagnosed in three freshly dead free-ranging raccoon dogs (Nyctereutes procyonoides) in Kanagawa Prefecture, Japan. The dogs presented with an alopecic pruritic skin disease, with signs of alopecia on the ears, muzzle, around the eyes, elbow, thigh and the neck, and hyperpigmented and crusted skin lesions, which had a severe malodour. Skin scrapings revealed the presence of the mite Sarcoptes scabiei. Histopathology of lesions demonstrated marked acanthosis, hyperkeratosis, parakeratosis and fungal elements, which were subsequently identified as Acremonium sp., Alternaria sp. and an unknown fungus. Mite segments were located mainly in the stratum corneum and also in the stratum granulosum. Tunnels could be observed in the hyperkeratotic stratum corneum. Scanning electron microscopy (SEM) revealed the tortoise-like Sarcoptes scabiei with four long bristles, suckers and blade-like claws on legs 1 and 2, cuticular spines, prominent body striations and a terminal anus. SEM also revealed an adult female mite digging a tunnel with the head wedged into the very end of the closed burrow. Tunnels filled with eggshells, corneocyte debris and faecal pellets were also observed.

Elucidation of the Synthetic Mechanism of Acylceramide, an Essential Lipid for Skin Barrier Function.

Science.gov (United States)

Ohno, Yusuke

2017-01-01

The primary function of the skin is to act as a permeability barrier that prevents water loss from inside the body and external invasion such as by pathogens, harmful substances, and allergens. Lipids play a critical role in skin barrier formation by forming multi-lamellar structures in the stratum corneum, the outermost cell layer of the epidermis. Ceramide, the backbone of sphingolipids, accounts for more than 50% of the stratum corneum lipids. Acylceramides are epidermis-specific ceramide species essential for skin barrier formation. Decreases in acylceramide levels and changes in ceramide composition and chain-length are associated with such cutaneous disorders as ichthyosis, atopic dermatitis, and psoriasis. Acylceramide consists of a long-chain base and an amide-linked ultra-long-chain fatty acid (ULCFA, 28-36 carbon chain), which is ω-hydroxylated and esterified with linoleic acid. Although the molecular mechanism by which acylceramide is generated has not been fully understood for decades, we recently identified two genes, CYP4F22 and PNPLA1, involved in acylceramide synthesis and elucidated the entire biosynthetic pathway of acylceramide: the synthesis of ULCFA by ELOVL1 and ELOVL4, ω-hydroxylation of the ULCFA by CYP4F22, amide-bond formation with a long-chain base by CERS3, and transacylation of linoleic acid from triacylglycerol to ω-hydroxyceramide by PNPLA1 to generate acylceramide. CYP4F22 and PNPLA1 are the causative genes of ichthyosis. We demonstrated that mutations of CYP4F22 or PNPLA1 markedly reduced acylceramide production. Our recent findings provide important insights into the molecular mechanisms of skin barrier formation and of ichthyosis pathogenesis.

Microspectroscopic Confocal Raman and Macroscopic Biophysical Measurements in the in vivo Assessment of the Skin Barrier: Perspective for Dermatology and Cosmetic Sciences

NARCIS (Netherlands)

Falcone, D.; Uzunbajakava, N.E.; Varghese, B.; Aquino Santos, G.R. de; Richters, R.J.H.; Kerkhof, P.C.M. van de; Erp, P.E.J. van

2015-01-01

Skin barrier function, confined to the stratum corneum, is traditionally evaluated using established, noninvasive biophysical methods like transepidermal water loss, capacitance and conductance. However, these methods neither measure skin molecular composition nor its structure, hindering the actual

Investigating the sonophoresis effect on the permeation of diclofenac sodium using 3D skin equivalent.

Science.gov (United States)

Aldwaikat, Mai; Alarjah, Mohammed

2015-01-01

Ultrasound temporally increases skin permeability by altering stratum corneum SC function (sonophoresis). The objective of this study was to evaluate the effect of variable ultrasound conditions on the permeation of diclofenac sodium DS with range of physicochemical properties through EpiDerm™. Permeation studies were carried out in vitro using Franz diffusion cell. HPLC method was used for the determination of the concentration of diclofenac sodium in receiving compartment. Parameters like ultrasound frequency, application time, amplitude, and mode of sonication and distance of ultrasound horn from skin were investigated, and the conditions where the maximum enhancement rate obtained were determined. Application of ultrasound enhanced permeation of diclofenac sodium across EpiDerm™ by fivefolds. The most effective enhancing parameters were power sonication of 20kHz frequency, 20% amplitude at continuous mode for 5min. Copyright © 2014. Published by Elsevier B.V.

Biomaterials as novel penetration enhancers for transdermal and dermal drug delivery systems.

Science.gov (United States)

Chen, Yang; Wang, Manli; Fang, Liang

2013-01-01

The highly organized structure of the stratum corneum provides an effective barrier to the drug delivery into or across the skin. To overcome this barrier function, penetration enhancers are always used in the transdermal and dermal drug delivery systems. However, the conventional chemical enhancers are often limited by their inability to delivery large and hydrophilic molecules, and few to date have been routinely incorporated into the transdermal formulations due to their incompatibility and local irritation issues. Therefore, there has been a search for the compounds that exhibit broad enhancing activity for more drugs without producing much irritation. More recently, the use of biomaterials has emerged as a novel method to increase the skin permeability. In this paper, we present an overview of the investigations on the feasibility and application of biomaterials as penetration enhancers for transdermal or dermal drug delivery systems.

The effects of esterified solvents on the diffusion of a model compound across human skin: an ATR-FTIR spectroscopic study.

Science.gov (United States)

McAuley, W J; Chavda-Sitaram, S; Mader, K T; Tetteh, J; Lane, M E; Hadgraft, J

2013-04-15

Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy has been used to investigate the effects of three fatty acid esters on skin permeation. Propylene glycol diperlargonate (DPPG), isopropyl myristate (IPM) and isostearyl isostearate (ISIS) were selected as pharmaceutically relevant solvents with a range of lipophilicities and cyanophenol (CNP) was used as a model drug. The resultant data were compared with that obtained when water was used as the solvent. The diffusion of CNP, DPPG and IPM across epidermis was successfully described by a Fickian model. When ISIS was used as a solvent Fickian behaviour was only obtained across isolated stratum corneum suggesting that the hydrophilic layers of the epidermis interfere with the permeation of the hydrophobic ISIS. The diffusion coefficients of CNP across epidermis in the different solvents were not significantly different. Using chemometric data analysis diffusion profiles for the solvents were deconvoluted from that of the skin and modelled. Each of these solvents was found to diffuse at a faster rate across the skin than CNP. DPPG considerably increased the concentration of CNP in the stratum corneum in comparison with the other solvents indicating strong penetration enhancer potential. In contrast IPM produced a similar CNP concentration in the stratum corneum to water with ISIS resulting in a lower CNP concentration suggesting negligible enhancement and penetration retardation effects for these two solvents respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Molecular analysis of ivy cells of the hippocampal CA1 stratum radiatum using spectral identification of immunofluorophores

Directory of Open Access Journals (Sweden)

Jozsef eSomogyi

2012-05-01

Full Text Available Nitric oxide synthase-expressing (NOS+ GABAergic interneurons are common in hippocampal stratum radiatum, but these cells are less well characterised than NOS+ ivy cells in stratum pyramidale or neurogliaform cells in stratum lacunosum-moleculare. Here we have studied the laminar distribution of the axons and dendrites, and the immunoreactivity of these neurons recorded in rat hippocampal slices. We have used spectral analysis of antibody- or streptavidin conjugated fluorophores to improve recognition of genuine signals in reactions for molecules such as NOS and neuropeptide-Y, when immunolabelling was low in the recorded cell. We found that most NOS+ cells with soma in the CA1 area stratum radiatum exhibit characteristic properties of ivy cells; all tested cells were positive for NPY and negative for reelin. However, laminar distributions of their neurites differ from original characterization of ivy cells with the soma close to stratum pyramidale. Both their dendrites and axon are mainly in stratum radiatum and to a lesser extent in stratum oriens. In addition, both the dendrites and axons often extend to stratum lacunosum-moleculare. We conclude that ivy cells in stratum radiatum are predominantly feedforward inhibitory interneurons in the CA1 area, and their axonal output delivering GABA, NPY and NO can influence both the entorhinal cortex innervated and the CA3 innervated zones pre- and postsynaptically. Spectral analysis of fluorophores provides an objective algorithm to analyze signals in immunoreactions for neurochemical markers.

Decreased Sudomotor Function is Involved in the Formation of Atopic Eczema in the Cubital Fossa

Directory of Open Access Journals (Sweden)

Aya Takahashi

2013-01-01

Conclusions: These results suggest that decreased sweating is a major source of water in the stratum corneum, and decreased sudomotor function may be involved in both the cause and aggravation of representative atopic eczema in the cubital fossa.

Management of Patients with Atopic Dermatitis: The Role of Emollient Therapy

Directory of Open Access Journals (Sweden)

M. Catherine Mack Correa

2012-01-01

Full Text Available Atopic dermatitis is a common inflammatory skin disorder that afflicts a growing number of young children. Genetic, immune, and environmental factors interact in a complex fashion to contribute to disease expression. The compromised stratum corneum found in atopic dermatitis leads to skin barrier dysfunction, which results in aggravation of symptoms by aeroallergens, microbes, and other insults. Infants—whose immune system and epidermal barrier are still developing—display a higher frequency of atopic dermatitis. Management of patients with atopic dermatitis includes maintaining optimal skin care, avoiding allergic triggers, and routinely using emollients to maintain a hydrated stratum corneum and to improve barrier function. Flares of atopic dermatitis are often managed with courses of topical corticosteroids or calcineurin inhibitors. This paper discusses the role of emollients in the management of atopic dermatitis, with particular emphasis on infants and young children.

Nickel reactivity and filaggrin null mutations--evaluation of the filaggrin bypass theory in a general population

DEFF Research Database (Denmark)

Ross-Hansen, Katrine; Menné, Torkil; Johansen, Jeanne D

2011-01-01

It was recently shown that filaggrin null mutation carrier status was associated with nickel allergy and self-reported intolerance to costume jewellery. Because of the biochemical characteristics of filaggrin, it may show nickel barrier properties in the stratum corneum....

Transcutaneous immunization using microneedles and cubosomes

DEFF Research Database (Denmark)

Rattanapak, Teerawan; Birchall, James; Young, Katherine

2013-01-01

Transcutaneous (TCI) immunization is a novel vaccination approach that provides many advantages over traditional parenteral vaccination. However, a major barrier to TCI is mediating penetration of vaccine antigens through the stratum corneum (SC) to the deeper tissue layers. Many approaches have...

Variation in the activities of late stage filaggrin processing enzymes, calpain-1 and bleomycin hydrolase, together with pyrrolidone carboxylic acid levels, corneocyte phenotypes and plasmin activities in non-sun-exposed and sun-exposed facial stratum corneum of different ethnicities.

Science.gov (United States)

Raj, N; Voegeli, R; Rawlings, A V; Summers, B; Munday, M R; Lane, M E

2016-12-01

Knowledge of the ethnic differences and effects of photodamage on the relative amounts of natural moisturizing factor (NMF) together with filaggrin processing enzymes in facial stratum corneum is limited. Our aim was to characterize the activities of calpain-1 (C-1), bleomycin hydrolase (BH) and the levels of pyrrolidone carboxylic acid (PCA) as a marker for total NMF levels and to relate them to plasmin activities and corneocyte maturation. Enzyme activities, PCA levels and corneocyte maturation were determined from facial tape strippings of photoexposed cheek and photoprotected post-auricular areas (PA) of healthy Caucasian (C), Black African (BA) and albino African (AA) female subjects living in South Africa. PCA concentration levels were of the order AA > BA > C subjects, and the highest activities of BH were present in the AA subjects. BH activities were greater on the photoexposed sites for the BA and C subjects, but they were only numerically elevated in the AA subjects. Photoprotected sites had an increase in C-1 activity in pigmented groups (C and BA), whereas in the AA subjects, the opposite was measured. Plasmin activities were greater on the cheek compared with the PA site for the AA and C subjects, but the activity was low in the BA subjects. In both test sites, the AA, but not the BA and C subjects, had smaller, parakeratotic and less mature corneocytes. Variation in PCA levels has been found for different ethnic groups in this study (AA > BA > C subjects). The values in the AA subjects are surprising as one might expect that the lack of pigmentation, and thereby increased photodamage, might lead to lower levels. Increased BH, but not C-1 activity, was observed in the AA subjects indicating that BH is associated with PCA production to a greater extent. Surprisingly, corneocyte maturation is still impaired with elevated PCA levels in AA subjects. The higher levels of plasmin and BH activities on the cheeks, especially for AA and C subjects, suggest

Solar radiation (PAR and UVA) and water temperature in relation to biochemical performance of Gelidium corneum (Gelidiales, Rhodophyta) in subtidal bottoms off the Basque coast

Science.gov (United States)

Quintano, Endika; Ganzedo, Unai; Díez, Isabel; Figueroa, Félix L.; Gorostiaga, José M.

2013-10-01

Gelidium corneum (Hudson) J.V. Lamouroux is a very important primary producer in the Cantabrian coastal ecosystem. Some local declines in their populations have been recently detected in the Basque coast. Occurrences of yellowing and an unusual branch breakdown pattern have also been reported for some G. corneum populations. In order to gain further insight into those environmental stressors operating at a local scale, here we investigate if shallow subtidal populations of G. corneum living under potentially different conditions of irradiance (PAR and UVA) and water temperature exhibit differences in some biochemical indicators of stress, namely C:N, antioxidant activity (radical cation of 2,2‧-azino-bis (3-ethylbenzothiazoline-6-sulfonate); ABTS+ assay) and mycosporine-like amino acids (MAAs) (Asterine 330 and Palythine). We hypothesised that G. corneum subjected to higher ambient levels of irradiance and water temperature would show higher C:N ratios, lower antioxidant activity and higher MAA concentrations. Our results partially support this hypothesis. We found that G. corneum exposed to increased levels of irradiance (PAR, UVA) exhibited greater C:N ratios and lower antioxidant activity (higher IC50), whereas no relationship was found regarding MAAs. No differences in biochemical performance in relation to temperature were detected among G. corneum exposed to comparable high light. Similarly, G. corneum growing under lower UVA radiation levels showed no differences in any of the measured biochemical variables with regard to PAR and water temperature. These findings suggest that, among the environmental factors examined, UVA radiation may be an important driver in regulating the along-shore variation in G. corneum biochemical performance. Therefore, the role of irradiance, especially UV radiation, in potential future alterations in Cantabrian G. corneum populations cannot be ruled out as a potential underlying factor.

Nanoporous Microneedle Arrays Effectively Induce Antibody Responses against Diphtheria and Tetanus Toxoid

NARCIS (Netherlands)

de Groot, Anne Marit; Platteel, Anouk C M; Kuijt, Nico; van Kooten, Peter J S; Vos, Pieter Jan; Sijts, Alice J A M; van der Maaden, Koen

2017-01-01

The skin is immunologically very potent because of the high number of antigen-presenting cells in the dermis and epidermis, and is therefore considered to be very suitable for vaccination. However, the skin's physical barrier, the stratum corneum, prevents foreign substances, including vaccines,

Simulations of Skin Barrier Function: Free Energies of Hydrophobic and Hydrophilic Transmembrane Pores in Ceramide Bilayers

NARCIS (Netherlands)

Notman, Rebecca; Anwar, Jamshed; Briels, Willem J.; Noro, Massimo G.; den Otter, Wouter K.

2008-01-01

Transmembrane pore formation is central to many biological processes such as ion transport, cell fusion, and viral infection. Furthermore, pore formation in the ceramide bilayers of the stratum corneum may be an important mechanism by which penetration enhancers such as dimethylsulfoxide (DMSO)

Heat: A Highly Efficient Skin Enhancer for Transdermal Drug Delivery.

Science.gov (United States)

Szunerits, Sabine; Boukherroub, Rabah

2018-01-01

Advances in materials science and bionanotechnology have allowed the refinements of current drug delivery systems, expected to facilitate the development of personalized medicine. While dermatological topical pharmaceutical formulations such as foams, creams, lotions, gels, etc., have been proposed for decades, these systems target mainly skin-based diseases. To treat systemic medical conditions as well as localized problems such as joint or muscle concerns, transdermal delivery systems (TDDSs), which use the skin as the main route of drug delivery, are very appealing. Over the years, these systems have shown to offer important advantages over oral as well as intravenous drug delivery routes. Besides being non-invasive and painless, TDDSs are able to deliver drugs with a short-half-life time more easily and are well adapted to eliminate frequent administrations to maintain constant drug delivery. The possibility of self-administration of a predetermined drug dose at defined time intervals makes it also the most convenient personalized point-of-care approach. The transdermal market still remains limited to a narrow range of drugs. While small and lipophilic drugs have been successfully delivered using TDDSs, this approach fails to deliver therapeutic macromolecules due to size-limited transport across the stratum corneum , the outermost layer of the epidermis. The low permeability of the stratum corneum to water-soluble drugs as well as macromolecules poses important challenges to transdermal administration. To widen the scope of drugs for transdermal delivery, new procedures to enhance skin permeation to hydrophilic drugs and macromolecules are under development. Next to iontophoresis and microneedle-based concepts, thermal-based approaches have shown great promise to enhance transdermal drug delivery of different therapeutics. In this inaugural article for the section "Frontiers in Bioengineering and Biotechnology," the advances in this field and the handful of

Topical Nano and Microemulsions for Skin Delivery

Directory of Open Access Journals (Sweden)

Christofori M. R. R. Nastiti

2017-09-01

Full Text Available Nanosystems such as microemulsions (ME and nanoemulsions (NE offer considerable opportunities for targeted drug delivery to and via the skin. ME and NE are stable colloidal systems composed of oil and water, stabilised by a mixture of surfactants and cosurfactants, that have received particular interest as topical skin delivery systems. There is considerable scope to manipulate the formulation components and characteristics to achieve optimal bioavailability and minimal skin irritancy. This includes the incorporation of established chemical penetration enhancers to fluidize the stratum corneum lipid bilayers, thus reducing the primary skin barrier and increasing permeation. This review discusses nanosystems with utility in skin delivery and focuses on the composition and characterization of ME and NE for topical and transdermal delivery. The mechanism of skin delivery across the stratum corneum and via hair follicles is reviewed with particular focus on the influence of formulation.

Acral peeling skin syndrome in two East-African siblings: case report

OpenAIRE

Kiprono, Samson K; Chaula, Baraka M; Naafs, Bernard; Masenga, John E

2012-01-01

Abstract Background Acral peeling skin syndrome is a rare autosomal recessive genodermatosis due to a missense mutation in transglutaminase 5. The skin peeling occurs at the separation of the stratum corneum from the stratum granulosum. Case presentation We present a case of two siblings who developed continuous peeling of the palms and soles from the first year of life. This peeling was more severe on the soles than palms and on younger sibling than elder sibling. Peeling is worsened by occl...

Early-life risk factors for occurrence of atopic dermatitis during the first year.

Science.gov (United States)

Sugiyama, Mikio; Arakawa, Hirokazu; Ozawa, Kiyoshi; Mizuno, Takahisa; Mochizuki, Hiroyuki; Tokuyama, Kenichi; Morikawa, Akihiro

2007-03-01

In a prospective birth cohort study, we sought to identify perinatal predictors of the occurrence of atopic dermatitis in the first year of life. Associations of family history, infection during pregnancy, cord blood cytokine concentrations, and skin function parameters with atopic dermatitis were analyzed. Stratum corneum hydration was measured with an impedance meter until 5 days after delivery and again at 1 month. Complete data were obtained for 213 infants, including 27 diagnosed by a physician as having atopic dermatitis during their first year and 26 diagnosed as having infantile eczema during their first month. The risk of atopic dermatitis during the first year of life was related to maternal atopic dermatitis, lower concentrations of macrophage inflammatory protein-1beta in cord blood, and greater skin moisture in the surface and stratum corneum of the forehead and cheek at 1 month of age but not to viral or bacterial infection during pregnancy or breastfeeding. Paternal hay fever was associated negatively with the development of atopic dermatitis. High concentrations of interleukin-5, interleukin-17, and macrophage chemotactic protein-1 and only surface moisture in the cheek were associated with greater risk of infantile eczema in the first month. The association of atopic dermatitis in infancy with reduced neonatal macrophage inflammatory protein-1beta levels suggests a link with immature immune responses at birth. Stratum corneum barrier disruption in atopic dermatitis may involve impairment of cutaneous adaptation to extrauterine life. The majority of risk factors had different effects on infant eczema and atopic dermatitis, indicating different causes.

Effect of olive and sunflower seed oil on the adult skin barrier: implications for neonatal skin care.

Science.gov (United States)

Danby, Simon G; AlEnezi, Tareq; Sultan, Amani; Lavender, Tina; Chittock, John; Brown, Kirsty; Cork, Michael J

2013-01-01

Natural oils are advocated and used throughout the world as part of neonatal skin care, but there is an absence of evidence to support this practice. The goal of the current study was to ascertain the effect of olive oil and sunflower seed oil on the biophysical properties of the skin. Nineteen adult volunteers with and without a history of atopic dermatitis were recruited into two randomized forearm-controlled mechanistic studies. The first cohort applied six drops of olive oil to one forearm twice daily for 5 weeks. The second cohort applied six drops of olive oil to one forearm and six drops of sunflower seed oil to the other twice daily for 4 weeks. The effect of the treatments was evaluated by determining stratum corneum integrity and cohesion, intercorneocyte cohesion, moisturization, skin-surface pH, and erythema. Topical application of olive oil for 4 weeks caused a significant reduction in stratum corneum integrity and induced mild erythema in volunteers with and without a history of atopic dermatitis. Sunflower seed oil preserved stratum corneum integrity, did not cause erythema, and improved hydration in the same volunteers. In contrast to sunflower seed oil, topical treatment with olive oil significantly damages the skin barrier, and therefore has the potential to promote the development of, and exacerbate existing, atopic dermatitis. The use of olive oil for the treatment of dry skin and infant massage should therefore be discouraged. These findings challenge the unfounded belief that all natural oils are beneficial for the skin and highlight the need for further research. © 2012 Wiley Periodicals, Inc.

From Cell to Tissue Properties-Modeling Skin Electroporation With Pore and Local Transport Region Formation.

Science.gov (United States)

Dermol-Cerne, Janja; Miklavcic, Damijan

2018-02-01

Current models of tissue electroporation either describe tissue with its bulk properties or include cell level properties, but model only a few cells of simple shapes in low-volume fractions or are in two dimensions. We constructed a three-dimensional model of realistically shaped cells in realistic volume fractions. By using a 'unit cell' model, the equivalent dielectric properties of whole tissue could be calculated. We calculated the dielectric properties of electroporated skin. We modeled electroporation of single cells by pore formation on keratinocytes and on the papillary dermis which gave dielectric properties of the electroporated epidermis and papillary dermis. During skin electroporation, local transport regions are formed in the stratum corneum. We modeled local transport regions and increase in their radii or density which affected the dielectric properties of the stratum corneum. The final model of skin electroporation accurately describes measured electric current and voltage drop on the skin during electroporation with long low-voltage pulses. The model also accurately describes voltage drop on the skin during electroporation with short high-voltage pulses. However, our results indicate that during application of short high-voltage pulses additional processes may occur which increase the electric current. Our model connects the processes occurring at the level of cell membranes (pore formation), at the level of a skin layer (formation of local transport region in the stratum corneum) with the tissue (skin layers) and even level of organs (skin). Using a similar approach, electroporation of any tissue can be modeled, if the morphology of the tissue is known.

Electrospun polymeric nanofibers for transdermal drug delivery

Directory of Open Access Journals (Sweden)

Mahya Rahmani

2017-04-01

Full Text Available Conventional transdermal drug delivery systems (TDDS have been designed for drug delivery through the skin. These systems use the permeability property of stratum corneum, the outermost surface layer of the skin. Applying polymeric micro and nanofibers in drug delivery has recently attracted great attention and the electrospinning technique is the preferred method for polymeric micro-nanofibers fabrication with a great potential for drug delivery. More studies in the field of nanofibers containing drug are divided two categories: first, preparation and characterization of nanofibers containing drug and second, investigation of their therapeutic applications. Drugs used in electrospun nanofibers can be categorized into three main groups, including antibiotics and antimicrobial agents, anti-inflammatory agents and vitamins with therapeutic applications. In this paper, we review the application of electrospun polymeric scaffolds in TDDS and also introduce several pharmaceutical and therapeutic agents which have been used in polymer nanofibrous patches.

Effect of allergens and irritants on levels of natural moisturizing factor and corneocyte morphology

NARCIS (Netherlands)

Koppes, Sjors A.; Ljubojević Hadžavdić, Suzana; Jakasa, Ivone; Franceschi, Nika; Riethmüller, Christoph; Jurakić Tončic, Ružica; Marinovic, Branka; Raj, Nidhin; Rawlings, Anthony V.; Voegeli, Rainer; Lane, Majella E.; Haftek, Marek; Frings-Dresen, Monique H. W.; Rustemeyer, Thomas; Kezic, Sanja

2017-01-01

The irritant sodium lauryl sulfate (SLS) is known to cause a decrease in the stratum corneum level of natural moisturizing factor (NMF), which in itself is associated with changes in corneocyte surface topography. To explore this phenomenon in allergic contact dermatitis. Patch testing was performed

Protective effect of (-)-epigallocatechin gallate on ultraviolet b ...

African Journals Online (AJOL)

... EGCg shows dose-dependent protective effect against UV-B-induced damage on hairless mouse skin. Thus, the plant compound can potentially be used as an alternative agent for photoprotection against UV-B exposure. Keywords: UV-B, Green tea EGCg, Photoprotection, Stratum corneum, Mitochondrion, Melanosome ...

Detection and distribution of endogenous steroids in human stratum corneum

Directory of Open Access Journals (Sweden)

Shu-Ping Tseng

2014-03-01

Conclusion: The results demonstrate that, with the achievable sensitivity of current analytical technology, physiological concentrations of endogenous steroids, such as hydrocortisone and cortisone, can be found in the SC of some individuals.

Bed structure (frond bleaching, density and biomass) of the red alga Gelidium corneum under different irradiance levels

Science.gov (United States)

Quintano, E.; Díez, I.; Muguerza, N.; Figueroa, F. L.; Gorostiaga, J. M.

2017-12-01

In recent decades a decline in the foundation species Gelidium corneum (Hudson) J. V. Lamouroux has been detected along the Basque coast (northern Spain). This decline has been attributed to several factors, but recent studies have found a relationship between high irradiance and the biochemical and physiological stress of G. corneum. Since physiological responses to changes in light occur well before variations in morphology, the present study seeks to use a size-class demographic approach to investigate whether shallow subtidal populations of G. corneum off the Basque coast show different frond bleaching, density and biomass under different irradiance conditions. The results revealed that the bleaching incidence and cover were positively related to irradiance, whereas biomass was negatively related. The effect of the irradiance level on frond density was found to vary with size-class, i.e. fronds up to 15 cm showed greater densities under high light conditions (126.6 to 262.2 W m- 2) whereas the number of larger fronds (> 20 cm) per unit area was lower. In conclusion, the results of the present study suggest that irradiance might be a key factor for controlling along-shore bleaching, frond density and biomass in G. corneum. Further research should be carried out on the physiology of this canopy species in relation to its bed structure and on the interaction of irradiance and other abiotic (nutrients, temperature, wave energy) and biotic factors (grazing pressure).

Performance evaluation of multi-stratum resources integrated resilience for software defined inter-data center interconnect.

Science.gov (United States)

Yang, Hui; Zhang, Jie; Zhao, Yongli; Ji, Yuefeng; Wu, Jialin; Lin, Yi; Han, Jianrui; Lee, Young

2015-05-18

Inter-data center interconnect with IP over elastic optical network (EON) is a promising scenario to meet the high burstiness and high-bandwidth requirements of data center services. In our previous work, we implemented multi-stratum resources integration among IP networks, optical networks and application stratums resources that allows to accommodate data center services. In view of this, this study extends to consider the service resilience in case of edge optical node failure. We propose a novel multi-stratum resources integrated resilience (MSRIR) architecture for the services in software defined inter-data center interconnect based on IP over EON. A global resources integrated resilience (GRIR) algorithm is introduced based on the proposed architecture. The MSRIR can enable cross stratum optimization and provide resilience using the multiple stratums resources, and enhance the data center service resilience responsiveness to the dynamic end-to-end service demands. The overall feasibility and efficiency of the proposed architecture is experimentally verified on the control plane of our OpenFlow-based enhanced SDN (eSDN) testbed. The performance of GRIR algorithm under heavy traffic load scenario is also quantitatively evaluated based on MSRIR architecture in terms of path blocking probability, resilience latency and resource utilization, compared with other resilience algorithms.

Infrared spectroscopic measurement of skin hydration and sebum levels and comparison to corneometer and sebumeter

NARCIS (Netherlands)

Ezerskaia, A.; Pereira, S.F.; Urbach, Paul; Varghese, Babu; Popp, Jürgen; Tuchin, Valery V.; Matthews, Dennis L.; Pavone, Francesco S.

2016-01-01

Skin health characterized by a system of water and lipids in Stratum Corneum provide protection from harmful external elements and prevent trans-epidermal water loss. Skin hydration (moisture) and sebum (skin surface lipids) are considered to be important factors in skin health; a right balance

Analysis of in vivo penetration of textile dyes causing allergic reactions

International Nuclear Information System (INIS)

Lademann, J; Patzelt, A; Worm, M; Richter, H; Sterry, W; Meinke, M

2009-01-01

Contact allergies to textile dyes are common and can cause severe eczema. In the present study, we investigated the penetration of a fluorescent textile dye, dissolved from a black pullover, into the skin of one volunteer during perspiration and nonperspiration. Previously, wearing this pullover had induced a severe contact dermatitis in an 82-year old woman, who was not aware of her sensitization to textile dyes. The investigations were carried out by in vivo laser scanning microscopy. It could be demonstrated that the dye was eluted from the textile material by sweat. Afterwards, the dye penetrated into the stratum corneum and into the hair follicles. Inside the hair follicles, the fluorescent signal was still detectable after 24 h, whereas it was not verifiable anymore in the stratum corneum, Laser scanning microscopy represents an efficient tool for in vivo investigation of the penetration and storage of topically applied substances and allergens into the human skin and reveals useful hints for the development and optimization of protection strategies

Gentle cleansing and moisturizing for patients with atopic dermatitis and sensitive skin.

Science.gov (United States)

Cheong, Wai Kwong

2009-01-01

Atopic dermatitis is a common condition characterized by pruritus, inflammation, and dryness of the skin. Inflammation disrupts the barrier function of the stratum corneum, predisposing the skin to be dry, and increases susceptibility to irritants and secondary bacterial infection. Sensitive skin is common, reported by 40-50% of women and 30% of men in the US, Europe, and Japan. Basic requirements in managing eczema and sensitive skin include effective cleansers that do not compromise skin barrier integrity, alleviation of skin dryness, and restoration of skin barrier function through the use of therapeutic moisturizers. The selection of a skin cleanser is therefore an important part of managing these conditions. Studies have reported clinical improvement with the use of soap-free cleansers in combination with topical treatments. While topical corticosteroids and immunosuppressive agents are mainstays of treatment for atopic dermatitis, therapeutic moisturizers are important adjuncts. Moisturizers improve skin hydration, reduce susceptibility to irritation, restore the integrity of the stratum corneum, and enhance the efficacy of topical corticosteroids.

Terahertz pulse imaging in reflection geometry of human skin cancer and skin tissue

International Nuclear Information System (INIS)

Woodward, Ruth M; Cole, Bryan E; Wallace, Vincent P; Pye, Richard J; Arnone, Donald D; Linfield, Edmund H; Pepper, Michael

2002-01-01

We demonstrate the application of terahertz pulse imaging (TPI) in reflection geometry for the study of skin tissue and related cancers both in vitro and in vivo. The sensitivity of terahertz radiation to polar molecules, such as water, makes TPI suitable for studying the hydration levels in the skin and the determination of the lateral spread of skin cancer pre-operatively. By studying the terahertz pulse shape in the time domain we have been able to differentiate between diseased and normal tissue for the study of basal cell carcinoma (BCC). Basal cell carcinoma has shown a positive terahertz contrast, and inflammation and scar tissue a negative terahertz contrast compared to normal tissue. In vivo measurements on the stratum corneum have enabled visualization of the stratum corneum-epidermis interface and the study of skin hydration levels. These results demonstrate the potential of terahertz pulse imaging for the study of skin tissue and its related disorders, both in vitro and in vivo

Transdermal Delivery of siRNA through Microneedle Array

Science.gov (United States)

Deng, Yan; Chen, Jiao; Zhao, Yi; Yan, Xiaohui; Zhang, Li; Choy, Kwongwai; Hu, Jun; Sant, Himanshu J.; Gale, Bruce K.; Tang, Tao

2016-02-01

Successful development of siRNA therapies has significant potential for the treatment of skin conditions (alopecia, allergic skin diseases, hyperpigmentation, psoriasis, skin cancer, pachyonychia congenital) caused by aberrant gene expression. Although hypodermic needles can be used to effectively deliver siRNA through the stratum corneum, the major challenge is that this approach is painful and the effects are restricted to the injection site. Microneedle arrays may represent a better way to deliver siRNAs across the stratum corneum. In this study, we evaluated for the first time the ability of the solid silicon microneedle array for punching holes to deliver cholesterol-modified housekeeping gene (Gapdh) siRNA to the mouse ear skin. Treating the ear with microneedles showed permeation of siRNA in the skin and could reduce Gapdh gene expression up to 66% in the skin without accumulation in the major organs. The results showed that microneedle arrays could effectively deliver siRNA to relevant regions of the skin noninvasively.

In-vivo dynamic characterization of microneedle skin penetration using optical coherence tomography

Science.gov (United States)

Enfield, Joey; O'Connell, Marie-Louise; Lawlor, Kate; Jonathan, Enock; O'Mahony, Conor; Leahy, Martin

2010-07-01

The use of microneedles as a method of circumventing the barrier properties of the stratum corneum is receiving much attention. Although skin disruption technologies and subsequent transdermal diffusion rates are being extensively studied, no accurate data on depth and closure kinetics of microneedle-induced skin pores are available, primarily due to the cumbersome techniques currently required for skin analysis. We report on the first use of optical coherence tomography technology to image microneedle penetration in real time and in vivo. We show that optical coherence tomography (OCT) can be used to painlessly measure stratum corneum and epidermis thickness, as well as microneedle penetration depth after microneedle insertion. Since OCT is a real-time, in-vivo, nondestructive technique, we also analyze skin healing characteristics and present quantitative data on micropore closure rate. Two locations (the volar forearm and dorsal aspect of the fingertip) have been assessed as suitable candidates for microneedle administration. The results illustrate the applicability of OCT analysis as a tool for microneedle-related skin characterization.

Iron behaviour in the process of stratum-infiltration uranium ore formation

International Nuclear Information System (INIS)

Shmariovich, E.M.; Golubev, V.S.

1980-01-01

Investigated has been the behaviour of iron in the process of stratum infiltration uranium mineralization. Iron is partially avacuated from the forward part of the stratum oxidation zone during the development of infiltration uranium mineralization in pyritiferous rocks. This phenomenon is characterized quantitatively and described on the basis of equations of physical chemistry and dynamics of geochemical processes. Local regions of epigenetic ferruginization caused by opposite diffusion of iron and its precipitation in oxygenous conditions often occur at the sections of sharp moderation of limonitization zone advance. Formation of similar ferruginous margins takes place in a very short geological period (less than thousand years)

The static friction response of non-glabrous skin as a function of surface energy and environmental conditions

NARCIS (Netherlands)

Klaassen, Michel; de Vries, Erik G.; Masen, Marc Arthur

2017-01-01

The (local) environmental conditions have a significant effect on the interaction between skin and products. Plasticisation of the stratum corneum occurs at high humidity, causing this layer to soften and change its surface free energy. In this work we study the effects of the micro-climate on the

Eczema and ceramides: an update

DEFF Research Database (Denmark)

Jungersted, Jakob Mutanu; Agner, Tove

2013-01-01

types of treatment. We also consider the genetic influence on stratum corneum lipids. The review is an update on research indexed in PubMed following the discovery of the filaggrin mutations in atopic dermatitis in 2006, but when newer publications cannot stand alone, we include publications from before...

United States Air Force Summer Faculty Research Program, 1988. Program Technical Report. Volume 4

Science.gov (United States)

1988-12-01

keratin rich regions of the stratum corneum. Evidently the proteins of the RBC are y= unlike keratin! Of more interest to hyoerbaric oxygen. HBO. theraoy ...San Francisco State University. Prooo ed Patient Protocol vs. Conventional HBO Theraoy : Consider a patient requiring HBO for a problem wound on a

Effect of various enhancers on transdermal penetration of indomethacin and urea, and relationship between penetration parameters and enhancement factors.

Science.gov (United States)

Ogiso, T; Iwaki, M; Paku, T

1995-04-01

The enhancing capacity of various chemicals, which are widely recognized as enhancers, for the transdermal penetration into full-thickness rat skin of a model lipophilic drug [indomethacin (IND)] and a hydrophilic permeant (urea) was estimated by an in vitro technique. In addition, the fluidity of the stratum corneum lipids, the partitioning of IND into skin, the lipid (ceramides) extraction from the stratum corneum by enhancers, and the IND solubility in enhancer vehicle were measured and related to the enhancing capacity. In vitro permeation experiments with hairless rat skin unequivocally revealed that the enhancers varied in abilities to enhance the fluxes of both agents. Laurocapram, isopropylmyristate (IPM), sodium oleate, and cineol increased fluxes of both agents to a great extent, but N-methyl-2-pyrrolidone (NMP), N,N-diethyl-m-tolamide (DEET), and oleyl oleate were less effective acclerants. Many enhancers increased the fluidity of the lipids [with a threshold of approximately 0.6-0.8 ns at 37 degrees C in the rotational correlation time (tau c)], the skin partitioning of IND, the extraction of ceramides from the cornified cells, and the thermodynamic activity of IND in vehicle (calculated from the solubility) to varying extents. A good correlation was observed between the increase in the fluidity of stratum corneum lipids and the partitioning of IND into skin, between the increase in the fluidity and the flux or the decrease in lag time for IND, between the removal of ceramides and the skin partitioning of IND, and between the removal of ceramides and the flux of urea (p < 0.05 in all cases).(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of corneocyte structure on the interpretation of permeation profiles of nanoparticles across skin

Energy Technology Data Exchange (ETDEWEB)

Pinheiro, T. [LFI, Instituto Tecnologico Nuclear, and Centro de Fisica Nuclear, Universidade Lisboa E.N. 10, 2685-953 Sacavem (Portugal)]. E-mail: murmur@itn.pt; Pallon, J. [Lund Institute of Technology, Physics Department, Lund University, Lund (Sweden)]. E-mail: Jan.Pallon@pixe.lth.se; Alves, L.C. [LFI, Instituto Tecnologico Nuclear, and Centro de Fisica Nuclear, Universidade Lisboa E.N. 10, 2685-953 Sacavem (Portugal)]. E-mail: lcalves@itn.pt; Verissimo, A. [LFI, Instituto Tecnologico Nuclear, and Centro de Fisica Nuclear, Universidade Lisboa E.N. 10, 2685-953 Sacavem (Portugal)]. E-mail: averissimo@vims.edu; Filipe, P. [Departamento Dermatologia, Hospital Sta. Maria, Lisbon (Portugal)]. E-mail: pfilipe@fm.ul.pt; Silva, J.N. [Departamento Dermatologia, Hospital Sta. Maria, Lisbon (Portugal)]. E-mail: maiasilva@fm.ul.pt; Silva, R. [Departamento Dermatologia, Hospital Sta. Maria, Lisbon (Portugal)]. E-mail: rpalminhas@netcabo.pt

2007-07-15

The permeability of skin to nanoparticles of titanium dioxide (TiO{sub 2}) used in sunscreens as a reflector of the UV wavelengths of sunlight, was examined using nuclear microscopy techniques. Special attention was given to the permeation characteristics of these nanoparticles across the outer layers of skin, the stratum corneum, in healthy and psoriatic skin condition. Aspects that may influence the interpretation of results such as sample preparation difficulties and skin condition were focused. Sample preparation can damage the integrity of the corneocyte layers inducing unwanted artefacts that may bias the evaluation of results. Irradiation conditions may also introduce distortions in the labile structures of human skin. Skin condition, such as loss of corneocyte cohesion occurring in psoriasis also influence the permeation profile of the nanoparticles. Weighing and accounting for these features in the examination of skin by nuclear microscopy is crucial to accurately assess the TiO{sub 2} nanoparticles permeation depth.

Comparison of structure and organization of cutaneous lipids in a reconstructed skin model and human skin: spectroscopic imaging and chromatographic profiling.

Science.gov (United States)

Tfayli, Ali; Bonnier, Franck; Farhane, Zeineb; Libong, Danielle; Byrne, Hugh J; Baillet-Guffroy, Arlette

2014-06-01

The use of animals for scientific research is increasingly restricted by legislation, increasing the demand for human skin models. These constructs present comparable bulk lipid content to human skin. However, their permeability is significantly higher, limiting their applicability as models of barrier function, although the molecular origins of this reduced barrier function remain unclear. This study analyses the stratum corneum (SC) of one such commercially available reconstructed skin model (RSM) compared with human SC by spectroscopic imaging and chromatographic profiling. Total lipid composition was compared by chromatographic analysis (HPLC). Raman spectroscopy was used to evaluate the conformational order, lateral packing and distribution of lipids in the surface and skin/RSM sections. Although HPLC indicates that all SC lipid classes are present, significant differences are observed in ceramide profiles. Raman imaging demonstrated that the RSM lipids are distributed in a non-continuous matrix, providing a better understanding of the limited barrier function. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Atom sharp needles, the missing link in microneedle drug delivery

NARCIS (Netherlands)

Wissink, J.; Berenschot, Johan W.; Tas, Niels Roelof

2008-01-01

The skin barrier function is a major challenge for delivery of drugs via the skin. Located in the outermost layer of the skin, the stratum corneum (SC) consists of dead cells embedded in lipid regions, only 10-20 microm thick, tough but flexible and elastic. Hyperdermic needles penetrate the skin

Assessing The Most Suitable Valuation Approaches And Methodologies For Stratum Title In Malaysia

OpenAIRE

Sr. Faziah Abd Rasid

2015-01-01

The National Land Code (NLC) was amended in 1990 to enable the state authority to issue stratum title for underground space. Stratum Title can be separated from land titles issued for surface land. This is stipulated in Part 5(A) under Section 92A to 92G. According to Section 92G (1), underground land can be used for any purpose provided approval is obtained from the authority, which is the federal government.In relation to underground development with many utilities, the appraisal of real es...

Immunohistochemical demonstration of keratins in the epidermal layers of the Malayan pangolin (Manis javanica, with remarks on the evolution of the integumental scale armour

Directory of Open Access Journals (Sweden)

W. Meyer

2013-09-01

Full Text Available Using immunohistochemistry, the study demonstrates the distribution of keratins (pan-keratin with CK1-8, 10, 14-16, 19; keratins CK1, 5, 6, 9, 10; hair keratins AE13, AE14 in the epidermis of the Malayan pangolin (Manis javanica. A varying reaction spectrum was observed for pan-keratin, with body region-dependent negative to very strong reaction intensities. The dorsolateral epidermis exhibited positive reactions only in its vital layers, whereas the abdominal epidermis showed strong positive reactions in the soft two outer strata. The single acidic and basic-to-neutral (cytokeratins produced clear variations compared to the pan-keratin tinging. E.g., CK1 appeared in all epidermal layers of both body regions, except for the ventral stratum corneum, whereas CK5, 6, 9, 10 were restricted to the soft ventral epidermis. Here, distinctly positive reactions were confined to the stratum granulosum, except for CK6 that appeared in the soft stratum corneum. A different staining pattern was obvious for the hair keratins, i.e., positive reactions of AE13 concentrated only in the granular layer of the dorsal epidermis. In the abdominal epidermis, remarkable tinging for AE14 was visible in the stratum basale, decreasing toward the corneal layer, but was also found in the outer root sheath cells of the hair follicles in the ventral body part. Our findings are discussed related to the evolution of the horny dorsal scales of the pangolin, which may have started from the tail root, projecting forward to the head

Penetration, distribution and kinetics of 2,3,7,8-tetrachlorodibenzo-p-dioxin in human skin in vitro

International Nuclear Information System (INIS)

Weber, L.W.D.; Rozman, K.

1991-01-01

The in vitro penetration of 3 H-labeled 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) into human cadaver skin was studied at concentrations of 65 and 6.5 ng TCDD per cm 2 of skin surface. Vehicles used were acetone to simulate exposure to TCDD as a dry material, and mineral oil to simulate exposure to TCDD in an oily medium. Penetration was performed for 30, 100, 300, and 1000 min in improved Franz cells. Skin was used either intact, or with stripped horny layer. Skin was sectioned along its natural layers and radioactivity determined in epidermis and dermis. TCDD did not readily penetrate into human skin in vitro. The vehicle of exposure to TCDD played an important role in dermal penetration. The rapidly evaporating acetone allowed TCDD to penetrate deeply into the loose surface lamellae of the horny layer, but then appeared to be poorly available for further penetration. Mineral oil as the vehicle showed its penetration even more. The stratum corneum acted as a protective barrier, as its removal increased the amount of TCDD absorbed into layers of the skin. Hourly rates of adsorption of TCDD per unit area of skin were calculated in two ways: a worst case scenario where TCDD absorbed into any layer of skin including the stratum corneum and a physiological approach where only that amount of TCDD was considered absorbed which had penetrated beyond the epidermis. Under worst case scenario conditions the stratum corneum appeared to mediate dermal absorption of TCDD. This was, however, not the case with the physiological approach. There was a consistent relationship between concentration of TCDD applied and concentration of TCDD found in skin. Also, a clear-cut correlation was found between the amount of TCDD that penetrated and the time of exposure. (orig./MG)

The Rheological Properties of Lipid Monolayers Modulate the Incorporation of l-Ascorbic Acid Alkyl Esters.

Science.gov (United States)

Díaz, Yenisleidy de Las Mercedes Zulueta; Mottola, Milagro; Vico, Raquel V; Wilke, Natalia; Fanani, María Laura

2016-01-19

In this work, we tested the hypothesis that the incorporation of amphiphilic drugs into lipid membranes may be regulated by their rheological properties. For this purpose, two members of the l-ascorbic acid alkyl esters family (ASCn) were selected, ASC16 and ASC14, which have different rheological properties when organized at the air/water interface. They are lipophilic forms of vitamin C used in topical pharmacological preparations. The effect of the phase state of the host lipid membranes on ASCn incorporation was explored using Langmuir monolayers. Films of pure lipids with known phase states have been selected, showing liquid-expanded, liquid-condensed, and solid phases as well as pure cholesterol films in liquid-ordered state. We also tested ternary and quaternary mixed films that mimic the properties of cholesterol containing membranes and of the stratum corneum. The compressibility and shear properties of those monolayers were assessed in order to define its phase character. We found that the length of the acyl chain of the ASCn compounds induces differential changes in the rheological properties of the host membrane and subtly regulates the kinetics and extent of the penetration process. The capacity for ASCn uptake was found to depend on the phase state of the host film. The increase in surface pressure resultant after amphiphile incorporation appears to be a function of the capacity of the host membrane to incorporate such amphiphile as well as the rheological response of the film. Hence, monolayers that show a solid phase state responded with a larger surface pressure increase to the incorporation of a comparable amount of amphiphile than liquid-expanded ones. The cholesterol-containing films, including the mixture that mimics stratum corneum, allowed a very scarce ASCn uptake independently of the membrane diffusional properties. This suggests an important contribution of Cho on the maintenance of the barrier function of stratum corneum.

Skin peeling syndrome

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Gharpuray Mohan

1994-01-01

Full Text Available We are reporting a case of skin peeling syndrome, a rare disorder in which sudden generalized exfoliation of the stratum corneum occurs. Histopathologically, there was well formed subcorneal pustule filled with polymorphs and nuclear dust, considering this to be a varient of subcorneal pustular dermatosis, we have put the patient on Dapsone.

Acral peeling skin syndrome in two East-African siblings: case report.

Science.gov (United States)

Kiprono, Samson K; Chaula, Baraka M; Naafs, Bernard; Masenga, John E

2012-03-19

Acral peeling skin syndrome is a rare autosomal recessive genodermatosis due to a missense mutation in transglutaminase 5. The skin peeling occurs at the separation of the stratum corneum from the stratum granulosum. We present a case of two siblings who developed continuous peeling of the palms and soles from the first year of life. This peeling was more severe on the soles than palms and on younger sibling than elder sibling. Peeling is worsened by occlusion and sweating. Sporadic cases of Acral Peeling Skin Syndrome occur in African population. There is variability in time of presentation and clinical severity even within families.

Production and characterization of cosmetic nanoemulsions containing Opuntia ficus-indica (L.) mill extract as moisturizing agent.

Science.gov (United States)

Ribeiro, Renato Cesar de Azevedo; Barreto, Stella Maria de Andrade Gomes; Ostrosky, Elissa Aarantes; da Rocha-Filho, Pedro Alves; Veríssimo, Lourena Mafra; Ferrari, Márcio

2015-02-02

This study aimed to produce and characterize an oil in water (O/W) nanoemulsion containing Opuntia ficus-indica (L.) Mill hydroglycolic extract, as well as evaluate its preliminary and accelerated thermal stability and moisturizing efficacy. The formulations containing 0.5% of xanthan gum (FX) and 0.5% of xanthan gum and 1% of Opuntia ficus-indica MILL extract (FXE) were white, homogeneus and fluid in aspect. Both formulations were stable during preliminary and accelerated stability tests. FX and FXE presented a pH compatible to skin pH (4.5-6.0); droplet size varying from 92.2 to 233.6 nm; a polydispersion index (PDI) around 0.200 and a zeta potential from -26.71 to -47.01 mV. FXE was able to increase the water content of the stratum corneum for 5 h after application on the forearm. The O/W nanoemulsions containing 1% of Opuntia ficus-indica (L.) Mill extract presented suitable stability for at least for 60 days. Besides, this formulation was able to increase the water content of stratum corneum, showing its moisturizing efficacy.

Liquid Crystal Gel Reduces Age Spots by Promoting Skin Turnover

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Mina Musashi

2014-07-01

Full Text Available Studies have shown that liquid crystals structurally resembling the intercellular lipids in the stratum corneum can beneficially affect the skin when applied topically by stimulating the skin’s natural regenerative functions and accelerating epidermal turnover. In the present study, the effects of applying low concentrations of a liquid crystal gel of our own creation were evaluated using epidermal thickening in mouse skin as an assay for effective stimulation of epidermal turnover. A liquid crystal gel was also applied topically to human facial skin, and analysis was conducted using before-and-after photographs of age spots, measurements of L* values that reflect degree of skin pigmentation, single-layer samples of the stratum corneum obtained via tape-stripping, and measurements of trans-epidermal water loss that reflect the status of the skin’s barrier function. The results suggested that cost-effective creams containing as low as 5% liquid crystal gel might be effective and safely sold as skin care products targeting age spots and other problems relating to uneven skin pigmentation.

Numerical Simulation of a Non-volcanic Hydrothermal System Caused by Formation of a High Permeability Fracture Zone

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Oka, Daisuke; Ehara, Sachio; Fujimitsu, Yasuhiro

2010-05-01

Because in the Japanese islands the earth crust activity is very active, a disposal stratum for high-level radioactive waste produced by reprocessing the spent nuclear fuel from nuclear power plants will be selected in the tectonically stable areas in which the waste can be disposed underground safely for a long term and there is no influence of earthquakes, seismic activities, volcanic activities, upheaval, sedimentation, erosion, climate and global sea level change and so on, which causes the risk of the inflow of the groundwater to destroy the disposal site or the outflow to the ground surface. However, even if the disposal stratum in such condition will be chosen, in case that a new high permeability fracture zone is formed by the earthquake, and a new hydrothermal system may be formed for a long term (thousands or millions years) and the system may affect the disposal site. Therefore, we have to understand the feature of the non-volcanic hydrothermal system through the high permeability fracture zone. We estimated such influence by using HYDROTHERM Ver2.2 (Hayba & Ingebritsen, 1994), which is a three-dimensional numerical reservoir simulator. The model field is the northwestern part of Kego Fault, which was formed by a series of earthquakes called "the 2005 Fukuoka Prefecture Western Offshore Earthquakes" (the main shock of Mjma 7.0 on 20 March 2005) in Kyushu, Japan. The results of the numerical simulations show the development of a low temperature hydrothermal system as a new fracture zone is formed, in case that there is no volcanic heat source. The results of the simulations up to 100,000 years after formation of the fracture zone show that the higher heat flow and the wider and more permeable fracture zone accelerate the development of the hydrothermal system in the fracture zone. As a result of calculation of up to10 million years, we clarified the evolutional process of the non-volcanic hydrothermal system through the high permeability fracture zone. At

Urea uptake enhances barrier function and antimicrobial defense in humans by regulating epidermal gene expression

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Grether-Beck, Susanne; Felsner, Ingo; Brenden, Heidi; Kohne, Zippora; Majora, Marc; Marini, Alessandra; Jaenicke, Thomas; Rodriguez-Martin, Marina; Trullas, Carles; Hupe, Melanie; Elias, Peter M.; Krutmann, Jean

2012-01-01

Urea is an endogenous metabolite, known to enhance stratum corneum hydration. Yet, topical urea anecdotally also improves permeability barrier function, and it appears to exhibit antimicrobial activity. Hence, we hypothesized that urea is not merely a passive metabolite, but a small-molecule regulator of epidermal structure and function. In 21 human volunteers, topical urea improved barrier function in parallel with enhanced antimicrobial peptide (LL-37 and β-defensin-2) expression. Urea both stimulates expression of, and is transported into keratinocytes by two urea transporters, UT-A1 and UT-A2, and by aquaporin 3, 7 and 9. Inhibitors of these urea transporters block the downstream biological effects of urea, which include increased mRNA and protein levels for: (i) transglutaminase-1, involucrin, loricrin and filaggrin; (ii) epidermal lipid synthetic enzymes, and (iii) cathelicidin/LL-37 and β-defensin-2. Finally, we explored the potential clinical utility of urea, showing that topical urea applications normalized both barrier function and antimicrobial peptide expression in a murine model of atopic dermatitis (AD). Together, these results show that urea is a small-molecule regulator of epidermal permeability barrier function and antimicrobial peptide expression after transporter uptake, followed by gene regulatory activity in normal epidermis, with potential therapeutic applications in diseased skin. PMID:22418868

Imaging mass spectrometry visualizes ceramides and the pathogenesis of dorfman-chanarin syndrome due to ceramide metabolic abnormality in the skin.

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Naoko Goto-Inoue

Full Text Available Imaging mass spectrometry (IMS is a useful cutting edge technology used to investigate the distribution of biomolecules such as drugs and metabolites, as well as to identify molecular species in tissues and cells without labeling. To protect against excess water loss that is essential for survival in a terrestrial environment, mammalian skin possesses a competent permeability barrier in the stratum corneum (SC, the outermost layer of the epidermis. The key lipids constituting this barrier in the SC are the ceramides (Cers comprising of a heterogeneous molecular species. Alterations in Cer composition have been reported in several skin diseases that display abnormalities in the epidermal permeability barrier function. Not only the amounts of different Cers, but also their localizations are critical for the barrier function. We have employed our new imaging system, capable of high-lateral-resolution IMS with an atmospheric-pressure ionization source, to directly visualize the distribution of Cers. Moreover, we show an ichthyotic disease pathogenesis due to abnormal Cer metabolism in Dorfman-Chanarin syndrome, a neutral lipid storage disorder with ichthyosis in human skin, demonstrating that IMS is a novel diagnostic approach for assessing lipid abnormalities in clinical setting, as well as for investigating physiological roles of lipids in cells/tissues.

Controlling the hydration of the skin though the application of occluding barrier creams.

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Sparr, Emma; Millecamps, Danielle; Isoir, Muriel; Burnier, Véronique; Larsson, Åsa; Cabane, Bernard

2013-03-06

The skin is a barrier membrane that separates environments with profoundly different water contents. The barrier properties are assured by the outer layer of the skin, the stratum corneum (SC), which controls the transepidermal water loss. The SC acts as a responding membrane, since its hydration and permeability vary with the boundary condition, which is the activity of water at the outer surface of the skin. We show how this boundary condition can be changed by the application of a barrier cream that makes a film with a high resistance to the transport of water. We present a quantitative model that predicts hydration and water transport in SC that is covered by such a film. We also develop an experimental method for measuring the specific resistance to water transport of films made of occluding barrier creams. Finally, we combine the theoretical model with the measured properties of the barrier creams to predict how a film of cream changes the activity of water at the outer surface of the SC. Using the known variations of SC permeability and hydration with the water activity in its environment (i.e. the relative humidity), we can thus predict how a film of barrier cream changes SC hydration.

Heat: A Highly Efficient Skin Enhancer for Transdermal Drug Delivery

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Sabine Szunerits

2018-02-01

Full Text Available Advances in materials science and bionanotechnology have allowed the refinements of current drug delivery systems, expected to facilitate the development of personalized medicine. While dermatological topical pharmaceutical formulations such as foams, creams, lotions, gels, etc., have been proposed for decades, these systems target mainly skin-based diseases. To treat systemic medical conditions as well as localized problems such as joint or muscle concerns, transdermal delivery systems (TDDSs, which use the skin as the main route of drug delivery, are very appealing. Over the years, these systems have shown to offer important advantages over oral as well as intravenous drug delivery routes. Besides being non-invasive and painless, TDDSs are able to deliver drugs with a short-half-life time more easily and are well adapted to eliminate frequent administrations to maintain constant drug delivery. The possibility of self-administration of a predetermined drug dose at defined time intervals makes it also the most convenient personalized point-of-care approach. The transdermal market still remains limited to a narrow range of drugs. While small and lipophilic drugs have been successfully delivered using TDDSs, this approach fails to deliver therapeutic macromolecules due to size-limited transport across the stratum corneum, the outermost layer of the epidermis. The low permeability of the stratum corneum to water-soluble drugs as well as macromolecules poses important challenges to transdermal administration. To widen the scope of drugs for transdermal delivery, new procedures to enhance skin permeation to hydrophilic drugs and macromolecules are under development. Next to iontophoresis and microneedle-based concepts, thermal-based approaches have shown great promise to enhance transdermal drug delivery of different therapeutics. In this inaugural article for the section “Frontiers in Bioengineering and Biotechnology,” the advances in this field

Heat: A Highly Efficient Skin Enhancer for Transdermal Drug Delivery

Science.gov (United States)

Szunerits, Sabine; Boukherroub, Rabah

2018-01-01

Advances in materials science and bionanotechnology have allowed the refinements of current drug delivery systems, expected to facilitate the development of personalized medicine. While dermatological topical pharmaceutical formulations such as foams, creams, lotions, gels, etc., have been proposed for decades, these systems target mainly skin-based diseases. To treat systemic medical conditions as well as localized problems such as joint or muscle concerns, transdermal delivery systems (TDDSs), which use the skin as the main route of drug delivery, are very appealing. Over the years, these systems have shown to offer important advantages over oral as well as intravenous drug delivery routes. Besides being non-invasive and painless, TDDSs are able to deliver drugs with a short-half-life time more easily and are well adapted to eliminate frequent administrations to maintain constant drug delivery. The possibility of self-administration of a predetermined drug dose at defined time intervals makes it also the most convenient personalized point-of-care approach. The transdermal market still remains limited to a narrow range of drugs. While small and lipophilic drugs have been successfully delivered using TDDSs, this approach fails to deliver therapeutic macromolecules due to size-limited transport across the stratum corneum, the outermost layer of the epidermis. The low permeability of the stratum corneum to water-soluble drugs as well as macromolecules poses important challenges to transdermal administration. To widen the scope of drugs for transdermal delivery, new procedures to enhance skin permeation to hydrophilic drugs and macromolecules are under development. Next to iontophoresis and microneedle-based concepts, thermal-based approaches have shown great promise to enhance transdermal drug delivery of different therapeutics. In this inaugural article for the section “Frontiers in Bioengineering and Biotechnology,” the advances in this field and the handful of

Use of jet grouting to create a low permeability horizontal barrier below an incinerator ash landfill

International Nuclear Information System (INIS)

Furth, A.J.; Burke, G.K.; Deutsch, W.L. Jr.

1997-01-01

The City of Philadelphia's Division of Aviation (DOA) has begun construction of a new commuter runway, designated as Runway 8-26, at the Philadelphia International Airport. A portion of this runway will be constructed over a former Superfund site known as the Enterprise Avenue Landfill, which for many years was used to dispose of solid waste incinerator ash and other hazardous materials. The site was clay capped in the 1980's, but in order for the DOA to use the site, additional remediation was needed to meet US EPA final closure requirements. One component of the closure plan included installation of a low permeability horizontal barrier above a very thin (approximately 0.61 to 0.91 meters) natural clay stratum which underlies an approximately 1020 m 2 area of the landfill footprint so as to insure that a minimum 1.52 meter thick low permeability barrier exists beneath the entire 150,000 m 2 landfill. The new barrier was constructed using jet grouting techniques to achieve remote excavation and replacement of the bottom 0.91 meters of the waste mass with a low permeability grout. The grout was formulated to meet the low permeability, low elastic modulus and compressive strength requirements of the project design. This paper will discuss the advantages of using jet grouting for the work and details the development of the grout mixture, modeling of the grout zone under load, field construction techniques, performance monitoring and verification testing

Diversity and wiring variability of visual local neurons in the Drosophila medulla M6 stratum.

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Chin, An-Lun; Lin, Chih-Yung; Fu, Tsai-Feng; Dickson, Barry J; Chiang, Ann-Shyn

2014-12-01

Local neurons in the vertebrate retina are instrumental in transforming visual inputs to extract contrast, motion, and color information and in shaping bipolar-to-ganglion cell transmission to the brain. In Drosophila, UV vision is represented by R7 inner photoreceptor neurons that project to the medulla M6 stratum, with relatively little known of this downstream substrate. Here, using R7 terminals as references, we generated a 3D volume model of the M6 stratum, which revealed a retinotopic map for UV representations. Using this volume model as a common 3D framework, we compiled and analyzed the spatial distributions of more than 200 single M6-specific local neurons (M6-LNs). Based on the segregation of putative dendrites and axons, these local neurons were classified into two families, directional and nondirectional. Neurotransmitter immunostaining suggested a signal routing model in which some visual information is relayed by directional M6-LNs from the anterior to the posterior M6 and all visual information is inhibited by a diverse population of nondirectional M6-LNs covering the entire M6 stratum. Our findings suggest that the Drosophila medulla M6 stratum contains diverse LNs that form repeating functional modules similar to those found in the vertebrate inner plexiform layer. © 2014 Wiley Periodicals, Inc.

Biodegradation of hard keratins by two bacillus strains.

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Laba, Wojciech; Rodziewicz, Anna

2014-02-01

Extensive quantities of keratinic by-products are disposed annually by animal-processing industry, causing a mounting ecological problem due to extreme resilience of these materials to enzymatic breakdown. There is a growing trend to apply cheap and environment-friendly methods to recycle keratinic wastes. Soil bacteria of profound keratinolytic potential, especially spore-forming rods from the genus Bacillus, play a significant role in keratinase-mediated biodegradation of keratins, therefore could be effective in hastening their biodegradation. Keratin hydrolysis in microbial cultures is one of the most promising techniques not only to utilize this protein but also to obtain valuable by products. The study was undertaken to investigate the biodegradation process of various keratinic materials by two Bacillus strains. Two keratinolytic strains, Bacillus cereus and B. polymyxa, were subject to cultures in the presence of several keratinic appendages, like chicken feathers, barbs and rachea of ostrich feathers, pig bristle, lamb wool, human hair and stratum corneum of epidermis, as main nutrient sources. Bacterial ability to decompose these waste materials was evaluated, at the background of keratinase and protease biosynthesis, in brief four-day cultures. Keratinolytic activity was measured on soluble keratin preparation and proteases were assayed on casein. Additionally, amounts of liberated proteins, amino acids and thiols were evaluated. Residual keratin weight was tested afterwards. Both tested strains proved to be more adapted for fast biodegradation of feather β-keratins than hair-type α-keratins. B. cereus revealed its significant proteolytic potential, especially on whole chicken feathers (230 PU) and stratum corneum (180 PU), but also on separated barbs and rachea, which appeared to be moderate protease inducers. Keratinolytic activity of B. cereus was comparable on most substrates and maximum level obtained was 11 KU. B. polymyxa was found to be a

The effect of sedimentation background of depression target stratum containing mineral in Erlian basin, Ulanqab to uranium mineralization type

International Nuclear Information System (INIS)

Kang Shihu; Jiao Yangquan; Men Hong; Kuang Wenzhan

2012-01-01

The ore bearing stratum in depression of Ulanqab contains target stratum of lower cretaceous Saihan formation, upper cretaceous Erlian formation, paleogene system etc. The uranium mineralization type which have found by now contains sandstone type, mudstone type and coal petrography. The genetic type of mineral deposit contains paleovalley-type, reformed type after superposition with sedimentation and diagenesis by sedimentation. Uranium mineralization of both the natural type and genetic type have close relationship with its ore bearing stratum. Different geological background forms different sedimentary system combination, and different sedimentary system combination forms different uranium mineralization type. (authors)

Relationship between soft stratum thickness and predominant frequency of ground based on microtremor observation data

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Chia, Kenny; Lau, Tze Liang

2017-07-01

Despite categorized as low seismicity group, until being affected by distant earthquake ground motion from Sumatra and the recent 2015 Sabah Earthquake, Malaysia has come to realize that seismic hazard in the country is real and has the potential to threaten the public safety and welfare. The major concern in this paper is to study the effect of local site condition, where it could amplify the magnitude of ground vibration at sites. The aim for this study is to correlate the thickness of soft stratum with the predominant frequency of soil. Single point microtremor measurements were carried out at 24 selected points where the site investigation reports are available. Predominant period and frequency at each site are determined by Nakamura's method. The predominant period varies from 0.22 s to 0.98 s. Generally, the predominant period increases when getting closer to the shoreline which has thicker sediments. As far as the thickness of the soft stratum could influence the amplification of seismic wave, the advancement of micotremor observation to predict the thickness of soft stratum (h) from predominant frequency (fr) is of the concern. Thus an empirical relationship h =54.917 fr-1.314 is developed based on the microtremor observation data. The empirical relationship will be benefited in the prediction of thickness of soft stratum based on microtremor observation for seismic design with minimal cost compared to conventional boring method.

A Case of Peeling Skin Syndrome.

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Singhal, Anil K; Yadav, Devendra K; Soni, Bajrang; Arya, Savita

2017-01-01

Peeling skin syndrome is a very rare autosomal recessive disease characterized by widespread painless peeling of the skin in superficial sheets. Etiology is still unknown with an autosomal recessive inheritance. Less than 100 cases have been reported in the medical literature. We present a 32-year-old man having asymptomatic peeling of skin since birth. Sheets of skin were peeling from his neck, trunk, and extremities, following friction or rubbing especially if pre-soaked in water but sparing palm and soles. Histologically, there was epidermal separation at the level of stratum corneum, just above the stratum granulosum. This case is being presented due to its rarity.

A case of peeling skin syndrome

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Anil K Singhal

2017-01-01

Full Text Available Peeling skin syndrome is a very rare autosomal recessive disease characterized by widespread painless peeling of the skin in superficial sheets. Etiology is still unknown with an autosomal recessive inheritance. Less than 100 cases have been reported in the medical literature. We present a 32-year-old man having asymptomatic peeling of skin since birth. Sheets of skin were peeling from his neck, trunk, and extremities, following friction or rubbing especially if pre-soaked in water but sparing palm and soles. Histologically, there was epidermal separation at the level of stratum corneum, just above the stratum granulosum. This case is being presented due to its rarity.

Acral peeling skin syndrome in two East-African siblings: case report

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Kiprono Samson K

2012-03-01

Full Text Available Abstract Background Acral peeling skin syndrome is a rare autosomal recessive genodermatosis due to a missense mutation in transglutaminase 5. The skin peeling occurs at the separation of the stratum corneum from the stratum granulosum. Case presentation We present a case of two siblings who developed continuous peeling of the palms and soles from the first year of life. This peeling was more severe on the soles than palms and on younger sibling than elder sibling. Peeling is worsened by occlusion and sweating. Conclusions Sporadic cases of Acral Peeling Skin Syndrome occur in African population. There is variability in time of presentation and clinical severity even within families.

Aspects relating to stability of modified passive stratum on TiO2 nanostructure

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Ionita, Daniela; Mazare, Anca; Portan, Diana; Demetrescu, Ioana

2011-04-01

Two kinds of nanotube structures differing from the point of view of their dimensions were obtained using anodizing in two different fluoride electrolytes and these structures were investigated regarding stability. The nanotubes have diameters of around 100 and 65 nm, respectively, and the testing solutions were simulated body fluids (SBF) and NaCl 0.9%. As stability experiments, cyclic voltammetry was performed and ions release was measured. The quantity of released cations in time as a kinetic aspect of passive stratum behavior was followed with an inductively coupled plasma mass spectrometer (ICP-MS) and apatite forming in SBF was found with infrared spectra. This study led to a comparison between the modification and the behavior of passive stratum on nanotubes as a function of their diameters.

Microneedle-based drug delivery systems for transdermal route.

Science.gov (United States)

Pierre, Maria Bernadete Riemma; Rossetti, Fabia Cristina

2014-03-01

Transdermal delivery offers an attractive, noninvasive administration route but it is limited by the skin's barrier to penetration. Minimally invasive techniques, such as the use of microneedles (MNs), bypass the stratum corneum (SC) barrier to permit the drug's direct access to the viable epidermis. These novel micro devices have been developed to puncture the skin for the transdermal delivery of hydrophilic drugs and macromolecules, including peptides, DNA and other molecules, that would otherwise have difficulty passing the outermost layer of the skin, the SC. Using the tools of the microelectronics industry, MNs have been fabricated with a range of sizes, shapes and materials. MNs have been shown to be robust enough to penetrate the skin and dramatically increase the skin permeability of several drugs. Moreover, MNs have reduced needle insertion pain and tissue trauma and provided controlled delivery across the skin. This review focuses on the current state of the art in the transdermal delivery of drugs using various types of MNs and developments in the field of microscale devices, as well as examples of their uses and clinical safety.

Production and Characterization of Cosmetic Nanoemulsions Containing Opuntia ficus-indica (L. Mill Extract as Moisturizing Agent

Directory of Open Access Journals (Sweden)

Renato Cesar de Azevedo Ribeiro

2015-02-01

Full Text Available This study aimed to produce and characterize an oil in water (O/W nanoemulsion containing Opuntia ficus-indica (L. Mill hydroglycolic extract, as well as evaluate its preliminary and accelerated thermal stability and moisturizing efficacy. The formulations containing 0.5% of xanthan gum (FX and 0.5% of xanthan gum and 1% of Opuntia ficus-indica Mill extract (FXE were white, homogeneous and fluid in aspect. Both formulations were stable during preliminary and accelerated stability tests. FX and FXE presented a pH compatible to skin pH (4.5–6.0; droplet size varying from 92.2 to 233.6 nm; a polydispersion index (PDI around 0.200 and a zeta potential from −26.71 to −47.01 mV. FXE was able to increase the water content of the stratum corneum for 5 h after application on the forearm. The O/W nanoemulsions containing 1% of Opuntia ficus-indica (L. Mill extract presented suitable stability for at least for 60 days. Besides, this formulation was able to increase the water content of stratum corneum, showing its moisturizing efficacy.

Polymeric Films Loaded with Vitamin E and Aloe vera for Topical Application in the Treatment of Burn Wounds

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Gabriela Garrastazu Pereira

2014-01-01

Full Text Available Burns are serious traumas related to skin damage, causing extreme pain and possibly death. Natural drugs such as Aloe vera and vitamin E have been demonstrated to be beneficial in formulations for wound healing. The aim of this work is to develop and evaluate polymeric films containing Aloe vera and vitamin E to treat wounds caused by burns. Polymeric films containing different quantities of sodium alginate and polyvinyl alcohol (PVA were characterized for their mechanical properties and drug release. The polymeric films, which were produced, were thin, flexible, resistant, and suitable for application on damaged skin, such as in burn wounds. Around 30% of vitamin E acetate was released from the polymeric films within 12 hours. The in vivo experiments with tape stripping indicated an effective accumulation in the stratum corneum when compared to a commercial cream containing the same quantity of vitamin E acetate. Vitamin E acetate was found in higher quantities in the deep layers of the stratum corneum when the film formulation was applied. The results obtained show that the bioadhesive films containing vitamin E acetate and Aloe vera could be an innovative therapeutic system for the treatment of burns.

Recent Advances in Skin Penetration Enhancers for Transdermal Gene and Drug Delivery.

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Amjadi, Morteza; Mostaghaci, Babak; Sitti, Metin

2017-01-01

There is a growing interest in transdermal delivery systems because of their noninvasive, targeted, and on-demand delivery of gene and drugs. However, efficient penetration of therapeutic compounds into the skin is still challenging largely due to the impermeability of the outermost layer of the skin, known as stratum corneum. Recently, there have been major research activities to enhance the skin penetration depth of pharmacological agents. This article reviews recent advances in the development of various strategies for skin penetration enhancement. We show that approaches such as ultrasound waves, laser, and microneedle patches have successfully been employed to physically disrupt the stratum corneum structure for enhanced transdermal delivery. Rather than physical approaches, several non-physical route have also been utilized for efficient transdermal delivery across the skin barrier. Finally, we discuss some clinical applications of transdermal delivery systems for gene and drug delivery. This paper shows that transdermal delivery devices can potentially function for diverse healthcare and medical applications while further investigations are still necessary for more efficient skin penetration of gene and drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Novel drug delivery strategies for porphyrins and porphyrin precursors

Science.gov (United States)

Morrow, D. I. J.; Donnelly, R. F.

2009-06-01

superficial lesions, such as actinic keratosis. In addition, photodynamic antimicrobial chemotherapy (PACT) is attracting increasing interest for the treatment of infection. However, delivery strategies for topical PDT and PACT are still based on application of rather simplistic cream and solution formulations, with little consideration given to thermodynamics, targeting or the physicochemical properties of the active agent. Purpose-designed dosage forms for topical delivery of aminolevulinic acid or its esters include creams containing penetration enhancers and/or iron chelators, pressure sensitive patches and bioadhesive patches. Such systems aim to enhance drug delivery across the stratum corneum and keratinised debris overlying neoplastic lesions and improve subsequent protoporphyrin IX (PpIX) production. The alternative to using porphyrin precursors is the use of pre-formed photosensitisers. However, owing to their relatively high molecular weights, conventional topical application is not appropriate. Innovative strategies, such as the use of needle-free injections and microneedle arrays, bypass the stratum corneum, enabling rapid and targeted delivery not only porphyrin precursors but also pre-formed photosensitisers. This presentation will review drug delivery work published to date in the fields of PDT and PACT. In addition, the benefits of employing the latest advances in pharmaceutical technology will be highlighted.

Rapid fabrication method of a microneedle mold with controllable needle height and width.

Science.gov (United States)

Lin, Yen-Heng; Lee, I-Chi; Hsu, Wei-Chieh; Hsu, Ching-Hong; Chang, Kai-Ping; Gao, Shao-Syuan

2016-10-01

The main issue of transdermal drug delivery is that macromolecular drugs cannot diffuse through the stratum corneum of skin. Many studies have pursued micro-sized needles encapsulated with drugs to overcome this problem, as these needles can pierce the stratum corneum and allow drugs to enter the circulatory system of the human body. However, most microneedle fabrication processes are time-consuming and require expensive equipment. In this study, we demonstrate a rapid method for fabricating a microneedle mold using drawing lithography and a UV-cured resin. The mold was filled with a water-soluble material, polyvinylpyrrolidone (PVP), which was then demolded to produce a water-soluble microneedle array. The results of an in vitro skin insertion test using PVP microneedles and pig ear skin demonstrated the feasibility of the microneedle mold. In addition, by controlling the viscosity of the UV-cured resin through various heat treatments, microneedles with different heights and aspect ratios were produced. Compared with other methods, this technology significantly simplifies and accelerates the mold fabrication process. In addition, the required equipment is relatively simple and inexpensive. Through this technology, we can rapidly fabricate microneedle molds with controllable dimensions for various applications.

Polymeric films loaded with vitamin E and aloe vera for topical application in the treatment of burn wounds.

Science.gov (United States)

Pereira, Gabriela Garrastazu; Guterres, Sílvia Stanisçuaki; Balducci, Anna Giulia; Colombo, Paolo; Sonvico, Fabio

2014-01-01

Burns are serious traumas related to skin damage, causing extreme pain and possibly death. Natural drugs such as Aloe vera and vitamin E have been demonstrated to be beneficial in formulations for wound healing. The aim of this work is to develop and evaluate polymeric films containing Aloe vera and vitamin E to treat wounds caused by burns. Polymeric films containing different quantities of sodium alginate and polyvinyl alcohol (PVA) were characterized for their mechanical properties and drug release. The polymeric films, which were produced, were thin, flexible, resistant, and suitable for application on damaged skin, such as in burn wounds. Around 30% of vitamin E acetate was released from the polymeric films within 12 hours. The in vivo experiments with tape stripping indicated an effective accumulation in the stratum corneum when compared to a commercial cream containing the same quantity of vitamin E acetate. Vitamin E acetate was found in higher quantities in the deep layers of the stratum corneum when the film formulation was applied. The results obtained show that the bioadhesive films containing vitamin E acetate and Aloe vera could be an innovative therapeutic system for the treatment of burns.

Barreira cutânea na dermatite atópica Skin barrier in atopic dermatitis

Directory of Open Access Journals (Sweden)

Flavia Alvim Sant'Anna Addor

2010-04-01

Full Text Available O estudo da barreira cutânea e de suas propriedades ganhou impulso a partir da década de 60, com estudos que apontaram sua resistência de forma isolada e suas propriedades com relação à permeação cutânea. Paralelamente, a descrição dos corpos de Odland auxiliou a compreensão da manutenção da estabilidade da camada córnea. O modelo brick & mortar, em que os corneócitos são os tijolos e o cimento são os lipídeos intercelulares, é o mais aceito, até o momento. Atualmente, há evidências consistentes de que o estrato córneo é uma estrutura metabolicamente ativa e exerce funções adaptativas. A barreira cutânea também tem um papel na resposta inflamatória, com ativação de melanócitos, angiogênese e fibroplasia, cuja intensidade depende, basicamente, da intensidade da agressão. As anormalidades da barreira cutânea da dermatite atópica são clinicamente observáveis pela presença de pele seca, achado muito frequente e significativo, que constitui parâmetro iagnóstico e de acompanhamento. O grau de hidratação da camada córnea, assim como a perda de água transepidérmica (transepidermal water loss - TEWL, estão relacionados com o grau de dano à barreira, constituindo parâmetros biofísicos que permitem acompanhar os pacientes de maneira não invasiva e com maior grau de sensibilidade.Research about the skin barrier and its properties has increased significantly since the 60s, with studies that indicated its resistance when isolated, as well as its particularities in relation to skin permeability. At the same time, description of Odland bodies helped to understand how stratum corneum stability is maintained. The “brick and mortarâ€� model is the most accepted so far. In this analogy, the corneocytes are the bricks and the intercellular lipids are the mortar. Currently, there is concrete evidence that the stratum corneum is an active metabolic structure that holds adaptive functions, interacting

Comparison of atmospheric microplasma and plasma jet irradiation for increasing of skin permeability

International Nuclear Information System (INIS)

Shimizu, K; Tran, N A; Hayashida, K; Blajan, M

2016-01-01

Atmospheric plasma is attracting interest for medical applications such as sterilization, treatment of cancer cells and blood coagulation. Application of atmospheric plasma in dermatology has potential as a novel tool for wound healing, skin rejuvenation and treatment of wrinkles. In this study, we investigated the enhancement of percutaneous absorption of dye as alternative agents of transdermal drugs. Hypodermic needles are often the only way to deliver large-molecule drugs into the dermis, although a safe transdermal drug delivery method that does not require needles would be desirable. We therefore explored the feasibility of using atmospheric microplasma irradiation to enhance percutaneous absorption of drugs, as an alternative delivery method to conventional hypodermic needles. Pig skin was used as a biological sample, exposed to atmospheric microplasma, and analyzed by attenuated total reflection-Fourier transform infrared spectroscopy. A tape stripping test, a representative method for evaluating skin barrier performance, was also conducted for comparison. Transepidermal water loss (TEWL) was measured and compared with and without atmospheric microplasma irradiation, to quantify water evaporation from the inner body through the skin barrier. The results show that the stratum corneum, the outermost skin layer, could be chemically and physically modified by atmospheric microplasma irradiation. Physical damage to the skin by microplasma irradiation and an atmospheric plasma jet was also assessed by observing the skin surface. The results suggest that atmospheric microplasma has the potential to enhance percutaneous absorption. (paper)

Evaluation of Diclofenac Prodrugs for Enhancing Transdermal Delivery

OpenAIRE

Lobo, Shabbir; Li, Henan; Farhan, Nashid; Yan, Guang

2013-01-01

The purpose of this study was to evaluate the approach of using diclofenac acid (DA) prodrugs for enhancing transdermal delivery. Methanol diclofenac ester (MD), ethylene glycol diclofenac ester (ED), glycerol diclofenac ester (GD), and 1,3-propylene glycol diclofenac ester (PD) were synthesized and evaluated for their physicochemical properties such as solubilities, octanol/water partition coefficients, stratum corneum/water partition coefficients, hydrolysis rates, and bioconversion rates. ...

Fate of chemicals in skin after dermal application: does the in vitro skin reservoir affect the estimate of systemic absorption?

International Nuclear Information System (INIS)

Yourick, Jeffrey J.; Koenig, Michael L.; Yourick, Debra L.; Bronaugh, Robert L.

2004-01-01

Recent international guidelines for the conduct of in vitro skin absorption studies put forward different approaches for addressing the status of chemicals remaining in the stratum corneum and epidermis/dermis at the end of a study. The present study investigated the fate of three chemicals [dihydroxyacetone (DHA), 7-(2H-naphtho[1,2-d]triazol-2-yl)-3-phenylcoumarin (7NTPC), and disperse blue 1 (DB1)] in an in vitro absorption study. In these studies, human and fuzzy rat skin penetration and absorption were determined over 24 or 72 h in flow-through diffusion cells. Skin penetration of these chemicals resulted in relatively low receptor fluid levels but high skin levels. For DHA, penetration studies found approximately 22% of the applied dose remaining in the skin (in both the stratum corneum and viable tissue) as a reservoir after 24 h. Little of the DHA that penetrates into skin is actually available to become systemically absorbed. 7NTPC remaining in the skin after 24 h was approximately 14.7% of the applied dose absorbed. Confocal laser cytometry studies with 7NTPC showed that it is present across skin in mainly the epidermis and dermis with intense fluorescence around hair. For DB1, penetration studies found approximately 10% (ethanol vehicle) and 3% (formulation vehicle) of the applied dose localized in mainly the stratum corneum after 24 h. An extended absorption study (72 h) revealed that little additional DB1 was absorbed into the receptor fluid. Skin levels should not be considered as absorbed material for DHA or DB1, while 7NTPC requires further investigation. These studies illustrate the importance of determining the fate of chemicals remaining in skin, which could significantly affect the estimates of systemically available material to be used in exposure estimates. We recommend that a more conclusive means to determine the fate of skin levels is to perform an extended study as conducted for DB1

Stratum corneum integrity as a predictor for peristomal skin problems in ostomates

DEFF Research Database (Denmark)

Nybaek, H; Lophaven, Søren Nymand; Karlsmark, T

2010-01-01

BACKGROUND: Peristomal skin problems are common, most often the result is disruption of the skin barrier and this may account for more than one in three visits to ostomy nurses. Therefore a specific assessment of individual risk factors relating to the skin barrier function would be of great...... interest. METHODS: Skin barrier integrity in ostomy patients with peristomal skin problems (PSP) was compared with that of ostomy patients with normal skin (controls) using transepidermal water loss (TEWL). Mechanical barrier disruption was determined by a tape stripping test and chemical barrier...

Emotional intelligence is a second-stratum factor of intelligence: evidence from hierarchical and bifactor models.

Science.gov (United States)

MacCann, Carolyn; Joseph, Dana L; Newman, Daniel A; Roberts, Richard D

2014-04-01

This article examines the status of emotional intelligence (EI) within the structure of human cognitive abilities. To evaluate whether EI is a 2nd-stratum factor of intelligence, data were fit to a series of structural models involving 3 indicators each for fluid intelligence, crystallized intelligence, quantitative reasoning, visual processing, and broad retrieval ability, as well as 2 indicators each for emotion perception, emotion understanding, and emotion management. Unidimensional, multidimensional, hierarchical, and bifactor solutions were estimated in a sample of 688 college and community college students. Results suggest adequate fit for 2 models: (a) an oblique 8-factor model (with 5 traditional cognitive ability factors and 3 EI factors) and (b) a hierarchical solution (with cognitive g at the highest level and EI representing a 2nd-stratum factor that loads onto g at λ = .80). The acceptable relative fit of the hierarchical model confirms the notion that EI is a group factor of cognitive ability, marking the expression of intelligence in the emotion domain. The discussion proposes a possible expansion of Cattell-Horn-Carroll theory to include EI as a 2nd-stratum factor of similar standing to factors such as fluid intelligence and visual processing.

Epiphytic flora on Gelidium corneum (Rhodophyta: Gelidiales in relation to wave exposure and depth

Directory of Open Access Journals (Sweden)

Endika Quintano

2015-12-01

Full Text Available The canopy-forming macroalga Gelidium corneum (Hudson J.V. Lamouroux plays a major role in the functioning of the subtidal ecosystem of the Cantabrian Sea (northern Spain. Despite its importance, little is known about the factors that may potentially affect the distribution pattern of its epiphytic flora. Here we examine two indirect factors: coastal orientation (N and NW and depth (3 and 7 m, as proxies for wave exposure and light availability, respectively. We test their effects on the total epiphytic load, alpha diversity (species richness, Shannon, Simpson and evenness measures and multivariate structure of the epiphytic flora growing on G. corneum in subtidal waters off the Basque coast. Plocamium cartilagineum, Dictyota dichotoma and Acrosorium ciliolatum were found to be the most common epiphytes. Significant interactive effect of coastal orientation and depth were observed for species composition and abundance of epiphytic flora. Increased wave exposure resulted in a lower epiphyte load and a less diverse community, suggesting that under high hydrodynamic conditions epiphytes were more likely to become dislodged from hosts. However, light availability only had a significant effect on the distribution of epiphytes below a certain threshold of wave action, with the epiphytic load being 30-40% greater on shallow bottoms.

Sub-stratum injection of fine tailings

Energy Technology Data Exchange (ETDEWEB)

Kesteren van, W.; Cornelisse, J.; Costello, M. [Deltares, Delft (Netherlands)

2010-07-01

This PowerPoint presentation discussed an experiment conducted to evaluate the sub-stratum injection of oil sands fine tailings. The hydraulic fracturing method was developed as a sub-surface dredging process for mining sand without removing the overburden. Pressure was used to transport the sand-water mixture, and the high pressures used in the process resulted in water losses through the clay-sand interface. The experiment was conducted with soft clay, compacted sand, and an injection feed. Results of the study showed that the injection method may be successful. However, further research is required to characterize the fracture energy of oil sands and the rheology of fine tailings. Horizontal hydraulic fracturing equations were presented. Tensile failures in clay and oil sands were discussed. Fractures were identified by deformation and discharge rates. Crack propagation methods were also studied. tabs., figs.

Application of Gelidium corneum edible films containing carvacrol for ham packages.

Science.gov (United States)

Lim, G O; Hong, Y H; Song, K B

2010-01-01

We prepared an edible film of Gelidium corneum (GC) containing carvacrol as an antimicrobial and antioxidative agent. The GC film containing carvacrol significantly decreased the WVP, while TS and %E values were increased, compared to the film without carvacrol. Increasing amounts of an antimicrobial agent increased antimicrobial activity against Escherichia coli O157:H7 and Listeria monocytogenes. Application of the film to ham packaging successfully inhibited the microbial growth and lipid oxidation of ham during storage. Our results indicate that GC film can be a useful edible packaging material for food products, and the incorporation of carvacrol in the GC film may extend the shelf life.

Which Stratum of Urban Elderly Is Most Vulnerable for Dementia?

Science.gov (United States)

2016-01-01

Many factors associated with a patient's lifestyle may disrupt timely access to dementia diagnosis and management. The aim of this study was to compare characteristics of lifestyle factors at the time of initial evaluation for dementia across degrees of dementia, and to identify risk factors relating to late detection of dementia, in order to understand the various lifestyle barriers to timely recognition of the disease. We reviewed medical records of 1,409 subjects who were diagnosed as dementia among 35,723 inhabitants of Gwangjin-gu. Dementia severity was divided into three degrees. Age, sex, education, income, smoking, heavy drinking, physical activity, religion, and living conditions were evaluated. There was a significantly greater proportion of individuals who were old age, female, less educated, who had never smoked or drank heavily, without physical activity, with no religious activity and living with family other than spouse in the severe dementia group. The lifestyle risks of late detection were old age, lower education, less social interactions, less physical activity or living with family. We can define this group of patients as the vulnerable stratum to dementia evaluation. Health policy or community health services might find ways to better engage patients in this vulnerable stratum to dementia. PMID:27550494

An In Vitro Skin Equivalent for Evaluation of Skin Absorption of Compounds

Science.gov (United States)

2008-12-01

acid (100 µg/ml) and a Peroxisome Proliferator Activated Receptor (PPAR) agonist clofibrate (300 µM) was added to the media during culture at the ALI...factors (lipids, ascorbic acid and clofibrate ), a full thickness HSE was obtained with a differentiated epidermis. Addition of external lipids or... acid (100µg/ml) and clofibrate (300 µm), the HSE exhibited relatively higher number of viable epidermal layers and a thicker stratum corneum as

White piedra, black piedra, tinea versicolor, and tinea nigra: contribution to the diagnosis of superficial mycosis.

Science.gov (United States)

Veasey, John Verrinder; Avila, Ricardo Bertozzi de; Miguel, Barbara Arruda Fraletti; Muramatu, Laura Hitomi

2017-01-01

Superficial mycoses are fungal infections restricted to the stratum corneum and to the hair shafts, with no penetration in the epidermis; they are: white piedra, black piedra, tinea versicolor, and tinea nigra. This study presents images of mycological tests performed in the laboratory, as well as exams performed at the authors office, in order to improve the dermatologist's knowledge about the diagnosis of these dermatoses, which are common in many countries.

Palmoplantar Lichen Planus: Dört olgu sunumu

OpenAIRE

Uçmak, Derya; Azizoğlu, Ruken; Harman, Mehmet

2011-01-01

Lichen planus is a benign, inflammatory and itchy dermatosis that is incurred by skin, skin extensions and mucosa. Lichen planus rarely show palmoplantar involvement. Since stratum corneum in palmoplantar lichen planus is extremely thick, lesions can be yellow colored instead of the purple colored papules that are classic lesions. Clinically, it might be confused with psoriasis, secondary syphilis, verruca vulgaris, hyperkeratotic eczema, palmoplantar keratodermas, hyperkeratotic type tinea p...

Closed-Loop Noninvasive Ultrasound Glucose Sensing and Insulin Delivery

Science.gov (United States)

2007-09-01

mechanism suggests that ultrasound interacts with the structured lipids within the intracellular channels of the stratum corneum to permeabilize the...R. Prausnitz, “Mechanism of intracellular delivery by acoustic cavitation ,” Ultrasound Med. Biol. 32, 915–924 2006. 14E. Maione, K. K. Shung, R. J...result of cavitation (11– 14). Low frequency ultrasound is capable of generating microbubbles in the water and tissue. These bubbles allow water

Physical properties of Gelidium corneum-gelatin blend films containing grapefruit seed extract or green tea extract and its application in the packaging of pork loins.

Science.gov (United States)

Hong, Y-H; Lim, G-O; Song, K B

2009-01-01

Edible Gelidium corneum-gelatin (GCG) blend films containing grapefruit seed extract (GFSE) or green tea extract (GTE) were manufactured, and the quality of pork loins packed with the film during storage was determined. Tensile strength (TS) and water vapor permeability (WVP) of the films containing GFSE or GTE were better than those of the control. The film's antimicrobial activity against Escherichia coli O157:H7 and Listeria monocytogenes increased with increasing antimicrobial concentration, resulting in a decrease in the populations of bacteria by 0.77 to 2.08 and 0.91 to 3.30 log CFU/g, respectively. Pork loin samples were inoculated with E. coli O157:H7 and L. monocytogenes. The samples packed with the GCG film containing GFSE (0.08%) or GTE (2.80%) had a decrease in the populations of E. coli O157:H7 and L. monocytogenes of 0.69 to 1.11 and 1.05 to 1.14 log CFU/g, respectively, compared to the control after 4 d of storage. The results showed that the quality of pork loins during storage could be improved by packaging them with the GCG film containing GFSE or GTE.

Developments in permeable and low permeability barriers

International Nuclear Information System (INIS)

Jefferis, S.A.; Norris, G.H.; Thomas, A.O.

1997-01-01

The concept of the reactive treatment zone whereby pollutants are attenuated as they move along a pathway in the ground has enabled a re-thinking of many of the concepts of containment. In particular it offers the potential for the control of the flux from a contaminated area by controlling the contaminant concentration in the pathway(s) as well as or instead of using a low permeability barrier. The paper outlines the basic concepts of the reactive treatment zone and the use of permeable and low permeability reactive systems. The paper then gives a case history of the installation of a permeable barrier using an in-situ reaction chamber

Impact of the gap between socioeconomic stratum and subjective social class on depressive symptoms: unique insights from a longitudinal analysis.

Science.gov (United States)

Kim, Jae-Hyun; Lee, Sang Gyu; Shin, Jaeyong; Park, Eun-Cheol

2014-11-01

Our objective was to investigate whether gaps between socioeconomic stratum and subjective social class affect the prevalence of depressive symptoms. We collected data from the Korean Health Panel Survey, years 2009 and 2011, and performed a longitudinal analysis of 12,357 individuals at baseline (2009), estimating the prevalence of depressive symptoms among individuals with disparate socioeconomic stratum (High, Middle, or Low household income and education level, respectively) and subjective social class (High, Middle, or Low). The odds ratio for depressive symptoms among individuals with High household income and High social class, or Low household income and Low social class, was 0.537 and 1.877, respectively (psocioeconomic stratum and subjective social class on depressive symptoms deteriorated, as a whole, across the socioeconomic spectrum. The gap between socioeconomic stratum and perceived position in the social hierarchy explains a substantial part of inequalities in the prevalence of depressive symptoms. It is important to consider the impact of discrepancies between different measures of socioeconomic well-being on depressive symptoms rather than looking at the subjective social class alone. Copyright © 2014 The Authors. Published by Elsevier Ltd. All rights reserved.

Bayes allocation of the sample for estimation of the mean when each stratum has a Poisson distribution

International Nuclear Information System (INIS)

Wright, T.

1983-01-01

Consider a stratified population with L strata, so that a Poisson random variable is associated with each stratum. The parameter associated with the hth stratum is theta/sub h/, h = 1, 2, ..., L. Let ω/sub h/ be the known proportion of the population in the hth stratum, h = 1, 2, ..., L. The authors want to estimate the parameter theta = summation from h = 1 to L ω/sub h/theta/sub h/. We assume that prior information is available on theta/sub h/ and that it can be expressed in terms of a gamma distribution with parameters α/sub h/ and β/sub h/, h = 1, 2, ..., L. We also assume that the prior distributions are independent. Using squared error loss function, a Bayes allocation of total sample size with a cost constraint is given. The Bayes estimate using the Bayes allocation is shown to have an adjusted mean square error which is strictly less than the adjusted mean square error of the classical estimate using the classical allocation

Effect of forage inclusion and particle size in diets of neonatal lambs on performance and rumen development.

Science.gov (United States)

Norouzian, M A; Valizadeh, R

2014-12-01

A slaughter experiment was conducted to determine the effects of alfalfa particle size on rumen morphology and performance of lambs. Twenty-four Balouchi lambs aged 21 days (9.1 ± 1.1 kg) were randomly fed control (diet without alfalfa hay; CON) and mixed rations containing 15% finely ground (FINE; 2 mm) and 15% coarsely chopped alfalfa hay (LONG; 3 to 4 cm). After a 63 days feeding period, nine animals (three per treatment) were slaughtered to obtain ruminal tissue samples for morphological analyses. Alfalfa particle size did not affect (p > 0.05) papillae density, height, width, epithelium depth and surface area. Coarse alfalfa decreased the stratum corneum and increased (p content and nor RNA concentration of rumen tissue was affected by feeding different diets. Forage particle size did not affect the blood concentration of glucose, urea nitrogen (BUN), beta-hydroxybutyric acid (BHBA) and non-esterified fatty acids (NEFA). Dry matter intake and feed conversion ratio were higher for control diet; however, there were no significant differences between treatments for average daily gain. These data suggest that coarse alfalfa significantly reduces the stratum corneum and increases muscularity of rumen wall and tended to better feed conversion ratio. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Study on the Use of Microbial Cellulose as a Biocarrier for 1,3-Dihydroxy-2-Propanone and Its Potential Application in Industry

Directory of Open Access Journals (Sweden)

Lidia Stasiak-Różańska

2018-04-01

Full Text Available Can microbial cellulose (MC be used as a bio-carrier for 1,3-dihydroxy-2-propanone (DHA? The aim of this study was to examine the possibility of using MC as a biomaterial for DHA transferring into the stratum corneum and inducing changes in skin color. The MC patches were obtained from Gluconacetobacter xylinus strain and incubated in solutions with various concentrations of DHA (g·L−1: 20; 50; 80; 110 at 22 °C for 24 h. Afterwards; the patches were applied onto the skin for 15, 30, or 60 min. Skin color changes were assessed visually compared to a control patches without DHA. The intensity of skin color was increasing with the increase of DHA concentration and time of patches application. Application of MC patches with DHA (50 g·L−1 for 30 min ensured the color which was considered the closest to the desired natural tan effect. MC patches containing DHA can be biocarriers enabling DHA transport into the stratum corneum and causing skin color changes. Study results indicate a new possibility for industrial applications of MC; e.g., as a biocarrier in masking the symptoms of vitiligo or production of self-tanning agents in the form of masks.

Spectroscopic and thermal characterization of alternative model biomembranes from shed skins of Bothrops jararaca and Spilotis pullatus

Directory of Open Access Journals (Sweden)

André Rolim Baby

2009-09-01

Full Text Available Recently, there has been an interest in the use of shed snake skin as alternative model biomembrane for human stratum corneum. This research work presented as objective the qualitative characterization of alternative model biomembranes from Bothrops jararaca and Spilotis pullatus by FT-Raman, PAS-FTIR and DSC. The employed biophysical techniques permitted the characterization of the biomembranes from shed snake skin of B. jararaca and S. pullatus by the identification of vibrational frequencies and endothermic transitions that are similar to those of the human stratum corneum.Existe atualmente interesse no uso da muda de pele de cobra como modelos alternativos de biomembranas da pele humana. O presente trabalho apresentou como objetivo a caracterização qualitativa de modelos alternativos de biomembranas provenientes de mudas de pele de cobra da Bothrops jararaca e Spilotis pullatus por espectroscopia Raman (FT-Raman, espectroscopia fotoacústica no infravermelho (PAS-FTIR e calorimetria exploratória diferencial (DSC. As técnicas biofísicas FT-Raman, PAS-FTIR e DSC permitiram caracterizar qualitativamente os modelos alternativos de biomembranas provenientes das mudas de pele de cobra da B. jararaca e S. pullatus e identificar freqüências vibracionais e transições endotérmicas similares ao estrato córneo humano.

Evaluation of Histopathological Changes in Control Biopsies Which Taken 48 Sessions after NBUVB Phototherapy for Early-Stage Mycosis Fungoides

Directory of Open Access Journals (Sweden)

Ebru Zemheri

2012-01-01

Full Text Available Background. There are not many studies investigating histomorphological changes in 48 sessions in patients with early-stage MF after narrowband UVB (NBUVB treatment. Our purpose is to evaluate histological features of phototherapy after 48 sessions and determine which parameters are more reliable for controlling skin biopsies. Methods. Biopsies of 32 patients with early stage of MF, who were treated with NBUVB phototherapy, were histologically evaluated before and after the treatments, including epidermotropism, stratum corneum, epidermal thickness, dermal infiltration, papillary dermal fibrosis, vascular alterations, and other dermal changes. We discuss the histomorphological effects of NBUVB phototherapy on skin biopsies by comparing the responders with nonresponders, with before and after the treatment. Results. 9 patients (28% did not give any response to treatment. Alleviation in epidermotropism, increases in parakeratosis and normal keratosis, perivascular infiltration, and melanophages, decrease in the lichenoid/patchy lichenoid infiltration pattern after the treatment was statistically significant. Comparing by response, normalization of stratum corneum and epidermis, orthohyperkeratosis, decrease in linearly arranged cells, the lichenoid/patchy lichenoid infiltration, the loss of inflammation were statistically significant in responders group. Conclusion. We detected a significant decrease in linearly arranged cells after phototherapy, indicating that it is an “important diagnostic parameter" in evaluation of therapeutic response.

The use of biodegradable microneedle patches to increase penetration of topical steroid for prurigo nodularis.

Science.gov (United States)

Shin, Jung U; Kim, Jung Dong; Kim, Hong Kee; Kang, Hong Kyu; Joo, Chulmin; Lee, Ju Hee; Jeong, Do Hyeon; Song, Seungri; Chu, Howard; Lee, Jung Soo; Lee, Hemin; Lee, Kwang Hoon

2018-02-01

The stratum corneum is an almost impermeable barrier. Recently, microneedles have been used to increase drug delivery passing the stratum corneum by incorporating the drug within the microneedle or by coating the surface of the microneedle with the drug. This study was performed to investigate whether applying a biodegradable microneedle patch after topical steroid application increases penetration of the steroid in vitro, as well as treatment efficacy in patients with prurigo nodularis. In vitro penetration of topical steroids after biodegradable microneedle patch application was measured using a 3D skin model. To evaluate the treatment efficacy of the combination of biodegradable microneedle and topical steroids, a split-body clinical study was performed. Penetration of topical steroid in the in vitro skin model was significantly greater in the microneedle-applied skin. In a split-body clinical study with prurigo nodularis patients, the area and height of skin lesions decreased after four weeks of treatment on both sides, however, the microneedle patch side exhibited a significantly greater decrease in both area and height, compared to the control side. The pruritus visual analogue scale was also significantly lower on the microneedle side. We suggest that simply applying a microneedle patch after topical steroid application could be a useful strategy for treating refractory skin diseases such as prurigo nodularis.

Gene Silencing in Skin After Deposition of Self-Delivery siRNA With a Motorized Microneedle Array Device

Directory of Open Access Journals (Sweden)

Robyn P Hickerson

2013-01-01

Full Text Available Despite the development of potent siRNAs that effectively target genes responsible for skin disorders, translation to the clinic has been hampered by inefficient delivery through the stratum corneum barrier and into the live cells of the epidermis. Although hypodermic needles can be used to transport siRNA through the stratum corneum, this approach is limited by pain caused by the injection and the small volume of tissue that can be accessed by each injection. The use of microneedle arrays is a less painful method for siRNA delivery, but restricted payload capacity limits this approach to highly potent molecules. To address these challenges, a commercially available motorized microneedle array skin delivery device was evaluated. This device combines the positive elements of both hypodermic needles and microneedle array technologies with little or no pain to the patient. Application of fluorescently tagged self-delivery (sd-siRNA to both human and murine skin resulted in distribution throughout the treated skin. In addition, efficient silencing (78% average reduction of reporter gene expression was achieved in a transgenic fluorescent reporter mouse skin model. These results indicate that this device effectively delivers functional sd-siRNA with an efficiency that predicts successful clinical translation.

Why pens have rubbery grips

Science.gov (United States)

Dzidek, Brygida; Bochereau, Séréna; Johnson, Simon A.; Hayward, Vincent; Adams, Michael J.

2017-10-01

The process by which human fingers gives rise to stable contacts with smooth, hard objects is surprisingly slow. Using high-resolution imaging, we found that, when pressed against glass, the actual contact made by finger pad ridges evolved over time following a first-order kinetics relationship. This evolution was the result of a two-stage coalescence process of microscopic junctions made between the keratin of the stratum corneum of the skin and the glass surface. This process was driven by the secretion of moisture from the sweat glands, since increased hydration in stratum corneum causes it to become softer. Saturation was typically reached within 20 s of loading the contact, regardless of the initial moisture state of the finger and of the normal force applied. Hence, the gross contact area, frequently used as a benchmark quantity in grip and perceptual studies, is a poor reflection of the actual contact mechanics that take place between human fingers and smooth, impermeable surfaces. In contrast, the formation of a steady-state contact area is almost instantaneous if the counter surface is soft relative to keratin in a dry state. It is for this reason that elastomers are commonly used to coat grip surfaces.

High resolution in-vivo imaging of skin with full field optical coherence tomography

Science.gov (United States)

Dalimier, E.; Bruhat, Alexis; Grieve, K.; Harms, F.; Martins, F.; Boccara, C.

2014-03-01

Full-field OCT (FFOCT) has the ability to provide en-face images with a very good axial sectioning as well as a very high transverse resolution (about 1 microns in all directions). Therefore it offers the possibility to visualize biological tissues with very high resolution both on the axial native view, and on vertical reconstructed sections. Here we investigated the potential dermatological applications of in-vivo skin imaging with FFOCT. A commercial FFOCT device was adapted for the in-vivo acquisition of stacks of images on the arm, hand and finger. Several subjects of different benign and pathological skin conditions were tested. The images allowed measurement of the stratum corneum and epidermis thicknesses, measurement of the stratum corneum refractive index, size measurement and count of the keratinocytes, visualization of the dermal-epidermal junction, and visualization of the melanin granules and of the melanocytes. Skins with different pigmentations could be discriminated and skin pathologies such as eczema could be identified. The very high resolution offered by FFOCT both on axial native images and vertical reconstructed sections allows for the visualization and measurement of a set of parameters useful for cosmetology and dermatology. In particular, FFOCT is a potential tool for the understanding and monitoring of skin hydration and pigmentation, as well as skin inflammation.

Topical Apigenin Alleviates Cutaneous Inflammation in Murine Models

Directory of Open Access Journals (Sweden)

Mao-Qiang Man

2012-01-01

Full Text Available Herbal medicines have been used in preventing and treating skin disorders for centuries. It has been demonstrated that systemic administration of chrysanthemum extract exhibits anti-inflammatory properties. However, whether topical applications of apigenin, a constituent of chrysanthemum extract, influence cutaneous inflammation is still unclear. In the present study, we first tested whether topical applications of apigenin alleviate cutaneous inflammation in murine models of acute dermatitis. The murine models of acute allergic contact dermatitis and acute irritant contact dermatitis were established by topical application of oxazolone and phorbol 12-myristate 13-acetate (TPA, respectively. Inflammation was assessed in both dermatitis models by measuring ear thickness. Additionally, the effect of apigenin on stratum corneum function in a murine subacute allergic contact dermatitis model was assessed with an MPA5 physiology monitor. Our results demonstrate that topical applications of apigenin exhibit therapeutic effects in both acute irritant contact dermatitis and allergic contact dermatitis models. Moreover, in comparison with the vehicle treatment, topical apigenin treatment significantly reduced transepidermal water loss, lowered skin surface pH, and increased stratum corneum hydration in a subacute murine allergic contact dermatitis model. Together, these results suggest that topical application of apigenin could provide an alternative regimen for the treatment of dermatitis.

Skin surface hydration decreases rapidly during long distance flights.

Science.gov (United States)

Guéhenneux, Sabine; Gardinier, Sophie; Morizot, Frederique; Le Fur, Isabelle; Tschachler, Erwin

2012-05-01

Dehydration of the stratum corneum leads to sensations and symptoms of 'dry skin' such as skin tightness and itchiness. As these complaints are frequently experienced by airline travellers, the aim of this study was to investigate the changes in skin surface hydration during long distance flights. The study was performed on four healthy Caucasian, and on four Japanese women aged 29-39 years, travelling on long distance flights. They had stopped using skin care products at least 12 h before, and did not apply them during the flights. The air temperature and relative humidity inside the cabin, as well as skin capacitance of the face and forearm of participants, were registered at several time points before and during the flights. Relative humidity of the aircraft cabin dropped to levels below 10% within 2 h after take-off and stayed at this value throughout the flight. Skin capacitance decreased rapidly on both the face and forearms with most pronounced changes on the cheeks where it decreased by up to 37%. Our results demonstrate that during long distance flights, the aircraft cabin environment leads to a rapid decrease in stratum corneum hydration, an alteration, which probably accounts for the discomfort experienced by long distance aircraft travellers. © 2011 John Wiley & Sons A/S.

Emu oil-based lotion effects on neonatal skin barrier during transition from intrauterine to extrauterine life

Directory of Open Access Journals (Sweden)

Zanardo V

2017-08-01

Full Text Available Vincenzo Zanardo,1 David Giarrizzo,2 Francesca Volpe,1 Lara Giliberti,1 Gianluca Straface1 1Division of Perinatal Medicine, Policlinico Abano Terme, Abano Terme, 2CALANTHA Physiology of Lactation Laboratory, Padua, Italy Abstract: Both appropriate hydration and skin surface pH are fundamental in preventing baby skin barrier damage during transition from intrauterine to extrauterine life. However, effects of topical moisturizers on neonatal stratum corneum temperature, pH, hydration, and elasticity have not been scientifically evaluated in vivo. We checked 31 full-term breastfeeding neonates by non-invasive bioengineering method, which is able to evaluate the basal skin barrier (left heel, and assessed at 6±1 hours after birth, and at 1 and 24 hours after emu oil-based topical treatment. The basal skin barrier of right heel (no oil exposure of each newborn was considered as control. We found that a single application of an emu oil-based lotion was effective in improving heel stratum corneum hydration, which increases both skin pH and elasticity without any effect on temperature. Further studies are needed to confirm long-term beneficial effects of this treatment in a very sensitive patient population. Keywords: skin barrier, neonate, emu oil-based lotion, topical treatment

Crustal permeability

Science.gov (United States)

Gleeson, Tom; Ingebritsen, Steven E.

2016-01-01

Permeability is the primary control on fluid flow in the Earth’s crust and is key to a surprisingly wide range of geological processes, because it controls the advection of heat and solutes and the generation of anomalous pore pressures.  The practical importance of permeability – and the potential for large, dynamic changes in permeability – is highlighted by ongoing issues associated with hydraulic fracturing for hydrocarbon production (“fracking”), enhanced geothermal systems, and geologic carbon sequestration.  Although there are thousands of research papers on crustal permeability, this is the first book-length treatment.  This book bridges the historical dichotomy between the hydrogeologic perspective of permeability as a static material property and the perspective of other Earth scientists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. 

Successful treatment of proximal white subungual onychomycosis with oral terbinafine therapy

International Nuclear Information System (INIS)

Aman, S.; Nadeem, M.; Haroon, T.S.

2008-01-01

Proximal white subungual onychomycosis (PWSO) is a rare form of onychomycosis of both fingernails and toenails. It occurs when the fungus invades the stratum corneum of the proximal nailfold followed by infection of the deeper parts of the nail plate. The surface of the overlying nail is usually normal. A case of PWSO is described with complete cure by the use of oral terbinafine 250 mg/day for 3 months continuously. (author)

Liquid Crystal Gel Reduces Age Spots by Promoting Skin Turnover

OpenAIRE

Mina Musashi; Ariella Coler-Reilly; Teruaki Nagasawa; Yoshiki Kubota; Satomi Kato; Yoko Yamaguchi

2014-01-01

Studies have shown that liquid crystals structurally resembling the intercellular lipids in the stratum corneum can beneficially affect the skin when applied topically by stimulating the skin’s natural regenerative functions and accelerating epidermal turnover. In the present study, the effects of applying low concentrations of a liquid crystal gel of our own creation were evaluated using epidermal thickening in mouse skin as an assay for effective stimulation of epidermal turnover. A liquid ...

White piedra, black piedra, tinea versicolor, and tinea nigra: contribution to the diagnosis of superficial mycosis*

Science.gov (United States)

Veasey, John Verrinder; de Avila, Ricardo Bertozzi; Miguel, Barbara Arruda Fraletti; Muramatu, Laura Hitomi

2017-01-01

Superficial mycoses are fungal infections restricted to the stratum corneum and to the hair shafts, with no penetration in the epidermis; they are: white piedra, black piedra, tinea versicolor, and tinea nigra. This study presents images of mycological tests performed in the laboratory, as well as exams performed at the authors office, in order to improve the dermatologist's knowledge about the diagnosis of these dermatoses, which are common in many countries. PMID:29186263

Efficacy and Tolerability of a Facial Serum for Fine Lines, Wrinkles, and Photodamaged Skin

OpenAIRE

Mccall-Perez, Fred; Stephens, Thomas J.; Herndon, James H.

2011-01-01

Background: Dermatology visits for the prevention and treatment of aging skin are rapidly increasing. The clinical sequelae including wrinkling, pigmentary changes, roughness, laxity, and telangiectasia can all result in the appearance of aging skin, impacting quality of life. A facial serum was developed with ingredients associated with an improvement in the appearance of fine lines and wrinkles and increase in stratum corneum barrier function. Patients were instructed to use a gentle wash b...

Female Rats are Less Susceptible during Puberty to Lethal Effects of Percutaneous Exposure to VX

Science.gov (United States)

2015-12-17

lethal dose determination for percutaneous exposure to soman and VX in guinea pigs and the effectiveness of decontamination with M291 SDK or SANDIA...di-isopropylamino) ethyl] methyl phosphonthioate) through pig , human and guinea pig skin in vitro, Toxicol. In Vitro 20 (2006) 1532–1536. [6] R... production and transepidermal water loss [TEWL]) change with age [3,14,15]. As reviewed in Ref. [28], the barrier function of the stratum corneum is

Side-by-side comparison of an open-chamber (TM 300) and a closed-chamber (Vapometer™) transepidermal water loss meter.

Science.gov (United States)

Steiner, Markus; Aikman-Green, Sylvie; Prescott, Gordon J; Dick, Finlay D

2011-08-01

The measurement of transepidermal water loss (TEWL) is used to monitor changes in the stratum corneum's permeability to water vapor. This measurement is widely used in the cosmetics industry and in dermatology research. However, only limited work has been undertaken to assess the comparability of results from different TEWL meters over an extended range of measurements. This study compared the results of TEWL measurements between two commonly used open-chamber and closed-chamber TEWL devices. Five hundred and forty measurements were taken in 17 participants on the dorsum and palm of both hands on two different days and the order of the devices was randomized. The results showed that the open TEWL meter's capacity for measuring high values of TEWL was restricted, and that the closed-chamber TEWL meter was less sensitive to differences in the lower range of measurements. Both devices have their strengths for different applications, but their results cannot be directly compared. We were unable to find a statistical model that would allow us to transform the measurements made on one device for a comparison with the results generated by the other device. © 2011 John Wiley & Sons A/S.

Spray-on transdermal drug delivery systems.

Science.gov (United States)

Ibrahim, Sarah A

2015-02-01

Transdermal drug delivery possesses superior advantages over other routes of administration, particularly minimizing first-pass metabolism. Transdermal drug delivery is challenged by the barrier nature of skin. Numerous technologies have been developed to overcome the relatively low skin permeability, including spray-on transdermal systems. A transdermal spray-on system (TSS) usually consists of a solution containing the drug, a volatile solvent and in many cases a chemical penetration enhancer. TSS promotes drug delivery via the complex interplay between solvent evaporation and drug-solvent drag into skin. The volatile solvent carries the drug into the upper layers of the stratum corneum, and as the volatile solvent evaporates, an increase in the thermodynamic activity of the drug occurs resulting in an increased drug loading in skin. TSS is easily applied, delivering flexible drug dosage and associated with lower incidence of skin irritation. TSS provides a fast-drying product where the volatile solvent enables uniform drug distribution with minimal vehicle deposition on skin. TSS ensures precise dose administration that is aesthetically appealing and eliminates concerns of residual drug associated with transdermal patches. Furthermore, it provides a better alternative to traditional transdermal products due to ease of product development and manufacturing.

Prolonged sojourn of developing pyramidal cells in the intermediate zone of the hippocampus and their settling in the stratum pyramidale

International Nuclear Information System (INIS)

Altman, J.; Bayer, S.A.

1990-01-01

In radiograms of rat embryos that received a single dose of [3H]thymidine between days E16 and E20 and were killed 24 hours after the injection, the heavily labeled cells (those that ceased to multiply soon after the injection) form a horizontal layer in the intermediate zone of the hippocampus, called the inferior band. The fate of these heavily labeled cells was traced in radiograms of the dorsal hippocampus in embryos that received [3H]thymidine on day E18 and were killed at different intervals thereafter. Two hours after injection the labeled proliferative cells are located in the Ammonic neuroepithelium. The heavily labeled cells that leave the neuroepithelium and aggregate in the inferior band 1 day after the injection become progressively displaced toward the stratum pyramidale 2-3 days later, and penetrate the stratum pyramidale of the CA1 region on the 4th day. In the stratum pyramidale of the CA3 region, farther removed from the Ammonic neuroepithelium, the heavily labeled cells are still sojourning in the intermediate zone 4 days after labeling. Observations in methacrylate sections suggest that two morphogenetic features of the developing hippocampus may contribute to the long sojourn of young pyramidal cells in the intermediate zone: the way in which the stratum pyramidale forms and the way in which the alveolar channels develop. The stratum pyramidale of the CA1 region forms before that of the CA3 region, which is the reverse of the neurogenetic gradient in the production of pyramidal cells. We hypothesize that this is so because the pyramidal cells destined to settle in the CA3 region, which will be contacted by granule cells axons (the mossy fibers), have to await the formation of the granular layer on days E21-E22

Effect of permeability enhancers on paracellular permeability of acyclovir.

Science.gov (United States)

Ates, Muge; Kaynak, Mustafa Sinan; Sahin, Selma

2016-06-01

According to Biopharmaceutics Classification System (BCS), acyclovir is a class III (high solubility, low permeability) compound, and it is transported through paracellular route by passive diffusion. The aim of this study was to investigate the effect of various pharmaceutical excipients on the intestinal permeability of acyclovir. The single-pass in-situ intestinal perfusion (SPIP) method was used to estimate the permeability values of acyclovir and metoprolol across different intestinal segments (jejunum, ileum and colon). Permeability coefficient (Peff ) of acyclovir was determined in the absence and presence of a permeation enhancer such as dimethyl β-cyclodextrin (DM-β-CD), sodium lauryl sulfate (SLS), sodium caprate (Cap-Na) and chitosan chloride. All enhancers increased the permeability of paracellularly transported acyclovir. Although Cap-Na has the highest permeability-enhancing effect in all segments, permeation-enhancing effect of chitosan and SLS was only significant in ileum. On the other hand, DM-β-CD slightly decreased the permeability in all intestinal segments. These findings have potential implication concerning the enhancement of absorption of paracellularly transported compounds with limited oral bioavailability. In the case of acyclovir, Cap-Na either alone or in combination with SLS or chitosan has the potential to improve its absorption and bioavailability and has yet to be explored. © 2016 Royal Pharmaceutical Society.

Investigations of percutaneous uptake of ultrafine TiO2 particles at the high energy ion nanoprobe LIPSION

International Nuclear Information System (INIS)

Menzel, F.; Reinert, T.; Vogt, J.; Butz, T.

2004-01-01

Micronised TiO 2 particles with a diameter of about 15 nm are used in sunscreens as physical UV filter. Due to the small particle size it may be supposed that TiO 2 particles can pass through the uppermost horny skin layer (stratum corneum) via intercellular channels and penetrate into deeper vital skin layers. Accumulations of TiO 2 particles in the skin can decrease the threshold for allergies of the immune system or cause allergic reactions directly. Spatially resolved ion beam analysis (PIXE, RBS, STIM and secondary electron imaging) was carried out on freeze-dried cross-sections of biopsies of pig skin, on which four different formulations containing TiO 2 particles were applied. The investigations were carried out at the high energy ion nanoprobe LIPSION in Leipzig with a 2.25 MeV proton beam, which was focused to a diameter of 1 μm. The analysis concentrated on the penetration depth and on pathways of the TiO 2 particles into the skin. In these measurements a penetration of TiO 2 particles through the s. corneum into the underlying stratum granulosum via intercellular space was found. Hair follicles do not seem to be important penetration pathways because no TiO 2 was detected inside. The TiO 2 particle concentration in the stratum spinosum was below the minimum detection limit of about 1 particle/μm 2 . These findings show the importance of coating the TiO 2 particles in order to prevent damage of RNA and DNA of skin cells by photocatalytic reactions of the penetrated particles caused by absorption of UV light

Investigations of percutaneous uptake of ultrafine TiO{sub 2} particles at the high energy ion nanoprobe LIPSION

Energy Technology Data Exchange (ETDEWEB)

Menzel, F. E-mail: fmenzel@physik.uni-leipzig.de; Reinert, T.; Vogt, J.; Butz, T

2004-06-01

Micronised TiO{sub 2} particles with a diameter of about 15 nm are used in sunscreens as physical UV filter. Due to the small particle size it may be supposed that TiO{sub 2} particles can pass through the uppermost horny skin layer (stratum corneum) via intercellular channels and penetrate into deeper vital skin layers. Accumulations of TiO{sub 2} particles in the skin can decrease the threshold for allergies of the immune system or cause allergic reactions directly. Spatially resolved ion beam analysis (PIXE, RBS, STIM and secondary electron imaging) was carried out on freeze-dried cross-sections of biopsies of pig skin, on which four different formulations containing TiO{sub 2} particles were applied. The investigations were carried out at the high energy ion nanoprobe LIPSION in Leipzig with a 2.25 MeV proton beam, which was focused to a diameter of 1 {mu}m. The analysis concentrated on the penetration depth and on pathways of the TiO{sub 2} particles into the skin. In these measurements a penetration of TiO{sub 2} particles through the s. corneum into the underlying stratum granulosum via intercellular space was found. Hair follicles do not seem to be important penetration pathways because no TiO{sub 2} was detected inside. The TiO{sub 2} particle concentration in the stratum spinosum was below the minimum detection limit of about 1 particle/{mu}m{sup 2}. These findings show the importance of coating the TiO{sub 2} particles in order to prevent damage of RNA and DNA of skin cells by photocatalytic reactions of the penetrated particles caused by absorption of UV light.

Bovine rumen epithelium undergoes rapid structural adaptations during grain-induced subacute ruminal acidosis.

Science.gov (United States)

Steele, Michael A; Croom, Jim; Kahler, Melissa; AlZahal, Ousama; Hook, Sarah E; Plaizier, Kees; McBride, Brian W

2011-06-01

Alterations in rumen epithelial structure and function during grain-induced subacute ruminal acidosis (SARA) are largely undescribed. In this study, four mature nonlactating dairy cattle were transitioned from a high-forage diet (HF; 0% grain) to a high-grain diet (HG; 65% grain). After feeding the HG diet for 3 wk, the cattle were transitioned back to the original HF diet, which was fed for an additional 3 wk. Continuous ruminal pH was measured on a weekly basis, and rumen papillae were biopsied during the baseline and at the first and final week of each diet. The mean, minimum, and maximum daily ruminal pH were depressed (P < 0.01) in the HG period compared with the HF period. During the HG period, SARA was diagnosed only during week 1, indicating ruminal adaptation to the HG diet. Microscopic examination of the papillae revealed a reduction (P < 0.01) in the stratum basale, spinosum, and granulosum layers, as well as total depth of the epithelium during the HG period. The highest (P < 0.05) papillae lesion scores were noted during week 1 when SARA occurred. Biopsied papillae exhibited a decline in cellular junctions, extensive sloughing of the stratum corneum, and the appearance of undifferentiated cells near the stratum corneum. Differential mRNA expression of candidate genes, including desmoglein 1 and IGF binding proteins 3, 5, and 6, was detected between diets using qRT-PCR. These results suggest that the structural integrity of the rumen epithelium is compromised during grain feeding and is associated with the differential expression of genes involved in epithelial growth and structure.

Skin toxicity of jet fuels: ultrastructural studies and the effects of substance P

International Nuclear Information System (INIS)

Monteiro-Riviere, Nancy A.; Inman, Alfred O.; Riviere, Jim E.

2004-01-01

Topical exposure to jet fuel is a significant occupational hazard. Recent studies have focused on dermal absorption of fuel and its components, or alternatively, on the biochemical or immunotoxicological sequelae to exposure. Surprisingly, morphological and ultrastructural analyses have not been systematically conducted. Similarly, few studies have compared responses in skin to that of the primary target organ, the lung. The focus of the present investigation was 2-fold: first, to characterize the ultrastructural changes seen after topical exposure to moderate doses (335 or 67 μl/cm 2 ) of jet fuels [Jet A, Jet Propellant (JP)-8, JP-8+100] for up to 4 days in pigs, and secondly, to determine if co-administration of substance P (SP) with JP-8 jet fuel in human epidermal keratinocyte cell cultures modulates toxicity as it does to pulmonary toxicity in laboratory animal studies. The primary change seen after exposure to all fuels was low-level inflammation accompanied by formation of lipid droplets in various skin layers, mitochondrial and nucleolar changes, cleft formation in the intercellular lipid lamellar bilayers, as well as disorganization in the stratum granulosum-stratum corneum interface. An increased number of Langerhans cells were also noted in jet fuel-treated skin. These changes suggest that the primary effect of jet fuel exposure is damage to the stratum corneum barrier. SP administration decreased the release of interleukin (IL)-8 normally seen in keratinocytes after JP-8 exposure, a response similar to that reported for SP's effect on JP-8 pulmonary toxicity. These studies provide a base upon which biochemical and immunological data collected in other model systems can be compared

Stratum corneum damage and ex vivo porcine skin water absorption - a pilot study

DEFF Research Database (Denmark)

Duch Lynggaard, C; Bang Knudsen, D; Jemec, G B E

2009-01-01

A simple ex vivo screening technique would be of interest for mass screening of substances for potential barrier disruptive qualities. Ex vivo water absorption as a marker of skin barrier integrity was studied on pig ear skin. Skin water absorption was quantified by weighing and weight changes were...... found to reflect prehydration barrier damage. It is suggested that this simple model may be elaborated to provide a rapid, economical screening tool for potential skin irritants....

Investigation of the interaction between modified ISCOMs and stratum corneum lipid model systems

DEFF Research Database (Denmark)

Madsen, Henriette Baun; Arboe-Andersen, Helle M.; Rozlosnik, Noemi

2010-01-01

The modified ISCOMs, so-called Posintro (TM) nanoparticles, provide an opportunity for altering the surface charge of the particles, which influences their affinity for the negatively charged antigen sites, cell membranes and lipids in the skin. Hypothetically, this increases the passage of the I...

Skin Membrane Electrical Impedance Properties under the Influence of a Varying Water Gradient

Science.gov (United States)

Björklund, Sebastian; Ruzgas, Tautgirdas; Nowacka, Agnieszka; Dahi, Ihab; Topgaard, Daniel; Sparr, Emma; Engblom, Johan

2013-01-01

The stratum corneum (SC) is an effective permeability barrier. One strategy to increase drug delivery across skin is to increase the hydration. A detailed description of how hydration affects skin permeability requires characterization of both macroscopic and molecular properties and how they respond to hydration. We explore this issue by performing impedance experiments on excised skin membranes in the frequency range 1 Hz to 0.2 MHz under the influence of a varying gradient in water activity (aw). Hydration/dehydration induces reversible changes of membrane resistance and effective capacitance. On average, the membrane resistance is 14 times lower and the effective capacitance is 1.5 times higher when the outermost SC membrane is exposed to hydrating conditions (aw = 0.992), as compared to the case of more dehydrating conditions (aw = 0.826). Molecular insight into the hydration effects on the SC components is provided by natural-abundance 13C polarization transfer solid-state NMR and x-ray diffraction under similar hydration conditions. Hydration has a significant effect on the dynamics of the keratin filament terminals and increases the interchain spacing of the filaments. The SC lipids are organized into lamellar structures with ∼ 12.6 nm spacing and hexagonal hydrocarbon chain packing with mainly all-trans configuration of the acyl chains, irrespective of hydration state. Subtle changes in the dynamics of the lipids due to mobilization and incorporation of cholesterol and long-chain lipid species into the fluid lipid fraction is suggested to occur upon hydration, which can explain the changes of the impedance response. The results presented here provide information that is useful in explaining the effect of hydration on skin permeability. PMID:23790372

Ambient humidity and the skin: the impact of air humidity in healthy and diseased states.

Science.gov (United States)

Goad, N; Gawkrodger, D J

2016-08-01

Humidity, along with other climatic factors such as temperature and ultraviolet radiation, can have an important impact on the skin. Limited data suggest that external humidity influences the water content of the stratum corneum. An online literature search was conducted through Pub-Med using combinations of the following keywords: skin, skin disease, humidity, dermatoses, dermatitis, eczema, and mist. Publications included in this review were limited to (i) studies in humans or animals, (ii) publications showing relevance to the field of dermatology, (iii) studies published in English and (iv) publications discussing humidity as an independent influence on skin function. Studies examining environmental factors as composite influences on skin health are only included where the impact of humidity on the skin is also explored in isolation of other environmental factors. A formal systematic review was not feasible for this topic due to the heterogeneity of the available research. Epidemiological studies indicated an increase in eczema with low internal (indoors) humidity and an increase in eczema with external high humidity. Other studies suggest that symptoms of dry skin appear with low humidity internal air-conditioned environments. Murine studies determined that low humidity caused a number of changes in the skin, including the impairment of the desquamation process. Studies in humans demonstrated a reduction in transepidermal water loss (TEWL) (a measure of the integrity of the skin's barrier function) with low humidity, alterations in the water content in the stratum corneum, decreased skin elasticity and increased roughness. Intervention with a humidifying mist increased the water content of the stratum corneum. Conversely, there is some evidence that low humidity conditions can actually improve the barrier function of the skin. Ambient relative humidity has an impact on a range of parameters involved in skin health but the literature is inconclusive. Further

Classification of archaeological pieces into their respective stratum by a chemometric model based on the soil concentration of 25 selected elements

International Nuclear Information System (INIS)

Carrero, J.A.; Goienaga, N.; Fdez-Ortiz de Vallejuelo, S.; Arana, G.; Madariaga, J.M.

2010-01-01

The aim of this work was to demonstrate that an archaeological ceramic piece has remained buried underground in the same stratum for centuries without being removed. For this purpose, a chemometric model based on Principal Component Analysis, Soft Independent Modelling of Class Analogy and Linear Discriminant Analysis classification techniques was created with the concentration of some selected elements of both soil of the stratum and soil adhered to the ceramic piece. Some ceramic pieces from four different stratigraphic units, coming from a roman archaeological site in Alava (North of Spain), and its respective stratum soils were collected. The soil adhered to the ceramic pieces was removed and treated in the same way as the soil from its respective stratum. The digestion was carried out following the US Environmental Pollution Agency EPA 3051A method. A total of 54 elements were determined in the extracts by a rapid screening inductively coupled plasma mass spectrometry method. After rejecting the major elements and those which could have changed from the original composition of the soils (migration or retention from/to the buried objects), the following elements (25) were finally taken into account to construct the model: Li, V, Co, As, Y, Nb, Sn, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Au, Th and U. A total of 33 subsamples were treated from 10 soils belonging to 4 different stratigraphic units. The final model groups and discriminate them in four groups, according to the stratigraphic unit, having both the stratum and soils adhered to the pieces falling down in the same group.

Infrared spectroscopic measurement of skin hydration and sebum levels and comparison to corneometer and sebumeter

OpenAIRE

Ezerskaia, A.; Pereira, S.F.; Urbach, Paul; Varghese, Babu; Popp, Jürgen; Tuchin, Valery V.; Matthews, Dennis L.; Pavone, Francesco S.

2016-01-01

Skin health characterized by a system of water and lipids in Stratum Corneum provide protection from harmful external elements and prevent trans-epidermal water loss. Skin hydration (moisture) and sebum (skin surface lipids) are considered to be important factors in skin health; a right balance between these components is an indication of skin health and plays a central role in protecting and preserving skin integrity. In this manuscript we present an infrared spectroscopic method for simulta...

A Model of Medical Countermeasures for Vesicant Exposure

Science.gov (United States)

2015-10-01

lipophilic, can diffuse readily through the intracellular spaces of the stratum corneum, which are filled with lipids such as sebum, oils , waxes, as...does not decontaminate his skin or his eyes. The resulting injury to the eyes, lungs, and skin are shown in Figure 8-1. Figure 8-1. Eye, Lung, and...R.Vijayaraghavan, & S.C.Pant. (2011). Designing of mouse model: A new approach for studying sulphur mustard-induced skin lesions. Burns . Meier, H. M. (1998

Histological study of white rhinoceros integument

OpenAIRE

Plochocki, Jeffrey H.; Ruiz, Saul; Rodriguez-Sosa, Jos? R.; Hall, Margaret I.

2017-01-01

In this study, we report findings from a microscopic analysis of the white rhinoceros (Ceratotherium simum) integumentary ultrastructure. Skin samples from the cheek, shoulder, flank and rump were taken from a 46-year-old female southern white rhinoceros and examined using H&E and elastic histological stains. The epidermis was thickest in the flank (1.003 mm) followed by the rump, cheek and shoulder. The stratum corneum comprised more than half the epidermal thickness. Numerous melanin granul...

Développement d'un modèle prédictif de la pénétration percutanée par approches chromatographiques et spectroscopiques

OpenAIRE

Jungman , Elsa

2012-01-01

The stratum corneum (SC) is the upper skin layer and due to its particular composition, corneocytes embedded in a lipidic matrix, it owns a role of barrier function and protects our body against water loss, penetration of exogenous molecules and UV irradiation. Its lipidic matrix is composed of three major lipids: fatty acids, cholesterol and ceramides, organised in liquid crystalline phase. This high cohesion creates cement between corneocytes. This cement is the principal pathway taken by t...

Simulations of Skin Barrier Function: Free Energies of Hydrophobic and Hydrophilic Transmembrane Pores in Ceramide Bilayers

OpenAIRE

Notman, Rebecca; Anwar, Jamshed; Briels, W. J.; Noro, Massimo G.; den Otter, Wouter K.

2008-01-01

Transmembrane pore formation is central to many biological processes such as ion transport, cell fusion, and viral infection. Furthermore, pore formation in the ceramide bilayers of the stratum corneum may be an important mechanism by which penetration enhancers such as dimethylsulfoxide (DMSO) weaken the barrier function of the skin. We have used the potential of mean constraint force (PMCF) method to calculate the free energy of pore formation in ceramide bilayers in both the innate gel pha...

Salicylic acid as a peeling agent: a comprehensive review

OpenAIRE

Arif, Tasleem

2015-01-01

Tasleem Arif Postgraduate Department of Dermatology, STD and Leprosy, Government Medical College, Srinagar, Jammu and Kashmir, India Abstract: Salicylic acid has been used to treat various skin disorders for more than 2,000 years. The ability of salicylic acid to exfoliate the stratum corneum makes it a good agent for peeling. In particular, the comedolytic property of salicylic acid makes it a useful peeling agent for patients with acne. Once considered as a keratolytic agent, the role of s...

Suitability of Torrent Permeability Tester to measure air-permeability of covercrete

Energy Technology Data Exchange (ETDEWEB)

Andrade, C.; Gonzales-Gasca, C. [Institute of Construction Sciences ' Eduardo Torroja' , Madrid (Spain); Torrent, R. [Portland Cement Institute, (Argentina)

2000-07-01

Suitability of the Torrent Permeability Tester (TPT) to measure the permeability of covercrete to air, both in the laboratory and the field, is investigated, and test results obtained in laboratory studies are discussed. The tests performed included the determination of air permeability (TPT method), oxygen permeability (Cembureau method) and capillary suction, rapid chloride permeability test (ASTM C 1202), as well as a one-year carbonation depth test. Concrete specimens of various compositions and curing regimes were used in the tests; the gas-permeability tests were repeated on the same specimens after 28 days, than again at 6 months and 12 months. Test results confirmed the suitability of the TPT as a useful tool in the characterization of the quality the of concrete cover. It was found to be sensitive to changes in concrete quality; repeatable for sensitive properties such as gas permeability ; also, it was found to correlate well with other durability-related properties. 10 refs., 8 tabs., 8 figs.

Encapsulation of the UV filters ethylhexyl methoxycinnamate and butyl methoxydibenzoylmethane in lipid microparticles: effect on in vivo human skin permeation.

Science.gov (United States)

Scalia, S; Mezzena, M; Ramaccini, D

2011-01-01

Lipid microparticles loaded with the UVB filter ethylhexyl methoxycinnamate (EHMC) and the UVA filter butyl methoxydibenzoylmethane (BMDBM) were evaluated for their effect on the sunscreen agent's percutaneous penetration. Microparticles loaded with EHMC or BMDBM were prepared by the melt emulsification technique using stearic acid or glyceryl behenate as lipidic material, respectively, and hydrogenate phosphatidylcholine as the surfactant. Nonencapsulated BMDBM and EHMC in conjunction with blank microparticles or equivalent amounts of the 2 UV filters loaded in the lipid microparticles were introduced into oil-in-water emulsions and applied to human volunteers. Skin penetration was investigated in vivo by the tape-stripping technique. For the cream with the nonencapsulated sunscreen agents, the percentages of the applied dose diffused into the stratum corneum were 32.4 ± 4.1% and 30.3 ± 3.3% for EHMC and BMDBM, respectively. A statistically significant reduction in the in vivo skin penetration to 25.3 ± 5.5% for EHMC and 22.7 ± 5.4% for BMDBM was achieved by the cream containing the microencapsulated UV filters. The inhibiting effect on permeation attained by the lipid microparticles was more marked (45-56.3% reduction) in the deeper stratum corneum layers. The reduced percutaneous penetration of BMDBM and EHMC achieved by the lipid microparticles should preserve the UV filter efficacy and limit potential toxicological risks. Copyright © 2011 S. Karger AG, Basel.

Highly deformable and highly fluid vesicles as potential drug delivery systems: theoretical and practical considerations

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Romero EL

2013-08-01

Full Text Available Eder Lilia Romero, Maria Jose Morilla Nanomedicine Research Program, Department of Science and Technology, National University of Quilmes, Bernal, Buenos Aires, Argentina Abstract: Vesicles that are specifically designed to overcome the stratum corneum barrier in intact skin provide an efficient transdermal (systemic or local drug delivery system. They can be classified into two main groups according to the mechanisms underlying their skin interaction. The first group comprises those possessing highly deformable bilayers, achieved by incorporating edge activators to the bilayers or by mixing with certain hydrophilic solutes. The vesicles of this group act as drug carriers that penetrate across hydrophilic pathways of the intact skin. The second group comprises those possessing highly fluid bilayers, owing to the presence of permeation enhancers. The vesicles of this group can act as carriers of drugs that permeate the skin after the barrier of the stratum corneum is altered because of synergistic action with the permeation enhancers contained in the vesicle structure. We have included a detailed overview of the different mechanisms of skin interaction and discussed the most promising preclinical applications of the last five years of Transfersomes® (IDEA AG, Munich, Germany, ethosomes, and invasomes as carriers of antitumoral and anti-inflammatory drugs applied by the topical route. Keywords: Transfersomes, ethosomes, antitumoral, anti-inflammatory, topical delivery

Microemulsion and Microemulsion-Based Gels for Topical Antifungal Therapy with Phytochemicals.

Science.gov (United States)

Boonme, Prapaporn; Kaewbanjong, Jarika; Amnuaikit, Thanaporn; Andreani, Tatiana; Silva, Amélia M; Souto, Eliana B

2016-01-01

Skin fungal infections are regular injuries suffered by people living in tropical areas. Most common pathogens are Trichophyton, Microsporum and Epidermophyton which can cause skin lesions in many parts of body. Topical antifungal phytochemicals are commonly used to avoid systemic adverse events and are more convenient for patient application than those administered by other routes. However, the effectiveness of topical treatments in eradicating fungal infection is more limited since the stratum corneum acts as the skin barrier, resulting in long treatment duration and low patient's compliance. The goal of this work is to identify optimized drug delivery systems to improve topic clinical efficacy. Microemulsions i.e. liquid dispersions of oil and water stabilized with an interfacial film of surfactant are well known drug delivery systems. A thickening agent may be included to form microemulsion-based gels to increase skin adhesion. Microemulsions and microemulsion-based gels can be loaded with several hydrophilic and lipophilic drugs because they are composed of both water and oil phases. Microemulsions and microemulsion-based gels can also be used for the delivery of many drugs including antifungal drugs through stratum corneum due to their capacity to act as skin penetration enhancement. In addition to a comprehensive review of microemulsion and microemulsion-based gels as suitable carriers for skin delivery of various antifungal drugs, this review also aims to discuss the delivery of antifungal phytochemicals.

Localization of dexamethasone within dendritic core-multishell (CMS) nanoparticles and skin penetration properties studied by multi-frequency electron paramagnetic resonance (EPR) spectroscopy.

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Saeidpour, S; Lohan, S B; Anske, M; Unbehauen, M; Fleige, E; Haag, R; Meinke, M C; Bittl, R; Teutloff, C

2017-07-01

The skin and especially the stratum corneum (SC) act as a barrier and protect epidermal cells and thus the whole body against xenobiotica of the external environment. Topical skin treatment requires an efficient drug delivery system (DDS). Polymer-based nanocarriers represent novel transport vehicles for dermal application of drugs. In this study dendritic core-multishell (CMS) nanoparticles were investigated as promising candidates. CMS nanoparticles were loaded with a drug (analogue) and were applied to penetration studies of skin. We determined by dual-frequency electron paramagnetic resonance (EPR) how dexamethasone (Dx) labelled with 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (PCA) is associated with the CMS. The micro-environment of the drug loaded to CMS nanoparticles was investigated by pulsed high-field EPR at cryogenic temperature, making use of the fact that magnetic parameters (g-, A-matrices, and spin-lattice relaxation time) represent specific probes for the micro-environment. Additionally, the rotational correlation time of spin-labelled Dx was probed by continuous wave EPR at ambient temperature, which provides independent information on the drug environment. Furthermore, the penetration depth of Dx into the stratum corneum of porcine skin after different topical applications was investigated. The location of Dx in the CMS nanoparticles is revealed and the function of CMS as penetration enhancers for topical application is shown. Copyright © 2016 Elsevier B.V. All rights reserved.

Skin penetration behaviour of sesquiterpene lactones from different Arnica preparations using a validated GC-MSD method.

Science.gov (United States)

Wagner, Steffen; Merfort, Irmgard

2007-01-04

Preparations of Arnica montana L. are widely used for the topical treatment of inflammatory diseases. The anti-inflammatory activity is mainly attributed to their sesquiterpene lactones (SLs) from the helenalin and 11alpha,13-dihydrohelenalin type. To study the penetration kinetics of SLs in Arnica preparations, a stripping method with adhesive tape and pig skin as a model was used. For the determination of SLs in the stripped layers of the stratum corneum (SC), a gas chromatography/mass spectrometry method was developed and validated. Thereby the amount of helenalin derivatives was calculated as helenalin isobutyrate, and 11alpha,13-dihydrohelenalin derivatives as 11alpha,13-dihydrohelenalin methacrylate. This GC-MSD method is suitable also to determine low amounts of SLs in Arnica preparations. The penetration behaviour of one gel preparation and two ointment preparations was investigated. The SLs of all preparations show a comparable penetration in and a permeation through the stratum corneum, the uppermost part of the skin. Interestingly, the gel preparation showed a decrease of the penetration rate over 4h, whereas the penetration rate of ointments kept constant over time. Moreover, we could demonstrate that the totally penetrated amount of SLs only depends on the kind of the formulation and of the SLs-content in the formulation but not on the SLs composition or on the used extraction agent.

Antioxidant activity of Matricaria chamomilla L. extract and clinical efficacy of cosmetic formulations containing this extract and its isolated compounds

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Ananda T. Nóbrega

2013-12-01

Full Text Available Topical application of antioxidants has proven to be effective in protecting the skin against oxidative damage. Matricaria chamomilla L. extract has been used in cosmetic formulations. The aim of this study was to evaluate the antioxidant potential of chamomile extract as well as the clinical efficacy on skin hydration and mechanical properties of skin. The antioxidant activity of chamomile extract was evaluated by chemiluminescence (IC50 = 0.14 μg/mL. Stable formulations were supplemented with 0,5 cg/g α-bisabolol or cg/gwith 5,0 of Matricaria chamomile glycolic extract or with 0,01 cg/g of apigenin and applied on the volar forearm and face of 25 female subjects. Skin physiology was assessed before and after 2 hours (single application and after a 2- and 4-week period of daily application. After a single application, all formulations increased the stratum corneum water content but only α-bisabolol and chamomile extract formulations reduced TEWL. The formulation with chamomile extract has shown the most pronounced result in the reduction of TEWL (27%. However, after 2- and 4-week application, only the extract formulation increased stratum corneum water content compared with the vehicle. Chamomile extract was effective in neutralizing free radicals and therefore presents an interesting potential in cosmetic formulations for this purpose.

Using low-frequency ultrasound to improve the optical clearing of porcine skin

Science.gov (United States)

Zhong, Huiqing; Guo, Zhouyi; Wei, Huajiang; Zhang, Zude; Zeng, Changchun; Zhai, Juan; He, Yonghong

2008-12-01

The glycerol used as an enhancer for tissue optical clearing technique has been researched. However, using it and a physical way of ultrasound enhance optical clearing of tissue reported a few. We researched that the ultrasound whether can improve the optical clearing of dealt with 80% glycerol tissue. The fresh porcine skins divided into four groups. The first group was not dealt with by ultrasound and 80% glycerol, the second group was dealt with by only ultrasound, the third group was dealt with by 80% glycerol and no by ultrasound, and the fourth group was dealt with by both 80% glycerol and ultrasound. And we measured changes in optical scattering of the porcine skins under treatment with OCT. From the OCT images show that the fourth group changed very faster than the other's during the 0~15 min. And it can be clearly seen that there is a significant improvement in the light penetration depth and imaging contrast in a shorter time. It is possible that the low-frequency ultrasound can make disordering of the stratum corneum lipids of the porcine skin (because the cavitation has happened), and improve the speed of 80% glycerol through the stratum corneum of skin. These results proved that using 80% glycerol with the ultrasound can better improve the optical clearing of tissue.

Development of an Innovative Intradermal siRNA Delivery System Using a Combination of a Functional Stearylated Cytoplasm-Responsive Peptide and a Tight Junction-Opening Peptide

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Hisako Ibaraki

2016-09-01

Full Text Available As a new category of therapeutics for skin diseases including atopic dermatitis (AD, nucleic acids are gaining importance in the clinical setting. Intradermal administration is noninvasive and improves patients′ quality of life. However, intradermal small interfering RNA (siRNA delivery is difficult because of two barriers encountered in the skin: intercellular lipids in the stratum corneum and tight junctions in the stratum granulosum. Tight junctions are the major barrier in AD; therefore, we focused on functional peptides to devise an intradermal siRNA delivery system for topical skin application. In this study, we examined intradermal siRNA permeability in the tape-stripped (20 times back skin of mice or AD-like skin of auricles treated with 6-carboxyfluorescein-aminohexyl phosphoramidite (FAM-labeled siRNA, the tight junction modulator AT1002, and the functional cytoplasm-responsive stearylated peptide STR-CH2R4H2C by using confocal laser microscopy. We found that strong fluorescence was observed deep and wide in the epidermis and dermis of back skin and AD-like ears after siRNA with STR-CH2R4H2C and AT1002 treatment. After 10 h from administration, brightness of FAM-siRNA was significantly higher for STR-CH2R4H2C + AT1002, compared to other groups. In addition, we confirmed the nontoxicity of STR-CH2R4H2C as a siRNA carrier using PAM212 cells. Thus, our results demonstrate the applicability of the combination of STR-CH2R4H2C and AT1002 for effective intradermal siRNA delivery.

Influence of local air velocity from air conditioner evaluated by salivary and skin biomarkers

OpenAIRE

Yamaguchi, Masaki; Takahashi, Takayuki; Yoshino, Yuichiro; Sasaki, Makoto; Nishiyama, Hajime

2010-01-01

The purpose of this paper is to reveal both the psychosomatic and the physical effects of local air velocity from an air conditioner using biomarkers which can be collected noninvasively. Salivary α-amylase activity (SAA) and salivary cortisol were used as the indexes of psychosomatic effects. The total protein (TP) collected from stratum corneum was used as an index of the physical condition of dry skin. A continuous experiment over a 5 days period in summer was conducted using 8 healthy you...

Comparative histopathology of Pityriasis versicolor and Pityrosporum folliculitis

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Mittal R

1992-01-01

Full Text Available Twenty five cases each of pityriasis versicolor (PV and pityrosporum folliculitis (PF were selected for this study. Histopathologically in PV, spores and hyphae in spaghetti and meatball appearance in stratum corneum, and perivascular mononuclear infiltrate were seen. In PF, spores were inside the dilated hair follicles filled with keratin, perifollicular and perivascular mononuclear infiltration were seen. Basket weave hyperkeratosis, edema and disruption of collagen were seen in 88% cases of PF and have not been reported earlier.

Clinical experience with Leptospermum honey use for treatment of hard to heal neonatal wounds: case series.

Science.gov (United States)

Boyar, V; Handa, D; Clemens, K; Shimborske, D

2014-02-01

Preterm, critically ill neonates represent a challenge in wound healing. Many factors predispose infants to skin injuries, including decreased epidermal-dermal cohesion, deficient stratum corneum, relatively alkaline pH of skin surface, impaired nutrition and presence of multiple devices on the skin. We present a case series describing the use of medical-grade honey-Leptospermum honey (Medihoney), for successful treatment of slowly healing neonatal wounds, specifically stage 3 pressure ulcer, dehiscent and infected sternal wound, and full-thickness wound from an extravasation injury.

(2)Maintaining Beauty Through Skin Care(Well-aging-Present State of Rejuvenation Medicine, The 73rd General Meeting of the Society of Tokyo Women's Medical University)

OpenAIRE

川島, 眞; Makoto, KAWASHIMA

2008-01-01

Dry skin, senile freckles and wrinkles are major symptoms of aged skin. Dry skin is caused by the decrease of skin surface lipids, natural moisturizing factors and intercellular lipids of the stratum corneum. Senile freckles are the deposition of melanin pigments on the basal layer of the epidermis which is brought about by the activation of melanocytes through UV exposure and the delay in the turnover rate of epidermal cells due to aging. Wrinkles are caused by UV-induced damage to collagen ...

Identification of antigenic Sarcoptes scabiei proteins for use in a diagnostic test and of non-antigenic proteins that may be immunomodulatory.

OpenAIRE

Marjorie S Morgan; S Dean Rider; Larry G Arlian

2017-01-01

Background Scabies, caused by the mite, Sarcoptes scabiei, infects millions of humans, and many wild and domestic mammals. Scabies mites burrow in the lower stratum corneum of the epidermis of the skin and are the source of substances that are antigenic or modulate aspects of the protective response of the host. Ordinary scabies is a difficult disease to diagnose. Objective The goal of this project was to identify S. scabiei proteins that may be candidate antigens for use in a diagnostic test...

Acral peeling skin syndrome: a case of two brothers.

Science.gov (United States)

Wakade, Oojwala; Adams, Beth; Shwayder, Tor

2009-01-01

We report two brothers of Middle Eastern descent with consanguineous parents who present with numerous fragile, flaccid blisters on the hands and feet. In addition to spontaneous peeling, they can manually peel skin from acral areas without pain. The symptoms worsen with warm temperatures, excessive water exposure, and perspiration. Two biopsies from flaccid blisters on the feet were taken from the older brother, which revealed cleavage at the level of the stratum corneum. A diagnosis of acral peeling skin syndrome was made.

Research and application of multi-hydrogen acidizing technology of low-permeability reservoirs for increasing water injection

Science.gov (United States)

Ning, Mengmeng; Che, Hang; Kong, Weizhong; Wang, Peng; Liu, Bingxiao; Xu, Zhengdong; Wang, Xiaochao; Long, Changjun; Zhang, Bin; Wu, Youmei

2017-12-01

The physical characteristics of Xiliu 10 Block reservoir is poor, it has strong reservoir inhomogeneity between layers and high kaolinite content of the reservoir, the scaling trend of fluid is serious, causing high block injection well pressure and difficulty in achieving injection requirements. In the past acidizing process, the reaction speed with mineral is fast, the effective distance is shorter and It is also easier to lead to secondary sedimentation in conventional mud acid system. On this point, we raised multi-hydrogen acid technology, multi-hydrogen acid release hydrogen ions by multistage ionization which could react with pore blockage, fillings and skeletal effects with less secondary pollution. Multi-hydrogen acid system has advantages as moderate speed, deep penetration, clay low corrosion rate, wet water and restrains precipitation, etc. It can reach the goal of plug removal in deep stratum. The field application result shows that multi-hydrogen acid plug removal method has good effects on application in low permeability reservoir in Block Xiliu 10.

Surfactant-induced skin irritation and skin repair. Evaluation of the acute human irritation model by noninvasive techniques.

Science.gov (United States)

Wilhelm, K P; Freitag, G; Wolff, H H

1994-06-01

Although the induction of irritant dermatitis by surfactants has been extensively studied in recent years, our understanding of the repair phase of irritant dermatitis is limited. We investigated qualitative and quantitative differences in surfactant-induced irritant skin reactions from short-term exposure to three structurally different surfactants. Sodium lauryl sulfate (SLS), dodecyl trimethyl ammonium bromide (DTAB), and potassium soap were the model irritants. Surfactant solutions (0.5%) were applied for 24 hours to the volar aspect of the forearm of 11 volunteers. Irritant reactions were assessed until complete healing was indicated by visual assessment and by various aspects of skin function, that is, transepidermal water loss (TEWL), erythema (skin color reflectance), and stratum that is, transepidermal water loss (TEWL), erythema (skin color reflectance), and stratum corneum hydration (electrical capacitance). SLS and DTAB induced similar degrees of erythema, whereas SLS induced significantly higher TEWL increase. Although both erythema and TEWL were highest 1 hour after exposure to surfactants, skin dryness was a symptom with delayed onset, justifying the long observation period in this study. Minimum hydration values were measured as late as 7 days after surfactant exposure. Dryness was significantly more pronounced in areas exposed to SLS than in areas exposed to DTAB. Complete repair of the irritant reaction induced by either SLS or DTAB was achieved 17 days after surfactant exposure. Stratum corneum hydration was the last feature to return to baseline values. Potassium soap did not significantly influence any skin function. We emphasize the importance of extended periods needed before a patient with irritant contact dermatitis can be reexposed to irritant substances. The evaluation of the irritation potential of diverse surfactants depended significantly on the feature (erythema vs hydration and TEWL) measured.

深厚砂砾石地层固结灌浆在实际工程中的应用%Consolidation Grouting of Deep Sand-gravel Stratum in Practical Engineering Application

Institute of Scientific and Technical Information of China (English)

赵健飞

2014-01-01

水利工程施工过程中，经常会遇到水工建筑物直接修建在砂砾石地层上，为了提高砂砾石地层的整体性、密实性并降低其透水率，一般需要对坝基采取全面的固结灌浆，必要时也在坝基上、下游一定范围内进行固结灌浆。结合水利枢纽的工程实践，对泄洪冲沙闸底板进行全面的固结灌浆处理，施工过程中采用自上而下分段灌浆方法，对现有的钻探与灌浆工艺技术进行优化组合，最终经灌后质量检查，结果满足深厚砂砾石覆盖层固结灌浆的设计要求，取得了良好的效果。%In the construction of hydraulic engineering projects ,the hydraulic structures are often directly built on the sand gravel stratum .In order to improve the integrity of sandy gravel stratum and reduce its permeability ,it is common to apply comprehensive consolidation grouting on the dam foundation ,sometimes consolidation grouting is also carried out in a certain range of the upstream and downstream of the dam foundation when necessary .In the construction of an engineer-ing project ,the comprehensive consolidation grouting was applied on the floor of the outlet sluice with descending stage grouting method during the construction process .This method combined the advantages of the existing drilling and grout-ing techniques and reached a optimum combination .The result of the quality inspection indicates that the outcome not on-ly meets the specifications of consolidation grouting of deep sand gravel stratum ,but also has excellent performance .

Laminated chemical and physical micro-jet actuators based on conductive media

Science.gov (United States)

Gadiraju, Priya D.

2008-04-01

This dissertation presents the development of electrically-powered, lamination-based microactuators for the realization of large arrays of high impulse and short duration micro-jets with potential applications in the field of micro-electro-mechanical systems (MEMS). Microactuators offer unique control opportunities by converting the input electrical or chemical energy stored in a propellant into useful mechanical energy. This small and precise control obtained can potentially be applied towards aerodynamic control and transdermal drug delivery applications. This thesis work discusses the feasibility of using microactuators for two such applications: Control of the motion of a spinning projectile by utilizing the chemically-driven microjets ejected from the actuators, and enhancement of the permeability properties of skin by selectively ablating the stratum corneum layer of skin using the physical microjets ejected from the actuators. This enhanced permeability of skin can later be used for the delivery of high molecular weight drugs for transdermal drug delivery. The development of electrically powered microactuators starts by fabricating an array of radially firing microactuators using lamination-based microfabrication techniques that potentially enable batch fabrication at low cost. The microactuators of this thesis consist of three main parts: a micro chamber in which the propellant is stored; two electrode structures through which electrical energy is supplied to the propellant; and a micro nozzle through which the propellant or released gases from the propellant are expanded as a jet. Once the actuators are fabricated, they are integrated with MEMS-process-compatible propellants and optimized so as to produce instantaneous ignition of the propellant. This instantaneous ignition is achieved either by making the propellant itself conductive, thus, passing an electric current directly through the propellant; or by discharging an arc across the propellant by

Acral peeling skin syndrome resembling epidermolysis bullosa simplex in a 10-month-old boy.

Science.gov (United States)

Kavaklieva, S; Yordanova, I; Bruckner-Tuderman, L; Has, C

2013-01-01

The acral peeling skin syndrome (APSS) is a rare autosomal recessive disorder clinically characterized by asymptomatic desquamation of the skin limited to the hands and feet and histologically by cleavage at the stratum granulosum and stratum corneum level [Kiritsi et al.: J Invest Dermatol 2010;130:1741-1746]. We report on a 10-month-old boy with a history of skin peeling limited to the hands and feet since 2 months of age. Clinical examination revealed erythematous erosions with peripheral desquamation and flaccid blisters. DNA mutation analysis detected two heterozygous TGM5 mutations: c.2T>C, p.M1T in exon 1 and c.337G>T, p.G113C in exon 3 in keeping with the diagnosis of APSS. The clinical presentation of APSS alone might be confusing and strongly resemble epidermolysis bullosa simplex making the differential diagnosis difficult.

Method for reducing heat loss during injection of hot water into an oil stratum

Energy Technology Data Exchange (ETDEWEB)

Evgenev, A E; Kalashnikov, V N; Raiskii, Yu D

1968-07-01

A method is described for reduction of heat loss during the injection of hot water into an oil stratum. During the transportation of the hot water to the face of the bore holes, it has high-molecular polymers added to it. The high-molecular polymer may be guanidine or polyoxyethylene in the quantity of 0.01 to 0.03% by wt.

PHYSICAL AND MECHANICAL PROPERTIES OF Araucaria angustifolia (Bertol. WOOD FOR THREE STRATUM PHYTOSOCIOLOGICAL

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Rafael Beltrame

2010-11-01

Full Text Available The study of physical and mechanical properties of wood is essential for industrial use both in construction and the manufacture of furniture. Thus, the study aimed to determine the physical and mechanical properties of the Araucaria angustifolia wood in terms of three strata phytosociological. For this, 15 trees were felled, five belonging to the upper stratum, the middle stratum five and five for the lower strata. The trees were deployed for the preparation of specimens used for mechanical testing. In the mechanical characterization of the species assays were performed for impact resistance, static bending, compression axial and perpendicular to the fibers. As for the characterization of physical properties, determined the apparent specific gravity at 12% relative humidity for each extract. The results did not show significant differences in the tests of impact resistance and static bending to the strata phytosociological. As for the apparent specific gravity, compression axial and perpendicular there was a change in the values of propertiesbetween the strata phytosociological, is generally butter in the middle and upper strata. Therefore the physical and mechanical properties tend to present higher values these two strata. The data analysis allowed of Araucaria angustifolia wood has moderate mechanical strength when compared with other species studies.

Biokinetics and Biodynamics of Nanomaterial Interactions

Science.gov (United States)

2009-09-30

HEK viability. The medium from each treatment set of the dosed cells was removed, pooled into a microfuge tube , and quickly frozen to -80ºC until...Trump’s fixative at 4ºC. The cells were rinsed in 0.1M phosphate buffer (pH 7.2), pelleted in a microfuge tube , resuspended, and quickly pelleted in 3...formulation on in vitro human skin localized NP in the upper stratum corneum with minimal penetration (Cross et al., 2007) and microfine zinc oxide with a

Performance evaluation of multi-stratum resources optimization with network functions virtualization for cloud-based radio over optical fiber networks.

Science.gov (United States)

Yang, Hui; He, Yongqi; Zhang, Jie; Ji, Yuefeng; Bai, Wei; Lee, Young

2016-04-18

Cloud radio access network (C-RAN) has become a promising scenario to accommodate high-performance services with ubiquitous user coverage and real-time cloud computing using cloud BBUs. In our previous work, we implemented cross stratum optimization of optical network and application stratums resources that allows to accommodate the services in optical networks. In view of this, this study extends to consider the multiple dimensional resources optimization of radio, optical and BBU processing in 5G age. We propose a novel multi-stratum resources optimization (MSRO) architecture with network functions virtualization for cloud-based radio over optical fiber networks (C-RoFN) using software defined control. A global evaluation scheme (GES) for MSRO in C-RoFN is introduced based on the proposed architecture. The MSRO can enhance the responsiveness to dynamic end-to-end user demands and globally optimize radio frequency, optical and BBU resources effectively to maximize radio coverage. The efficiency and feasibility of the proposed architecture are experimentally demonstrated on OpenFlow-based enhanced SDN testbed. The performance of GES under heavy traffic load scenario is also quantitatively evaluated based on MSRO architecture in terms of resource occupation rate and path provisioning latency, compared with other provisioning scheme.

Enantioselective skin permeation of ibuprofen enantiomers: mechanistic insights from ATR-FTIR and CLSM studies based on synthetic enantiomers as naphthalimide fluorescent probes.

Science.gov (United States)

Che, Qi-en; Quan, Peng; Mu, Mao; Zhang, Xinfu; Zhao, Hanqing; Zhang, Yu; You, Song; Xiao, Yi; Fang, Liang

2014-10-01

The aim of this study was to investigate the mechanisms of different skin permeability of ibuprofen racemate and enantiomers. The percutaneous permeation of ibuprofen racemate and enantiomers through rabbit normal skin and damaged skin (without stratum corneum [SC]) was investigated in vitro using side-by-side diffusion cells. With the melting temperature-membrane transport model, the flux ratio of enantiomer/racemate was calculated from their thermodynamic properties obtained by differential scanning calorimetry. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) study was performed to evaluate the interaction between the enantiomers and the SC. New fluorescent probes were designed and utilized in confocal laser scanning microscopy (CLSM) study for visualization of the enantioselective permeation of the enantiomers through the intact rabbit skin. The flux of (S)-ibuprofen through normal skin was significantly higher than that of (RS)-ibuprofen and (R)-ibuprofen (p skin, there was no significant difference (p > 0.05). The predicted flux ratio of (S)-ibuprofen/(RS)-ibuprofen (2.50) was in close agreement with the experimentally determined ratio (2.48). These results were supported by ATR-FTIR and CLSM studies that indicated that a chiral environment of the skin led to the enantioselective permeation of enantiomers. The chiral nature of the SC and the different physicochemical properties of the enantiomers should be taken into account in the assessment of different skin permeability of the racemate and enantiomers. The synthetic fluorescent probes used in this study could visualize the enantioselective permeation of the chiral compounds across the skin.

The influence of water mixtures on the dermal absorption of glycol ethers

International Nuclear Information System (INIS)

Traynor, Matthew J.; Wilkinson, Simon C.; Williams, Faith M.

2007-01-01

Glycol ethers are solvents widely used alone and as mixtures in industrial and household products. Some glycol ethers have been shown to have a range of toxic effects in humans following absorption and metabolism to their aldehyde and acid metabolites. This study assessed the influence of water mixtures on the dermal absorption of butoxyethanol and ethoxyethanol in vitro through human skin. Butoxyethanol penetrated human skin up to sixfold more rapidly from aqueous solution (50%, 450 mg/ml) than from the neat solvent. Similarly penetration of ethoxyethanol was increased threefold in the presence of water (50%, 697 mg/ml). There was a corresponding increase in apparent permeability coefficient as the glycol ether concentration in water decreased. The maximum penetration rate of water also increased in the presence of both glycol ethers. Absorption through a synthetic membrane obeyed Fick's Law and absorption through rat skin showed a similar profile to human skin but with a lesser effect. The mechanisms for this phenomenon involves disruption of the stratum corneum lipid bilayer by desiccation by neat glycol ether micelles, hydration with water mixtures and the physicochemical properties of the glycol ether-water mixtures. Full elucidation of the profile of absorption of glycol ethers from mixtures is required for risk assessment of dermal exposure. This work supports the view that risk assessments for dermal contact scenarios should ideally be based on absorption data obtained for the relevant formulation or mixture and exposure scenario and that absorption derived from permeability coefficients may be inappropriate for water-miscible solvents

Construction of horizontal stratum landform-like composite foams and their methyl orange adsorption capacity

International Nuclear Information System (INIS)

Chen, Jiajia; Shi, Xiaowen; Zhan, Yingfei; Qiu, Xiaodan; Du, Yumin; Deng, Hongbing

2017-01-01

Highlights: • CS/REC/CNTs composite foams were prepared by unidirectional freeze-casting. • Horizontal stratum landform-like structure was successful built up in foam. • The addition of REC and CNTs promoted the mechanical properties of foam. • The introduction of REC and CNTs enhanced the adsorption capacity of foam on dye. - Abstract: Chitosan (CS)/rectorite (REC)/carbon nanotubes (CNTs) composite foams with good mechanical properties were successfully fabricated by unidirectional freeze-casting technique. The morphology of the foam showed the well-ordered porous three-dimensional layers and horizontal stratum landform-like structure. The holes on the layers looked like the wings of butterfly. Additionally, the X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy results indicated the successful addition of CNTs and REC. The intercalated REC with CS chains was confirmed by small-angle X-ray diffraction. The surface structure of the foams was also analyzed by Raman spectroscopy. The adsorption experiments showed that when the mass ratio of CS to REC was 10:1 and CNTs content was 20%, the composite foam performed best in adsorbing low concentration methyl orange, and the largest adsorption capacity was 41.65 mg/g.

Construction of horizontal stratum landform-like composite foams and their methyl orange adsorption capacity

Energy Technology Data Exchange (ETDEWEB)

Chen, Jiajia; Shi, Xiaowen; Zhan, Yingfei; Qiu, Xiaodan; Du, Yumin; Deng, Hongbing, E-mail: hbdeng@whu.edu.cn

2017-03-01

Highlights: • CS/REC/CNTs composite foams were prepared by unidirectional freeze-casting. • Horizontal stratum landform-like structure was successful built up in foam. • The addition of REC and CNTs promoted the mechanical properties of foam. • The introduction of REC and CNTs enhanced the adsorption capacity of foam on dye. - Abstract: Chitosan (CS)/rectorite (REC)/carbon nanotubes (CNTs) composite foams with good mechanical properties were successfully fabricated by unidirectional freeze-casting technique. The morphology of the foam showed the well-ordered porous three-dimensional layers and horizontal stratum landform-like structure. The holes on the layers looked like the wings of butterfly. Additionally, the X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy results indicated the successful addition of CNTs and REC. The intercalated REC with CS chains was confirmed by small-angle X-ray diffraction. The surface structure of the foams was also analyzed by Raman spectroscopy. The adsorption experiments showed that when the mass ratio of CS to REC was 10:1 and CNTs content was 20%, the composite foam performed best in adsorbing low concentration methyl orange, and the largest adsorption capacity was 41.65 mg/g.

Effect of Ceramide Tail Length on the Structure of Model Stratum Corneum Lipid Bilayers.

Science.gov (United States)

Moore, Timothy C; Hartkamp, Remco; Iacovella, Christopher R; Bunge, Annette L; McCabe, Clare

2018-01-09

Lipid bilayers composed of non-hydroxy sphingosine ceramide (CER NS), cholesterol (CHOL), and free fatty acids (FFAs), which are components of the human skin barrier, are studied via molecular dynamics simulations. Since mixtures of these lipids exist in dense gel phases with little molecular mobility at physiological conditions, care must be taken to ensure that the simulations become decorrelated from the initial conditions. Thus, we propose and validate an equilibration protocol based on simulated tempering, in which the simulation takes a random walk through temperature space, allowing the system to break out of metastable configurations and hence become decorrelated from its initial configuration. After validating the equilibration protocol, which we refer to as random-walk molecular dynamics, the effects of the lipid composition and ceramide tail length on bilayer properties are studied. Systems containing pure CER NS, CER NS + CHOL, and CER NS + CHOL + FFA, with the CER NS fatty acid tail length varied within each CER NS-CHOL-FFA composition, are simulated. The bilayer thickness is found to depend on the structure of the center of the bilayer, which arises as a result of the tail-length asymmetry between the lipids studied. The hydrogen bonding between the lipid headgroups and with water is found to change with the overall lipid composition, but is mostly independent of the CER fatty acid tail length. Subtle differences in the lateral packing of the lipid tails are also found as a function of CER tail length. Overall, these results provide insight into the experimentally observed trend of altered barrier properties in skin systems where there are more CERs with shorter tails present. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Notional Permeability

NARCIS (Netherlands)

Kik, R.; Van den Bos, J.P.; Maertens, J.; Verhagen, H.J.; Van der Meer, J.W.

2012-01-01

Different layer design of a rock slope and under layers has a large effect on the strengths on the rock slope itself. In the stability formula developed of VAN DER MEER [1988] this effect is represented by the term Notional Permeability with symbol P. A more open, or permeable, structure underneath

High-permeability criterion for BCS classification: segmental/pH dependent permeability considerations.

Science.gov (United States)

Dahan, Arik; Miller, Jonathan M; Hilfinger, John M; Yamashita, Shinji; Yu, Lawrence X; Lennernäs, Hans; Amidon, Gordon L

2010-10-04

The FDA classifies a drug substance as high-permeability when the fraction of dose absorbed (F(abs)) in humans is 90% or higher. This direct correlation between human permeability and F(abs) has been recently controversial, since the β-blocker sotalol showed high F(abs) (90%) and low Caco-2 permeability. The purpose of this study was to investigate the scientific basis for this disparity between permeability and F(abs). The effective permeabilities (P(eff)) of sotalol and metoprolol, a FDA standard for the low/high P(eff) class boundary, were investigated in the rat perfusion model, in three different intestinal segments with pHs corresponding to the physiological pH in each region: (1) proximal jejunum, pH 6.5; (2) mid small intestine, pH 7.0; and (3) distal ileum, pH 7.5. Both metoprolol and sotalol showed pH-dependent permeability, with higher P(eff) at higher pH. At any given pH, sotalol showed lower permeability than metoprolol; however, the permeability of sotalol determined at pH 7.5 exceeded/matched metoprolol's at pH 6.5 and 7.0, respectively. Physicochemical analysis based on ionization, pK(a) and partitioning of these drugs predicted the same trend and clarified the mechanism behind these observed results. Experimental octanol-buffer partitioning experiments confirmed the theoretical curves. An oral dose of metoprolol has been reported to be completely absorbed in the upper small intestine; it follows, hence, that metoprolol's P(eff) value at pH 7.5 is not likely physiologically relevant for an immediate release dosage form, and the permeability at pH 6.5 represents the actual relevant value for the low/high permeability class boundary. Although sotalol's permeability is low at pH 6.5 and 7.0, at pH 7.5 it exceeds/matches the threshold of metoprolol at pH 6.5 and 7.0, most likely responsible for its high F(abs). In conclusion, we have shown that, in fact, there is no discrepancy between P(eff) and F(abs) in sotalol's absorption; the data emphasize that

Random selection of items. Selection of n1 samples among N items composing a stratum

International Nuclear Information System (INIS)

Jaech, J.L.; Lemaire, R.J.

1987-02-01

STR-224 provides generalized procedures to determine required sample sizes, for instance in the course of a Physical Inventory Verification at Bulk Handling Facilities. The present report describes procedures to generate random numbers and select groups of items to be verified in a given stratum through each of the measurement methods involved in the verification. (author). 3 refs

Microneedles for intradermal and transdermal delivery

Science.gov (United States)

Tuan-Mahmood, Tuan-Mazlelaa; McCrudden, Maeliosa T.C.; Torrisi, Barbara M.; McAlister, Emma; Garland, Martin J; Singh, Thakur Raghu Raj; Donnelly, Ryan F

2014-01-01

The formidable barrier properties of the uppermost layer of the skin, the stratum corneum impose significant limitations for successful systemic delivery of a broad range of therapeutic molecules, particularly macromolecules and genetic material. Microneedle delivery has been proposed as a strategy to breach the SC barrier function in order to facilitate effective transport of molecules across the skin. This strategy involves the use of micron sized needles fabricated from different materials and using different geometries to create transient aqueous conduits across the skin. Microneedles in isolation, or in combination with other enhancing strategies, have been shown to dramatically enhance the skin permeability of numerous therapeutic molecules including biopharmaceuticals either in vitro, ex vivo or in vivo. Progress in the areas of microneedle design, development and manufacture have proven promising in terms of the potential use of this emerging delivery method in clinical applications such as insulin delivery, transcutaneous immunisations and cutaneous gene delivery. This review article focuses on recent and potential future developments in microneedle technologies. This will include the detailing of progress made in microneedle design, an exploration of the challenges faced in this field and potential forward strategies to embrace the exploitation of microneedle methodologies, while considering the inherent safety aspects of such therapeutic tools. PMID:23680534

Enhancing topical analgesic administration: review and prospect for transdermal and transbuccal drug delivery systems.

Science.gov (United States)

Sanz, Roser; Calpena, Ana C; Mallandrich, Mireia; Clares, Beatriz

2015-01-01

Topical administration is an appealing method for drug delivery due to its non-invasiveness, self-controlled application, avoidance of first-pass metabolism in the liver and reduction of systemic side effects compared to other conventional routes such as oral and parenteral. However, topical administration must overcome the permeable barriers that skin and mucosa represent for the drug to achieve its desired therapeutic effect. Penetration of drugs through human skin is mainly impaired by the stratum corneum- the uppermost keratinized skin layer. In contrast, the stratified squamous epithelium (a nonkeratinized tissue) represents the major physical barrier for transbuccal drug administration in humans. Different technologies have been studied to enhance the bioavailability or local effects of drugs administered through skin and buccal mucosa. Those technologies involve the use of physical or chemical enhancers and new dosage forms such as vesicles, cyclodextrins, nanoparticles and other complex systems. Combinations of these technologies may further increase drug delivery in some cases. As analgesia is one of the main therapeutic effects sought through topical administration, this paper focuses on the review of drug delivery systems to improve the topical and transdermal/transbuccal drug delivery of substances with known analgesic action. A discussion of their possibilities and limitations is also included.

Sebaceous Gland, Hair Shaft, and Epidermal Barrier Abnormalities in Keratosis Pilaris with and without Filaggrin Deficiency

Science.gov (United States)

Gruber, Robert; Sugarman, Jeffrey L.; Crumrine, Debra; Hupe, Melanie; Mauro, Theodora M.; Mauldin, Elizabeth A.; Thyssen, Jacob P.; Brandner, Johanna M.; Hennies, Hans-Christian; Schmuth, Matthias; Elias, Peter M.

2016-01-01

Although keratosis pilaris (KP) is common, its etiopathogenesis remains unknown. KP is associated clinically with ichthyosis vulgaris and atopic dermatitis and molecular genetically with filaggrin-null mutations. In 20 KP patients and 20 matched controls, we assessed the filaggrin and claudin 1 genotypes, the phenotypes by dermatoscopy, and the morphology by light and transmission electron microscopy. Thirty-five percent of KP patients displayed filaggrin mutations, demonstrating that filaggrin mutations only partially account for the KP phenotype. Major histologic and dermatoscopic findings of KP were hyperkeratosis, hypergranulosis, mild T helper cell type 1-dominant lymphocytic inflammation, plugging of follicular orifices, striking absence of sebaceous glands, and hair shaft abnormalities in KP lesions but not in unaffected skin sites. Changes in barrier function and abnormal paracellular permeability were found in both interfollicular and follicular stratum corneum of lesional KP, which correlated ultrastructurally with impaired extracellular lamellar bilayer maturation and organization. All these features were independent of filaggrin genotype. Moreover, ultrastructure of corneodesmosomes and tight junctions appeared normal, immunohistochemistry for claudin 1 showed no reduction in protein amounts, and molecular analysis of claudin 1 was unremarkable. Our findings suggest that absence of sebaceous glands is an early step in KP pathogenesis, resulting in downstream hair shaft and epithelial barrier abnormalities. PMID:25660180

Evaluation of the mechanism of skin enhancing surfactants on the biomembrane of shed snake skin.

Science.gov (United States)

Wonglertnirant, Nanthida; Ngawhirunpat, Tanasait; Kumpugdee-Vollrath, Mont

2012-01-01

The aim of the present work was to investigate the effects of different surfactants at various concentrations as a skin penetration enhancer through the biomembrane of the shed skin of Naja kaouthia. Additionally, the enhancer mechanism(s) of each class of surfactants were evaluated using physical characterization techniques, such as scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and small and wide angle X-ray scattering (SWAXS). Our results showed that skin permeability increased with increasing concentrations of surfactants and the degree of increase was higher for the model hydrophilic permeant, deuterium dioxide (D(2)O), than the lipophilic permeant, ketoprofen (KP). Ionic surfactants, sodium lauryl sulfate (SLS) and cetyl trimethyl ammonium bromide (CTAB), demonstrated higher enhancement ability than the polyoxyethylene (20) sorbitan mono-oleate (Tween 80) non-ionic surfactant, which was consistent with the results from physical characterization studies. Increasing amounts of permeated drug resulted in an increase in membrane interactions. From our observations, it can be assumed that SLS and CTAB can be localized inside the biomembrane and thereby enhance drug permeation mainly through interactions with intercellular lipids in the stratum corneum (SC) and the creation of a perturbed microenvironment among lipid alkyl chains and polar head groups.

Hydration Effects on Skin Microstructure as Probed by High-Resolution Cryo-Scanning Electron Microscopy and Mechanistic Implications to Enhanced Transcutaneous Delivery of Biomacromolecules

Science.gov (United States)

Tan, Grace; Xu, Peng; Lawson, Louise B.; He, Jibao; Freytag, Lucia C.; Clements, John D.; John, Vijay T.

2010-01-01

Although hydration is long known to improve the permeability of skin, penetration of macromolecules such as proteins is limited and the understanding of enhanced transport is based on empirical observations. This study uses high-resolution cryo-scanning electron microscopy to visualize microstructural changes in the stratum corneum (SC) and enable a mechanistic interpretation of biomacromolecule penetration through highly hydrated porcine skin. Swollen corneocytes, separation of lipid bilayers in the SC intercellular space to form cisternae, and networks of spherical particulates are observed in porcine skin tissue hydrated for a period of 4–10 h. This is explained through compaction of skin lipids when hydrated, a reversal in the conformational transition from unilamellar liposomes in lamellar granules to lamellae between keratinocytes when the SC skin barrier is initially established. Confocal microscopy studies show distinct enhancement in penetration of fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) through skin hydrated for 4–10 h, and limited penetration of FITC-BSA once skin is restored to its natively hydrated structure when exposed to the environment for 2–3 h. These results demonstrate the effectiveness of a 4–10 h hydration period to enhance transcutaneous penetration of large biomacromolecules without permanently damaging the skin. PMID:19582754

Comparative behavior between sunscreens based on free or encapsulated UV filters in term of skin penetration, retention and photo-stability.

Science.gov (United States)

Cozzi, Arianna C; Perugini, Paola; Gourion-Arsiquaud, Samuel

2018-06-03

The growing incidence of photodamaging effects caused by UV radiation (e.g. sunburn, skin cancer) has increased the attention from health authorities which recommend the topical application of sunscreens to prevent these skin damages. The economic stakes for those companies involved in this international market are to develop new UV filters and innovative technologies to provide the most efficient, flexible and robust sunscreen products. Today the development of innovative and competitive sunscreen products is a complex formulation challenge. Indeed, the current sunscreens must protect against skin damages, while also being safe for the skin and being sensory and visually pleasant for the customers when applied on the skin. Organic UV filters, while proposing great advantages, also present the risk to penetrate the stratum corneum and diffuse into underlying structures with unknown consequences; moreover, their photo-stability are noted thorny outcomes in sunscreen development and subsequent performance. In recent years, the evaluation of the interaction between skin and sunscreen in terms of penetration after topical application has been considered from European authority but still its testing as their photo-stability assessment are not mandatory in most countries. This study, based on in-vitro approaches, was performed to evaluate and compare the retention and the penetration of organic UV filters in free or encapsulated form inside the skin as well as their respective photo-stability. Sunscreen formulation with a combination of Avobenzone and Octocrylene in "free form" and a formulation using the same UV filters but encapsulated in a sol-gel silica capsule, were analyzed and compared by FTIR Imaging Spectroscopy. Tape stripping method was used to investigate the penetration of these UV filters inside the stratum corneum. Their photo-stabilities were evaluated by spectroscopic measurements (FTIR, UV/Vis) and standard measurements were calculated: AUC (Area Under

Application of a non-invasive method to study the moisturizing effect of formulations containing vitamins A or E or ceramide on human skin.

Science.gov (United States)

Leonardi, Gislaine Ricci; Gaspar, Lorena Rigo; Maia Campos, Patrícia M B G

2002-01-01

Moisturizers containing vitamins A and E as well as ceramides are believed to improve the skin condition by increasing the water content of the stratum corneum. The aim of this research was to evaluate, through the capacitance method (a non-invasive method), the moisturizing effect of an O/W emulsion (non-ionic self-emulsifying base) containing vitamin A palmitate, vitamin E acetate, and ceramide III on human skin. The studies were carried out on a group of 40 healthy Caucasian female test subjects between 30 and 45 years of age, using the Corneometer CM 825 PC. Skin measurements were taken from the volunteers at 7 and 30 days after daily use (twice a day) of the tested products. The presence of vitamins A and E or ceramide III did not cause an improvement in the hydration of the stratum corneum, which means that none of those compounds strengthens the hydration effectiveness of the base formulations used, at least at the doses tested. The interpretation of electrical measurement regarding skin moisture should be made with caution; thus the results observed in this study show the importance of using different approaches (or methodologies) to verify the performance of the formulas tested. We conclude that, at the low doses typically used in cosmetic formulations, vitamins A and E and ceramide III are not likely to contribute to the hydrating effects of the base moisturizing formulation when assessed by capacitance.

Comparative instrumental evaluation of efficacy and safety between a binary and a ternary system in chemexfoliation.

Science.gov (United States)

Cameli, Norma; Mariano, Maria; Ardigò, Marco; Corato, Cristina; De Paoli, Gianfranco; Berardesca, Enzo

2017-09-20

To instrumentally evaluate the efficacy and the safety of a new ternary system chemo exfoliating formulation (water-dimethyl isosorbide-acid) vs traditional binary systems (water and acid) where the acid is maintained in both the systems at the same concentration. Different peelings (binary system pyruvic acid and trichloroacetic acid-TCA, and ternary system pyruvic acid and TCA) were tested on the volar forearm of 20 volunteers of both sexes between 28 and 50 years old. The outcomes were evaluated at the baseline, 10 minutes, 24 hours, and 1 week after the peeling by means of noninvasive skin diagnosis techniques. In vivo reflectance confocal microscopy was used for stratum corneum evaluation, transepidermal waterloss, and Corneometry for skin barrier and hydration, Laser Doppler velocimetry in association with colorimetry for irritation and erythema analysis. The instrumental data obtained showed that the efficacy and safety of the new ternary system peel compounds were significantly higher compared with the binary system formulations tested. The new formulation peels improved chemexfoliation and reduced complications such as irritation, redness, and postinflammatory pigmentation compared to the traditional aqueous solutions. The study showed that ternary system chemexfoliation, using a controlled delivery technology, was able to provide the same clinical effects in term of stratum corneum reduction with a significantly reduced barrier alteration, water loss, and irritation/erythema compared to traditional binary system peels. © 2017 Wiley Periodicals, Inc.

Effect of skin barrier disruption on immune responses to topically applied cross-reacting material, CRM(197), of diphtheria toxin.

Science.gov (United States)

Godefroy, S; Peyre, M; Garcia, N; Muller, S; Sesardic, D; Partidos, C D

2005-08-01

The high accessibility of the skin and the presence of immunocompetent cells in the epidermis makes this surface an attractive route for needle-free administration of vaccines. However, the lining of the skin by the stratum corneum is a major obstacle to vaccine delivery. In this study we examined the effect of skin barrier disruption on the immune responses to the cross-reacting material CRM(197), a nontoxic mutant of diphtheria toxin (DTx) that is considered as a vaccine candidate. Application of CRM(197), together with cholera toxin (CT), onto the tape-stripped skin of mice elicited antibody responses that had anti-DTx neutralizing activity. Vaccine delivery onto mildly ablated skin or intact skin did not elicit any detectable anti-CRM(197) antibodies. Mice immunized with CRM(197) alone onto the tape-stripped skin mounted a vigorous antigen-specific proliferative response. In contrast, the induction of cellular immunity after CRM(197) deposition onto mildly ablated or intact skin was adjuvant dependent. Furthermore, epidermal cells were activated and underwent apoptosis that was more pronounced when the stratum corneum was removed by tape stripping. Overall, these findings highlight the potential for transcutaneous delivery of CRM(197) and establish a correlation between the degree of barrier disruption and levels of antigen-specific immune responses. Moreover, these results provide the first evidence that the development of a transcutaneous immunization strategy for diphtheria, based on simple and practical methods to disrupt the skin barrier, is feasible.

Oral administration of Bifidobacterium breve attenuates UV-induced barrier perturbation and oxidative stress in hairless mice skin.

Science.gov (United States)

Ishii, Yuki; Sugimoto, Saho; Izawa, Naoki; Sone, Toshiro; Chiba, Katsuyoshi; Miyazaki, Kouji

2014-07-01

Recent studies have shown that some probiotics affect not only the gut but also the skin. However, the effects of probiotics on ultraviolet (UV)-induced skin damage are poorly understood. In this study, we aim to examine whether oral administration of live Bifidobacterium breve strain Yakult (BBY), a typical probiotic, can attenuate skin barrier perturbation caused by UV and reactive oxygen species (ROS) in hairless mice. The mice were orally supplemented with a vehicle only or BBY once a day for nine successive days. Mouse dorsal skin was irradiated with UV from days 6 to 9. The day after the final irradiation, the transepidermal water loss (TEWL), stratum corneum hydration, and oxidation-related factors of the skin were evaluated. We elucidated that BBY prevented the UV-induced increase in TEWL and decrease in stratum corneum hydration. In addition, BBY significantly suppressed the UV-induced increase in hydrogen peroxide levels, oxidation of proteins and lipids, and xanthine oxidase activity in the skin. Conversely, antioxidant capacity did not change regardless of whether BBY was administered or not. In parameters we evaluated, there was a positive correlation between the increase in TEWL and the oxidation levels of proteins and lipids. Our results suggest that oral administration of BBY attenuates UV-induced barrier perturbation and oxidative stress of the skin, and this antioxidative effect is not attributed to enhancement of antioxidant capacity but to the prevention of ROS generation.

Circumscribed palmar or plantar hypokeratosis 10 years after the first description: what is known and the issues under discussion.

Science.gov (United States)

Urbina, F; Pérez, A; Requena, L; Rütten, A

2014-01-01

This review of the literature on palmoplantar hypokeratosis, a process that was first indentified only 10 years ago, discusses the current state of our understanding, the therapeutic options available, and the debate about etiology. Forty-four publications reporting 69 cases were found. Palmar or plantar hypokeratosis occurs mainly in women (76.8%) and age at the time of a first visit to a physician ranges from 42 to 84 years. Most cases present between the ages of 51 and 70 years. The majority of patients have had solitary lesions usually located on the right palm, particularly in the regions of the thenar (in 44/79 lesions [55.7%]) or hypothenar eminences (in 11/79 lesions [13.9%]). In only 8 cases was there a history of prior trauma at the site. Studies using polymerase chain reaction techniques to identify human papillomavirus involvement were negative in most cases. These hypokeratotic lesions are localized epidermal depressions formed by an abrupt thinning of the stratum corneum, providing a singular histopathologic feature. This condition can currently be considered a localized keratinization disorder affecting zones where there is a thick stratum corneum. The precipitating cause is unknown and a definitive treatment remains to be found. The mechanism would be the localized failure of a clone of keratinocytes during differentiation toward normal palmoplantar hyperkeratinization. Copyright © 2012 Elsevier España, S.L. y AEDV. All rights reserved.

Permeability measuremens of brazilian Eucalyptus

Directory of Open Access Journals (Sweden)

Marcio Rogério da Silva

2010-09-01

Full Text Available The permeability of Brazilian Eucalyptus grandis and Eucalyptus citriodora wood was measured in a custom build gas analysis chamber in order to determine which species could be successfully treated with preservatives. Liquid permeability was tested using an emulsion of Neen oil and a control of distillated water. Air was used to test the gas phase permeability. For both Eucalyptus grandis and Eucalyptus citriodora, the longitudinal permeability of gas was shown to be about twice as great as the liquid phase permeability. No radial permeability was observed for either wood. The permeability of air and water through the sapwood of Eucalyptus grandis was greater than that through the sapwood of Eucalyptus citriodora. The permeability of neen oil preservative through the sapwood of Eucalyptus grandis was also greater than through the sapwood of E. Citradora, but the difference was not statistically significant. Scanning Electron Microscopy images showed that the distribution and obstruction in the vessels could be correlated with observed permeability properties. Irrespective of the causes of differences in permeability between the species, the fluid phase flux through the sapwood of both species was significant, indicating that both Eucalyptus grandis and Eucalyptus citriodora could be successfully treated with wood preservative.

Intestinal Permeability: The Basics

Directory of Open Access Journals (Sweden)

Ingvar Bjarnason

1995-01-01

Full Text Available The authors review some of the more fundamental principles underlying the noninvasive assessment of intestinal permeability in humans, the choice of test markers and their analyses, and the practical aspects of test dose composition and how these can be changed to allow the specific assessment of regional permeability changes and other intestinal functions. The implications of increased intestinal permeability in the pathogenesis of human disease is discussed in relation to findings in patients with Crohn’s disease. A common feature of increased intestinal permeability is the development of a low grade enteropathy, and while quantitatively similar changes may be found in Crohn’s disease these seem to predict relapse of disease. Moreover, factors associated with relapse of Crohn’s disease have in common an action to increase intestinal permeability. While increased intestinal permeability does not seem to be important in the etiology of Crohn’s disease it may be a central mechanism in the clinical relapse of disease.

Experimental study of airflow characteristics of stratum ventilation in a multi-occupant room with comparison to mixing ventilation and displacement ventilation.

Science.gov (United States)

Cheng, Y; Lin, Z

2015-12-01

The motivation of this study is stimulated by a lack of knowledge about the difference of airflow characteristics between a novel air distribution method [i.e., stratum ventilation (SV)] and conventional air distribution methods [i.e., mixing ventilation (MV) and displacement ventilation (DV)]. Detailed air velocity and temperature measurements were conducted in the occupied zone of a classroom with dimensions of 8.8 m (L) × 6.1 m (W) × 2.4 m (H). Turbulence intensity and power spectrum of velocity fluctuation were calculated using the measured data. Thermal comfort and cooling efficiency were also compared. The results show that in the occupied zone, the airflow characteristics among MV, DV, and SV are different. The turbulent airflow fluctuation is enhanced in this classroom with multiple thermal manikins due to thermal buoyancy and airflow mixing effect. Thermal comfort evaluations indicate that in comparison with MV and DV, a higher supply air temperature should be adopted for SV to achieve general thermal comfort with low draft risk. Comparison of the mean air temperatures in the occupied zone reveals that SV is of highest cooling efficiency, followed by DV and then MV. This study reports the unique profiles of flow, temperature, turbulence intensity, and power spectrum of stratum ventilation, which can have a number of implications for both knowledge and understanding of the flow characteristics in a stratum-ventilated room. With respect to the former, it expounds the fundamental characteristics of this air distribution method; and with respect to the latter, it reveals the mechanism of thermal comfort and energy saving under stratum ventilation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Hierarchical nitrogen-doped porous carbon with high surface area derived from endothelium corneum gigeriae galli for high-performance supercapacitor

International Nuclear Information System (INIS)

Hong, Xiaoting; Hui, K.S.; Zeng, Zhi; Hui, K.N.; Zhang, Luojiang; Mo, Mingyue; Li, Min

2014-01-01

Highlights: • Porous carbons were prepared using endothelium corneum gigeriae galli as precursor. • Surface and structural properties strongly depend on carbonization temperatures. • Resultant carbons possess nitrogen heteroatom and high surface areas. • ECGG-900 sample exhibits excellent electrochemical capacitive performances. - Abstract: Endothelium corneum gigeriae galli derived 3D hierarchical nitrogen-doped porous carbon was for the first time prepared by preliminary carbonization at 450 °C and final KOH activation at high temperatures. The surface and structural properties of the as-synthesized samples are analyzed with Brunauer–Emmett–Teller surface analyzer apparatus, X-Ray Diffractometer, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectrometer. The electrochemical performances are analyzed by cyclic voltammetry, galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy. The obtained results show that the sample carbonized at 900 °C possesses the SSA of 2149.9 m 2 g −1 , average micropore diameter of 1.78 nm, and exhibits the highest initial specific capacitance of 198.0 F g −1 at current density of 1 A g −1 in 6 M KOH solution. It retains good specific capacitance retention of 91.6% after 3000 charge/discharge cycles at current density of 2 A g −1

Effects of topical corticosteroid and tacrolimus on ceramides and irritancy to sodium lauryl sulphate in healthy skin

DEFF Research Database (Denmark)

Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellegren, Lars I

2011-01-01

twice daily for one week with betamethasone, tacrolimus, emollient, or left untreated, respectively. After one week each area was challenged with a 24 h sodium lauryl sulphate patch test. The lipids were collected using the cyanoacrylate method and evaluated by high performance thin layer chromatography......The skin barrier, located in the stratum corneum, is influenced mainly by the lipid and protein composition of this layer. In eczematous diseases impairment of the skin barrier is thought to be of prime importance. Topical anti-inflammatory drugs and emollients are the most widely used eczema...

Undulating tubular liposomes through incorporation of a synthetic skin ceramide into phospholipid bilayers.

Science.gov (United States)

Xu, Peng; Tan, Grace; Zhou, Jia; He, Jibao; Lawson, Louise B; McPherson, Gary L; John, Vijay T

2009-09-15

Nonspherical liposomes were prepared by doping L-alpha-phosphatidylcholine (PC) with ceramide VI (a skin lipid). Cryo-transmission electron microscopy shows the liposome shape changing from spherical to an undulating tubular morphology, when the amount of ceramide VI is increased. The formation of tubular liposomes is energetically favorable and is attributed to the association of ceramide VI with PC creating regions of lower curvature. Since ceramides are the major component of skin lipids in the stratum corneum, tubular liposomes containing ceramide may potentially serve as self-enhanced nanocarriers for transdermal delivery.

Skin fluorescence model based on the Monte Carlo technique

Science.gov (United States)

Churmakov, Dmitry Y.; Meglinski, Igor V.; Piletsky, Sergey A.; Greenhalgh, Douglas A.

2003-10-01

The novel Monte Carlo technique of simulation of spatial fluorescence distribution within the human skin is presented. The computational model of skin takes into account spatial distribution of fluorophores following the collagen fibers packing, whereas in epidermis and stratum corneum the distribution of fluorophores assumed to be homogeneous. The results of simulation suggest that distribution of auto-fluorescence is significantly suppressed in the NIR spectral region, while fluorescence of sensor layer embedded in epidermis is localized at the adjusted depth. The model is also able to simulate the skin fluorescence spectra.

Ceramides and barrier function in healthy skin

DEFF Research Database (Denmark)

Jungerstedt, J; Hellgren, Lars; Drachmann, Tue

2010-01-01

Lipids in the stratum corneum are key components in the barrier function of the skin. Changes in lipid composition related to eczematous diseases are well known, but limited data are available on variations within healthy skin. The objective of the present study was to compare ceramide subgroups...... and ceramide/cholesterol ratios in young, old, male and female healthy skin. A total of 55 participants with healthy skin was included in the study. Lipid profiles were correlated with transepidermal water loss and with information on dry skin from a questionnaire including 16 people. No statistically...

Causes of epidermal filaggrin reduction and their role in the pathogenesis of atopic dermatitis

DEFF Research Database (Denmark)

Thyssen, Jacob P; Kezic, Sanja

2014-01-01

contribute to stratum corneum hydration and pH. The levels of filaggrin and its degradation products are influenced not only by the filaggrin genotype but also by inflammation and exogenous stressors. Pertinently, filaggrin deficiency is observed in patients with atopic dermatitis regardless of filaggrin...... mutation status, suggesting that the absence of filaggrin is a key factor in the pathogenesis of this skin condition. In this article we review the various causes of low filaggrin levels, centralizing the functional and morphologic role of a deficiency in filaggrin, its metabolites, or both...

Acral Peeling Skin Syndrome Resembling Epidermolysis Bullosa Simplex in a 10-Month-Old Boy

Directory of Open Access Journals (Sweden)

S. Kavaklieva

2013-08-01

Full Text Available The acral peeling skin syndrome (APSS is a rare autosomal recessive disorder clinically characterized by asymptomatic desquamation of the skin limited to the hands and feet and histologically by cleavage at the stratum granulosum and stratum corneum level [Kiritsi et al.: J Invest Dermatol 2010;130:1741-1746]. We report on a 10-month-old boy with a history of skin peeling limited to the hands and feet since 2 months of age. Clinical examination revealed erythematous erosions with peripheral desquamation and flaccid blisters. DNA mutation analysis detected two heterozygous TGM5 mutations: c.2T>C, p.M1T in exon 1 and c.337G>T, p.G113C in exon 3 in keeping with the diagnosis of APSS. The clinical presentation of APSS alone might be confusing and strongly resemble epidermolysis bullosa simplex making the differential diagnosis difficult.

The impact of temperature on mean local air age and thermal comfort in a stratum ventilated office

Energy Technology Data Exchange (ETDEWEB)

Tian, Lin; Lin, Zhang; Yao, Ting [Building Energy and Environmental Technology Research Unit, School of Energy and Environment and Division of Building Science and Technology, City University of Hong Kong, Hong Kong SAR (China); Liu, Jing; Wang, Qiuwang [State Key Lab of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an, 710049 (China)

2011-02-15

The influence of the supply air temperature on the mean local air age and thermal comfort of a typical individual office under stratum ventilation is investigated by a numerical method, which is validated by an experiment carried out by the authors. The results show that for an office, when the supply air temperature is increased from 19 C to 21 C, the corresponding mean occupied zone temperature rises from 24.5 C to 26.5 C. The inhaled air quality for the occupant is improved when supply air temperature rises from 19 C to 21 C. Also, the thermal comfort indices (predicted mean vote or PMV, predicted percentage of dissatisfied or PPD and predicted dissatisfied or PD) fulfill the requirements of ISO 7730 and CR 175 1998. For summer cooling operation, stratum ventilation may offer a feasible solution to elevated indoor temperatures, which are recommended by several governments in East Asia. (author)

Permeability of porour rhyolite

Science.gov (United States)

Cashman, K.; Rust, A.; Wright, H.; Roberge, J.

2003-04-01

The development of permeability in bubble-bearing magmas determines the efficiency of volatile escape during their ascent through volcanic conduits, which, in turn, controls their explosive potential. As permeability requires bubble connectivity, relationships between permeability and porosity in silicic magmas must be controlled by the formation, growth, deformation and coalescence of their constituent bubbles. Although permeability data on porous volcanic pyroclasts are limited, the database can be greatly extended by including data for ceramic and metallic foams1. Several studies indicate that a single number does not adequately describe the permeability of a foam because inertial effects, which predominate at high flow rates, cause deviations from Darcy's law. These studies suggest that permeability is best modeled using the Forschheimer equation to determine both the Darcy permeability (k1) and the non-Darcian (k2) permeability. Importantly, at the high porosities of ceramic foams (75-95%), both k1 and k2 are strongly dependent on pore size and geometry, suggesting that measurement of these parameters provides important information on foam structure. We determined both the connected porosity (by He-pycnometry) and the permeability (k1 and k2) of rhyolitic samples having a wide range in porosity (22-85%) and vesicle textures. In general, these data support previous observations of a power law relationship between connected porosity and Darcy permeability2. In detail, variations in k1 increase at higher porosities. Similarly, k2 generally increases in both mean and standard deviation with increasing porosity. Measurements made on three mutually perpendicular cores from individual pumice clasts suggest that some of the variability can be explained by anisotropy in the vesicle structure. By comparison with ceramic foams, we suggest that the remaining variability results from differences either in average vesicle size or, more likely, in the size of apertures

Intestinal permeability study of minoxidil: assessment of minoxidil as a high permeability reference drug for biopharmaceutics classification.

Science.gov (United States)

Ozawa, Makoto; Tsume, Yasuhiro; Zur, Moran; Dahan, Arik; Amidon, Gordon L

2015-01-05

The purpose of this study was to evaluate minoxidil as a high permeability reference drug for Biopharmaceutics Classification System (BCS). The permeability of minoxidil was determined in in situ intestinal perfusion studies in rodents and permeability studies across Caco-2 cell monolayers. The permeability of minoxidil was compared with that of metoprolol, an FDA reference drug for BCS classification. In rat perfusion studies, the permeability of minoxidil was somewhat higher than that of metoprolol in the jejunum, while minoxidil showed lower permeability than metoprolol in the ileum. The permeability of minoxidil was independent of intestinal segment, while the permeability of metoprolol was region-dependent. Similarly, in mouse perfusion study, the jejunal permeability of minoxidil was 2.5-fold higher than that of metoprolol. Minoxidil and metoprolol showed similar permeability in Caco-2 study at apical pH of 6.5 and basolateral pH of 7.4. The permeability of minoxidil was independent of pH, while metoprolol showed pH-dependent transport in Caco-2 study. Minoxidil exhibited similar permeability in the absorptive direction (AP-BL) in comparison with secretory direction (BL-AP), while metoprolol had higher efflux ratio (ER > 2) at apical pH of 6.5 and basolateral pH of 7.4. No concentration-dependent transport was observed for either minoxidil or metoprolol transport in Caco-2 study. Verapamil did not alter the transport of either compounds across Caco-2 cell monolayers. The permeability of minoxidil was independent of both pH and intestinal segment in intestinal perfusion studies and Caco-2 studies. Caco-2 studies also showed no involvement of carrier mediated transport in the absorption process of minoxidil. These results suggest that minoxidil may be an acceptable reference drug for BCS high permeability classification. However, minoxidil exhibited higher jejunal permeability than metoprolol and thus to use minoxidil as a reference drug would raise the

Calculating the dermal flux of chemicals with OELs based on their molecular structure: An attempt to assign the skin notation.

Science.gov (United States)

Kupczewska-Dobecka, Małgorzata; Jakubowski, Marek; Czerczak, Sławomir

2010-09-01

Our objectives included calculating the permeability coefficient and dermal penetration rates (flux value) for 112 chemicals with occupational exposure limits (OELs) according to the LFER (linear free-energy relationship) model developed using published methods. We also attempted to assign skin notations based on each chemical's molecular structure. There are many studies available where formulae for coefficients of permeability from saturated aqueous solutions (K(p)) have been related to physicochemical characteristics of chemicals. The LFER model is based on the solvation equation, which contains five main descriptors predicted from chemical structure: solute excess molar refractivity, dipolarity/polarisability, summation hydrogen bond acidity and basicity, and the McGowan characteristic volume. Descriptor values, available for about 5000 compounds in the Pharma Algorithms Database were used to calculate permeability coefficients. Dermal penetration rate was estimated as a ratio of permeability coefficient and concentration of chemical in saturated aqueous solution. Finally, estimated dermal penetration rates were used to assign the skin notation to chemicals. Defined critical fluxes defined from the literature were recommended as reference values for skin notation. The application of Abraham descriptors predicted from chemical structure and LFER analysis in calculation of permeability coefficients and flux values for chemicals with OELs was successful. Comparison of calculated K(p) values with data obtained earlier from other models showed that LFER predictions were comparable to those obtained by some previously published models, but the differences were much more significant for others. It seems reasonable to conclude that skin should not be characterised as a simple lipophilic barrier alone. Both lipophilic and polar pathways of permeation exist across the stratum corneum. It is feasible to predict skin notation on the basis of the LFER and other published

Sub-core permeability and relative permeability characterization with Positron Emission Tomography

Science.gov (United States)

Zahasky, C.; Benson, S. M.

2017-12-01

This study utilizes preclinical micro-Positron Emission Tomography (PET) to image and quantify the transport behavior of pulses of a conservative aqueous radiotracer injected during single and multiphase flow experiments in a Berea sandstone core with axial parallel bedding heterogeneity. The core is discretized into streamtubes, and using the micro-PET data, expressions are derived from spatial moment analysis for calculating sub-core scale tracer flux and pore water velocity. Using the flux and velocity data, it is then possible to calculate porosity and saturation from volumetric flux balance, and calculate permeability and water relative permeability from Darcy's law. Full 3D simulations are then constructed based on this core characterization. Simulation results are compared with experimental results in order to test the assumptions of the simple streamtube model. Errors and limitations of this analysis will be discussed. These new methods of imaging and sub-core permeability and relative permeability measurements enable experimental quantification of transport behavior across scales.

Permeability prediction in chalks

DEFF Research Database (Denmark)

Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Prasad, Manika

2011-01-01

The velocity of elastic waves is the primary datum available for acquiring information about subsurface characteristics such as lithology and porosity. Cheap and quick (spatial coverage, ease of measurement) information of permeability can be achieved, if sonic velocity is used for permeability p...... significantly using the effective specific surface as the fluid-flow concept. The FZI unit is appropriate for highly permeable sedimentary rocks such as sandstones and limestones that have small surface areas....

Comparative field permeability measurement of permeable pavements using ASTM C1701 and NCAT permeameter methods.

Science.gov (United States)

Li, Hui; Kayhanian, Masoud; Harvey, John T

2013-03-30

Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterization of oily mature skin by biophysical and skin imaging techniques.

Science.gov (United States)

de Melo, M O; Maia Campos, P M B G

2018-02-13

The skin is a complex biological system and may suffer change according to the environmental factors, as higher temperatures can increase sebum excretion, presenting oiliness and acne. These alterations can persist during the aging and provoke more changes in aged skin. In this study we evaluated the mature oily skin characteristics using biophysical and skin imaging techniques. Sixty healthy female subjects, aged between 39 and 55 years old were recruited and separated into 2 groups according to their skin type: normal/dry and oily skin. The skin was evaluated in terms of stratum corneum water content, transepidermal water loss (TEWL) sebum content, dermis thickness and echogenicity, skin microrelief, and pores content. The mature oily skin presented no significant differences when compared to the normal/dry skin on the stratum corneum water content and TEWL parameters. The sebum content was significantly higher on the oily skin group. The microrelief analysis showed an increase of skin roughness values in the oily skin and increase of scaliness in the normal/dry skin. The oily skin showed lower dermis echogenicity mainly in the frontal region and higher dermis thickness when compared to normal/dry skin. The mature oily skin showed different characteristics from normal/dry skin in terms of sebum content, microrelief parameters, and dermis thickness. This way, the characterization of mature oily skin in an objective way is very important to development of dermocosmetic products for more effective treatments focused specially on this type of skin. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Putative photoacoustic damage in skin induced by pulsed ArF excimer laser

Energy Technology Data Exchange (ETDEWEB)

Watanabe, S.; Flotte, T.J.; McAuliffe, D.J.; Jacques, S.L.

1988-05-01

Argon-fluoride excimer laser ablation of guinea pig stratum corneum causes deeper tissue damage than expected for thermal or photochemical mechanisms, suggesting that photoacoustic waves have a role in tissue damage. Laser irradiation (193 nm, 14-ns pulse) at two different radiant exposures, 62 and 156 mJ/cm2 per pulse, was used to ablate the 15-microns-thick stratum corneum of the skin. Light and electron microscopy of immediate biopsies demonstrated damage to fibroblasts as deep as 88 and 220 microns, respectively, below the ablation site. These depths are far in excess of the optical penetration depth of 193-nm light (1/e depth = 1.5 micron). The damage is unlikely to be due to a photochemical mechanism because (a) the photons will not penetrate to these depths, (b) it is a long distance for toxic photoproducts to diffuse, and (c) damage is proportional to laser pulse intensity and not the total dose that accumulates in the residual tissue; therefore, reciprocity does not hold. Damage due to a thermal mechanism is not expected because there is not sufficient energy deposited in the tissue to cause significant heating at such depths. The damage is most likely due to a photoacoustic mechanism because (a) photoacoustic waves can propagate deep into tissue, (b) the depth of damage increases with increasing laser pulse intensity rather than with increasing total residual energy, and (c) the effects are immediate. These effects should be considered in the evaluation of short pulse, high peak power laser-tissue interactions.

Hydrogel-forming microneedle arrays exhibit antimicrobial properties: potential for enhanced patient safety.

Science.gov (United States)

Donnelly, Ryan F; Singh, Thakur Raghu Raj; Alkilani, Ahlam Zaid; McCrudden, Maelíosa T C; O'Neill, Shannon; O'Mahony, Conor; Armstrong, Keith; McLoone, Nabla; Kole, Prashant; Woolfson, A David

2013-07-15

We describe, for the first time, the microbial characterisation of hydrogel-forming polymeric microneedle arrays and the potential for passage of microorganisms into skin following microneedle penetration. Uniquely, we also present insights into the storage stability of these hydroscopic formulations, from physical and microbiological viewpoints, and examine clinical performance and safety in human volunteers. Experiments employing excised porcine skin and radiolabelled microorganisms showed that microorganisms can penetrate skin beyond the stratum corneum following microneedle puncture. Indeed, the numbers of microorganisms crossing the stratum corneum following microneedle puncture were greater than 10⁵ cfu in each case. However, no microorganisms crossed the epidermal skin. When using a 21G hypodermic needle, more than 10⁴ microorganisms penetrated into the viable tissue and 10⁶ cfu of Candida albicans and Staphylococcus epidermidis completely crossed the epidermal skin in 24 h. The hydrogel-forming materials contained no microorganisms following de-moulding and exhibited no microbial growth during storage, while also maintaining their mechanical strength, apart from when stored at relative humidities of 86%. No microbial penetration through the swelling microneedles was detectable, while human volunteer studies confirmed that skin or systemic infection is highly unlikely when polymeric microneedles are used for transdermal drug delivery. Since no pharmacopoeial standards currently exist for microneedle-based products, the exact requirements for a proprietary product based on hydrogel-forming microneedles are at present unclear. However, we are currently working towards a comprehensive specification set for this microneedle system that may inform future developments in this regard. Copyright © 2013 Elsevier B.V. All rights reserved.

Measuring the effects of topically applied skin optical clearing agents and modeling the effects and consequences for laser therapies

Science.gov (United States)

Verkruysse, Wim; Khan, Misbah; Choi, Bernard; Svaasand, Lars O.; Nelson, J. Stuart

2005-04-01

Human skin prepared with an optical clearing agent manifests reduced scattering as a result of de-hydration and refractive index matching. This has potentially large effects for laser therapies of several skin lesions such as port wine stain, hair removal and tattoo removal. With most topically applied clearing agents the clearing effect is limited because they penetrate poorly through the intact superficial skin layer (stratum corneum). Agent application modi other than topical are impractical and have limited the success of optical clearing in laser dermatology. In recent reports, however, a mixture of lipofylic and hydrofylic agents was shown to successfully penetrate through the intact stratum corneum layer which has raised new interest in this field. Immediately after application, the optical clearing effect is superficial and, as the agent diffuses through the skin, reduced scattering is manifested in deeper skin layers. For practical purposes as well as to maximize therapeutic success, it is important to quantify the reduced scattering as well as the trans-cutaneous transport dynamics of the agent. We determined the time and tissue depth resolved effects of optically cleared skin by inserting a microscopic reflector array in the skin. Depth dependent light intensity was measured by quantifying the signal of the reflector array with optical coherence tomography. A 1-dimensional mass diffusion model was used to estimate a trans-cutaneous transport diffusion constant for the clearing agent mixture. The results are used in Monte Carlo modeling to determine the optimal time of laser treatment after topical application of the optical clearing agent.

Gravimetric analysis and differential scanning calorimetric studies on glycerin-induced skin hydration.

Science.gov (United States)

Lee, Ae-Ri Cho; Moon, Hee Kyung

2007-11-01

A thermal gravimetric analysis (TGA) and a differential scanning calorimetry (DSC) were carried out to characterize the water property and an alteration of lipid phase transition of stratum corneum (SC) by glycerin. In addition, the relationship between steady state skin permeation rate and skin hydration in various concentrations of glycerin was investigated. Water vapor absorption-desorption was studied in the hairless mouse stratum corneum. Dry SC samples were exposed to different conc. of glycerin (0-50%) followed by exposure to dry air and the change in weight property was monitored over time by use of TGA. In DSC study, significant decrease in DeltaH of the lipid transition in 10% glycerin and water treated sample: the heat of lipid transition of normal, water, 10% glycerin treated SC were 6.058, 4.412 and 4.316 mJ/mg, respectively. In 10% glycerin treated SCs, the Tc of water shifts around 129 degrees C, corresponding to the weakly bound secondary water. In 40% glycerin treated SC, the Tc of water shifts to 144 degrees C corresponding to strongly bound primary water. There was a good correlation between the hydration property of the skin and the steady state skin flux with the correlation coefficient (r2=0.94). As the hydration increased, the steady state flux increased. As glycerin concentration increased, hydration property decreased. High diffusivity induced by the hydration effect of glycerin and water could be the major contributing factor for the enhanced skin permeation of nicotinic acid (NA).

Does dietary fluid intake affect skin hydration in healthy humans? A systematic literature review.

Science.gov (United States)

Akdeniz, M; Tomova-Simitchieva, T; Dobos, G; Blume-Peytavi, U; Kottner, J

2018-02-02

Associations between daily amounts of drinking water and skin hydration and skin physiology receive increasingly attention in the daily life and in clinical practice. However, there is a lack of evidence of dermatological benefits from drinking increased amounts of water. Pubmed and Web of Science were searched without any restrictions of publication dates. References of included papers and related reviews were checked. Eligibility criteria were primary intervention and observational studies investigating the effects of fluid intake on skin properties in English, German, Spanish or Portuguese language, including subjects being healthy and 18+ years. Searches resulted in 216 records, 23 articles were read in full text, and six were included. The mean age of the samples ranged from 24 to 56 years. Overall the evidence is weak in terms of quantity and methodological quality. Disregarding the methodological limitations a slight increase in stratum corneum and "deep" skin hydration was observed after additional water intake, particularly in individuals with lower prior water consumption. Reductions of clinical signs of dryness and roughness were observed. The extensibility and elasticity of the skin increased slightly. Unclear associations were shown between water intake and transepidermal water loss, sebum content, and skin surface pH. Additional dietary water intake may increase stratum corneum hydration. The underlying biological mechanism for this possible relationship is unknown. Whether this association also exists in aged subjects is unclear. Research is needed to answer the question whether increased fluid intake decreases signs of dry skin. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Relative Permeability of Fractured Rock

Energy Technology Data Exchange (ETDEWEB)

Mark D. Habana

2002-06-30

Contemporary understanding of multiphase flow through fractures is limited. Different studies using synthetic fractures and various fluids have yielded different relative permeability-saturation relations. This study aimed to extend the understanding of multiphase flow by conducting nitrogen-water relative permeability experiments on a naturally-fractured rock from The Geysers geothermal field. The steady-state approach was used. However, steady state was achieved only at the endpoint saturations. Several difficulties were encountered that are attributed to phase interference and changes in fracture aperture and surface roughness, along with fracture propagation/initiation. Absolute permeabilities were determined using nitrogen and water. The permeability values obtained change with the number of load cycles. Determining the absolute permeability of a core is especially important in a fractured rock. The rock may change as asperities are destroyed and fractures propagate or st rain harden as the net stresses vary. Pressure spikes occurred in water a solute permeability experiments. Conceptual models of an elastic fracture network can explain the pressure spike behavior. At the endpoint saturations the water relative permeabilities obtained are much less than the nitrogen gas relative permeabilities. Saturations were determined by weighing and by resistivity calculations. The resistivity-saturation relationship developed for the core gave saturation values that differ by 5% from the value determined by weighing. Further work is required to complete the relative permeability curve. The steady-state experimental approach encountered difficulties due to phase interference and fracture change. Steady state may not be reached until an impractical length of time. Thus, unsteady-state methods should be pursued. In unsteady-state experiments the challenge will be in quantifying rock fracture change in addition to fluid flow changes.

Experimental investigation into the interaction between the human body and room airflow and its effect on thermal comfort under stratum ventilation.

Science.gov (United States)

Cheng, Y; Lin, Z

2016-04-01

Room occupants' comfort and health are affected by the airflow. Nevertheless, they themselves also play an important role in indoor air distribution. This study investigated the interaction between the human body and room airflow under stratum ventilation. Simplified thermal manikin was employed to effectively resemble the human body as a flow obstacle and/or free convective heat source. Unheated and heated manikins were designed to fully evaluate the impact of the manikin at various airflow rates. Additionally, subjective human tests were conducted to evaluate thermal comfort for the occupants in two rows. The findings show that the manikin formed a local blockage effect, but the supply airflow could flow over it. With the body heat from the manikin, the air jet penetrated farther compared with that for the unheated manikin. The temperature downstream of the manikin was also higher because of the convective effect. Elevating the supply airflow rate from 7 to 15 air changes per hour varied the downstream airflow pattern dramatically, from an uprising flow induced by body heat to a jet-dominated flow. Subjective assessments indicated that stratum ventilation provided thermal comfort for the occupants in both rows. Therefore, stratum ventilation could be applied in rooms with occupants in multiple rows. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Electrokinetic effects and fluid permeability

International Nuclear Information System (INIS)

Berryman, J.G.

2003-01-01

Fluid permeability of porous media depends mainly on connectivity of the pore space and two physical parameters: porosity and a pertinent length-scale parameter. Electrical imaging methods typically establish connectivity and directly measure electrical conductivity, which can then often be related to porosity by Archie's law. When electrical phase measurements are made in addition to the amplitude measurements, information about the pertinent length scale can then be obtained. Since fluid permeability controls the ability to flush unwanted fluid contaminants from the subsurface, inexpensive maps of permeability could improve planning strategies for remediation efforts. Detailed knowledge of fluid permeability is also important for oil field exploitation, where knowledge of permeability distribution in three dimensions is a common requirement for petroleum reservoir simulation and analysis, as well as for estimates on the economics of recovery

[How safe are nanoparticles?].

Science.gov (United States)

Lademann, J; Meinke, M; Sterry, W; Patzelt, A

2009-04-01

Nanoparticles are experiencing an increasing application in dermatology and cosmetics. In both application areas, the requirements of nanoparticles are in most cases widely different. As a component of sunscreens, the nanoparticles are supposed to remain on the skin surface or in the upper most layers of the stratum corneum to protect the skin against UV-radiation of the sun. Whereas, on the other hand, when particulate substances are used as carrier systems for drugs, they have to cross the skin barrier to reach the target sites within the living tissue. We discuss the perspectives and risks of the topical application of nanoparticles.

Skin optical clearing for improvement of laser tattoo removal

Science.gov (United States)

Bashkatov, A. N.; Genina, E. A.; Tuchin, V. V.; Altshuler, G. B.

2009-06-01

The possibility of improvement of laser tattoo removal due to the optical clearing of human skin is investigated. It is shown experimentally that previously perforation of skin stratum corneum allows increasing tattoo image contrast at topical administration of immersion agent in contrast with non-perforated skin. Computer Monte Carlo simulation shows that at the optical clearing of upper skin layers the tattoo image contrast and the photon fraction absorbed in the tattoo area at the depths of 0.5 or 1.0 mm increase, that allows significant decreasing of the power of laser radiation used at laser thermolysis.

Anatomy of the Skin and the Pathogenesis of Nonmelanoma Skin Cancer.

Science.gov (United States)

Losquadro, William D

2017-08-01

Skin is composed of the epidermis, dermis, and adnexal structures. The epidermis is composed of 4 layers-the stratums basale, spinosum, granulosum, and corneum. The dermis is divided into a superficial papillary dermis and deeper reticular dermis. Collagen and elastin within the reticular dermis are responsible for skin tensile strength and elasticity, respectively. The 2 most common kinds of nonmelanoma skin cancers are basal cell and squamous cell carcinoma. Both are caused by a host of environmental and genetic factors, although UV light exposure is the single greatest predisposing factor. Copyright © 2017 Elsevier Inc. All rights reserved.

Tinea versicolor, tinea nigra, white piedra, and black piedra.

Science.gov (United States)

Bonifaz, Alexandro; Gómez-Daza, Fernando; Paredes, Vanessa; Ponce, Rosa María

2010-03-04

Superficial mycoses are fungal infections limited to the stratum corneum and its adnexal structures. The most frequent types are dermatophytoses or tineas. Tinea versicolor involves the skin in the form of hypochromic or hyperchromic plaques, and tinea nigra affects the skin of the palms with dark plaques. White piedra and black piedra are parasitic infections of scalp hairs in the form of concretions caused by fungal growth. Diagnosis of these mycoses is made from mycologic studies, direct examination, stains, and isolation, and identification of the fungi. Treatment includes systemic antifungals, topical antifungals, and keratolytics. Copyright 2010 Elsevier Inc. All rights reserved.

Analysis of skin tissues spatial fluorescence distribution by the Monte Carlo simulation

International Nuclear Information System (INIS)

Churmakov, D Y; Meglinski, I V; Piletsky, S A; Greenhalgh, D A

2003-01-01

A novel Monte Carlo technique of simulation of spatial fluorescence distribution within the human skin is presented. The computational model of skin takes into account the spatial distribution of fluorophores, which would arise due to the structure of collagen fibres, compared to the epidermis and stratum corneum where the distribution of fluorophores is assumed to be homogeneous. The results of simulation suggest that distribution of auto-fluorescence is significantly suppressed in the near-infrared spectral region, whereas the spatial distribution of fluorescence sources within a sensor layer embedded in the epidermis is localized at an 'effective' depth

Analysis of skin tissues spatial fluorescence distribution by the Monte Carlo simulation

Energy Technology Data Exchange (ETDEWEB)

Churmakov, D Y [School of Engineering, Cranfield University, Cranfield, MK43 0AL (United Kingdom); Meglinski, I V [School of Engineering, Cranfield University, Cranfield, MK43 0AL (United Kingdom); Piletsky, S A [Institute of BioScience and Technology, Cranfield University, Silsoe, MK45 4DT (United Kingdom); Greenhalgh, D A [School of Engineering, Cranfield University, Cranfield, MK43 0AL (United Kingdom)

2003-07-21

A novel Monte Carlo technique of simulation of spatial fluorescence distribution within the human skin is presented. The computational model of skin takes into account the spatial distribution of fluorophores, which would arise due to the structure of collagen fibres, compared to the epidermis and stratum corneum where the distribution of fluorophores is assumed to be homogeneous. The results of simulation suggest that distribution of auto-fluorescence is significantly suppressed in the near-infrared spectral region, whereas the spatial distribution of fluorescence sources within a sensor layer embedded in the epidermis is localized at an 'effective' depth.

Analysis of skin tissues spatial fluorescence distribution by the Monte Carlo simulation

Science.gov (United States)

Y Churmakov, D.; Meglinski, I. V.; Piletsky, S. A.; Greenhalgh, D. A.

2003-07-01

A novel Monte Carlo technique of simulation of spatial fluorescence distribution within the human skin is presented. The computational model of skin takes into account the spatial distribution of fluorophores, which would arise due to the structure of collagen fibres, compared to the epidermis and stratum corneum where the distribution of fluorophores is assumed to be homogeneous. The results of simulation suggest that distribution of auto-fluorescence is significantly suppressed in the near-infrared spectral region, whereas the spatial distribution of fluorescence sources within a sensor layer embedded in the epidermis is localized at an `effective' depth.

Notalgia Paraesthetica

Directory of Open Access Journals (Sweden)

Malakar Subrata

1998-01-01

Full Text Available Two cases of notalgia paraesthetica (NP are presented. Both the patients were female and above 30 years of age. Clinically the lesions closely simulated macular amyloidosis over interscapular region. However, history of associated pruritus, tingling, fornication and altered sensation over the patch pointed towards the diagnosis of NP, Histopathological examinations in both the cases revealed intraepidermal necrotic keratinocytes with desquamation remnants of necrotic keratinocytes in the stratum corneum. Congo red and crystal violet stains were negative for presence of amyloidal in thedermis. In both the patients, symptomatic improvement was observed after 3 weeks’ application of topical capsaicin.

Acral peeling skin syndrome: report of two cases.

Science.gov (United States)

García, Elena García; Carreño, Rosario Granados; Martínez González, Miguel A; Reyes, José Jiménez

2005-01-01

Peeling skin syndrome is a rare dermatosis characterized by spontaneous and painless peeling of the skin. The authors report two patients with history of spontaneous, asymptomatic, and noninflammatory peeling skin of the acral surfaces after soaking in water. On light microscopy, blisters were located in the mid layers of the stratum corneum, above the granular layer. Ultrastructural examination revealed increased intercellular lipids and abnormal, "moth-eaten," keratohyalin granules, but the authors were unable to determine whether the separation initiated within the horny cells or between adjacent cells. These patients represented a localized variant of peeling skin syndrome.

Lipids and skin barrier function - a clinical perspective

DEFF Research Database (Denmark)

Jungersted, J.M.; Hellgren, Lars; Jemec, G.B.E.

2008-01-01

The stratum corneum (SC) protects us from dehydration and external dangers. Much is known about the morphology of the SC and penetration of drugs through it, but the data are mainly derived from in vitro and animal experiments. In contrast, only a few studies have the human SC lipids as their focus...... and in particular, the role of barrier function in the pathogenesis of skin disease and its subsequent treatment protocols. The 3 major lipids in the SC of importance are ceramides, free fatty acids, and cholesterol. Human studies comparing levels of the major SC lipids in patients with atopic dermatitis...

应用荧光图像对丹磺酰氯染色后角质层转化时间的评价%The Evaluation of Stratum Corneum Turnover Time After Dansyl Chloride Staining by Fluorescence Image

Institute of Scientific and Technical Information of China (English)

刘娜; 王学民; 程英; 武苏捷; 史红玉; 朱翔

2012-01-01

Objective To evaluate stratum eorneum turnover time after the dansyl chloride staining by fluorescence images and its grey values. Methods Thirty subjects were stained by dansyl chloride at inner forearm. The dyeing was evaluated by visual scoring under Wood's lamp once a day in consistant 28 days. At the same time ultraviolet fluorescence images were taken by a fluorescence camera twice a week. Then we got the visual score of images base on the staining intensity of these pictures. The grey value of the fluorescence images were analyzed by Photoshop software. Results During 28 days, the dyeing at the study site disappeared gradually. And the grey value of fluorescence images decreased gradually as well. There were good correlation among the grey value of fluorescence image and the score of visual assessment under Wood's lamp and the scores of image assessment. Conclusion The fluorescence images and its grey value could be the objective evaluation method for the stratum eorneum turnover time by dansyl chloride staining. The sensitivity of evaluation could be improved and the fluorescence result could be got.%目的 丹磺酰氯皮肤染色后,应用荧光图像及其灰度值对角质层的转化时间进行评价.方法 30名受试者的前臂内侧应用丹磺酰氯染色,染色后每天在伍德氏灯下肉眼评价染色强度,连续28d.同时每周应用相机摄取荧光图像2次,根据这些图像的染色强度得到荧光图像的肉眼评分.应用Photoshop软件分析摄取图像得到荧光图像的灰度值.结果 经过28d的试验,皮肤染色逐渐脱落,而荧光图像的灰度值也随时间逐渐减小.荧光图像灰度值与伍德氏灯下肉眼评分、图像的肉眼评分具有较好的一致性.结论 应用荧光图像评分及其灰度值可以客观地评价丹磺酰氯皮肤染色的脱落情况,提高试验评分的敏感性,并可获取数字化的结果.

Compact rock material gas permeability properties

Energy Technology Data Exchange (ETDEWEB)

Wang, Huanling, E-mail: whl_hm@163.com [Key Laboratory of Coastal Disaster and Defence, Ministry of Education, Hohai University, Nanjing 210098 (China); LML, University of Lille, Cite Scientifique, 59655 Villeneuve d’Ascq (France); Xu, Weiya; Zuo, Jing [Institutes of Geotechnical Engineering, Hohai University, Nanjing 210098 (China)

2014-09-15

Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO{sub 2,} shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10{sup −19} m{sup 2}; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10{sup −17} m{sup 2}; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens’ permeability evolution is related to the relative particle movements and microcrack closure.

Permeability During Magma Expansion and Compaction

Science.gov (United States)

Gonnermann, Helge. M.; Giachetti, Thomas; Fliedner, Céline; Nguyen, Chinh T.; Houghton, Bruce F.; Crozier, Joshua A.; Carey, Rebecca J.

2017-12-01

Plinian lapilli from the 1060 Common Era Glass Mountain rhyolitic eruption of Medicine Lake Volcano, California, were collected and analyzed for vesicularity and permeability. A subset of the samples were deformed at a temperature of 975°, under shear and normal stress, and postdeformation porosities and permeabilities were measured. Almost all undeformed samples fall within a narrow range of vesicularity (0.7-0.9), encompassing permeabilities between approximately 10-15 m2 and 10-10 m2. A percolation threshold of approximately 0.7 is required to fit the data by a power law, whereas a percolation threshold of approximately 0.5 is estimated by fitting connected and total vesicularity using percolation modeling. The Glass Mountain samples completely overlap with a range of explosively erupted silicic samples, and it remains unclear whether the erupting magmas became permeable at porosities of approximately 0.7 or at lower values. Sample deformation resulted in compaction and vesicle connectivity either increased or decreased. At small strains permeability of some samples increased, but at higher strains permeability decreased. Samples remain permeable down to vesicularities of less than 0.2, consistent with a potential hysteresis in permeability-porosity between expansion (vesiculation) and compaction (outgassing). We attribute this to retention of vesicle interconnectivity, albeit at reduced vesicle size, as well as bubble coalescence during shear deformation. We provide an equation that approximates the change in permeability during compaction. Based on a comparison with data from effusively erupted silicic samples, we propose that this equation can be used to model the change in permeability during compaction of effusively erupting magmas.

Determination of Abutment Pressure in Coal Mines with Extremely Thick Alluvium Stratum: A Typical Kind of Rockburst Mines in China

Science.gov (United States)

Zhu, Sitao; Feng, Yu; Jiang, Fuxing

2016-05-01

This paper investigates the abutment pressure distribution in coal mines with extremely thick alluvium stratum (ETAS), which is a typical kind of mines encountering frequent intense rockbursts in China. This occurs due to poor understanding to abutment pressure distribution pattern and the consequent inappropriate mine design. In this study, a theoretical computational model of abutment pressure for ETAS longwall panels is proposed based on the analysis of load transfer mechanisms of key stratum (KS) and ETAS. The model was applied to determine the abutment pressure distribution of LW2302S in Xinjulong Coal Mine; the results of stress and microseismic monitoring verified the rationality of this model. The calculated abutment pressure of LW2302S was also used in the terminal mining line design of LW2301N for rockburst prevention, successfully protecting the main roadway from the adverse influence of the abutment pressure.

Film Permeability Determination Using Static Permeability Cells

Science.gov (United States)

The permeability of tarps to soil fumigant pesticides varies depending on the active ingredient chemical: dimethyl disulfide (DMDS), methyl bromide, chloropicrin, or other. The diffusion rate can be represented by the mass transfer coefficient (MTC).

Permeability testing of biomaterial membranes

Energy Technology Data Exchange (ETDEWEB)

Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B [NMI Natural and Medical Sciences Institute at University Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen (Germany); Ahlers, M [GELITA AG, Gammelsbacher Str. 2, D-69412 Eberbach (Germany)], E-mail: schlosshauer@nmi.de

2008-09-01

The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation.

Permeability testing of biomaterial membranes

International Nuclear Information System (INIS)

Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B; Ahlers, M

2008-01-01

The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation

Permeability-Porosity Relationships of Subduction Zone Sediments

Science.gov (United States)

Gamage, K.; Screaton, E.; Bekins, B.; Aiello, I.

2008-12-01

Permeability-porosity relationships for sediments from Northern Barbados, Costa Rica, Nankai, and Peru subduction zones were examined based on their sediment type and grain size distribution. Greater correlation was observed between permeability and porosity for siliciclastic sediments, diatom oozes, and nannofossil chalk than for nannofossil oozes. For siliciclastic sediments, grouping of sediments by clay content yields relationships that are generally consistent with results from other marine settings and suggest decreasing permeability for a given porosity as clay content increases. Correction of measured porosities for smectite content generally improves the quality of permeability-porosity relationships. The relationship between permeability and porosity for diatom oozes may be controlled by the amount of clay present in the ooze, causing diatom oozes to behave similarly to siliciclastic sediments. For a given porosity the nannofossil oozes have higher permeability values by 1.5 orders of magnitude than the siliciclastic sediments. However, the use of a permeability-porosity relation may not be appropriate for unconsolidated carbonates such as nannofossil oozes. This study provided insight to the effects of porosity correction for smectite, variations in lithology and grain size in permeability-porosity relationships. However, further progress in delineating controls on permeability will require more careful and better documented permeability tests on characterized samples.

Gas and Water Permeability of Concrete

Energy Technology Data Exchange (ETDEWEB)

Villar, M. V.; Martin, P. L.; Romero, F. J.; Gutierrez-Rodirgo, V.; Barcala, J. M.

2012-11-01

The gas pressure of concrete samples was measured in an unsteady-state equipment working under low injection pressures and in a newly fine tuned steady-state setup working under different pressures. These measurements allowed the estimation of the intrinsic and relative gas permeability of the concrete and of the effect of boundary conditions on them. Permeability decreased with water content, but it was also greatly affected by the hydraulic history of concrete, i.e. if it had been previously dried or wetted. In particular, and for a given degree of saturation, the gas permeability of concrete previously saturated was lower than if the concrete had been just air dried or saturated after air drying. In any case, the gas permeability was about two orders of magnitude higher than the liquid water permeability (10-16 vs. 10-18 m2), probably due to the chemical reactions taking place during saturation (carbonation). The relative gas permeability of concrete increased sharply for water degrees of saturation smaller than 50%. The boundary conditions also affected the gas permeability, which seemed to be mostly conditioned by the back pressure and the confining pressure, increasing as the former increased and decreasing as the latter increased, i.e. decreasing as the effective pressure increased. Overall the increase of pressure head or injection pressure implied a decrease in gas permeability. External,microcracking during air-drying could not be ruled out as responsible for the decrease of permeability with confining pressure. The apparent permeability obtained applying the Klinkenberg method for a given effective pressure was only slightly smaller than the average of all the values measured for the same confining pressure range. For this reason it is considered that the Klinkenberg effect was not relevant in the range of pressures applied. (Author) 37 refs.

Permeability of cork to gases.

Science.gov (United States)

Faria, David P; Fonseca, Ana L; Pereira, Helen; Teodoro, Orlando M N D

2011-04-27

The permeability of gases through uncompressed cork was investigated. More than 100 samples were assessed from different plank qualities to provide a picture of the permeability distribution. A novel technique based on a mass spectrometer leak detector was used to directly measure the helium flow through the central area of small disks 10 mm in diameter and 2 mm thick. The permeability for nitrogen, oxygen, and other gases was measured by the pressure rise technique. Boiled and nonboiled cork samples from different sections were evaluated. An asymmetric frequency distribution ranging 3 orders of magnitude (roughly from 1 to 1000 μmol/(cm·atm·day)) for selected samples without macroscopic defects was found, having a peak below 100 μmol/(cm·atm·day). Correlation was found between density and permeability: higher density samples tend to show lower permeability. However, boiled cork showed a mean lower permeability despite having a lower density. The transport mechanism of gases through cork was also examined. Calculations suggest that gases permeate uncompressed cork mainly through small channels between cells under a molecular flow regime. The diameter of such channels was estimated to be in the range of 100 nm, in agreement with the plasmodesmata size in the cork cell walls.

Clogging in permeable concrete: A review.

Science.gov (United States)

Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R

2017-05-15

Permeable concrete (or "pervious concrete" in North America) is used to reduce local flooding in urban areas and is an important sustainable urban drainage system. However, permeable concrete exhibits reduction in permeability due to clogging by particulates, which severely limits service life. This paper reviews the clogging mechanism and current mitigating strategies in order to inform future research needs. The pore structure of permeable concrete and characteristics of flowing particulates influence clogging, which occurs when particles build-up and block connected porosity. Permeable concrete requires regular maintenance by vacuum sweeping and pressure washing, but the effectiveness and viability of these methods is questionable. The potential for clogging is related to the tortuosity of the connected porosity, with greater tortuosity resulting in increased potential for clogging. Research is required to develop permeable concrete that can be poured on-site, which produces a pore structure with significantly reduced tortuosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Geothermal Permeability Enhancement - Final Report

Energy Technology Data Exchange (ETDEWEB)

Joe Beall; Mark Walters

2009-06-30

The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

Seismic response of bridge pier on rigid caisson foundation in soil stratum

Science.gov (United States)

Tsigginos, C.; Gerolymos, N.; Assimaki, D.; Gazetas, G.

2008-03-01

An analytical method to study the seismic response of a bridge pier supported on a rigid caisson foundation embedded in a deep soil stratum underlain by a homogeneous half space is developed. The method reproduces the kinematic and inertial responses, using translational and rotational distributed Winkler springs and dashpots to simulate the soil-caisson interaction. Closed-form solutions are given in the frequency domain for vertical harmonic S-wave excitation. Comparison with results from finite element (FE) analysis and other available solutions demonstrates the reliability of the model. Results from parametric studies are given for the kinematic and inertial responses. The modification of the fundamental period and damping ratio of the bridge due to soil-structure interaction is graphically illustrated.

A Reconciliation of Packed Column Permeability Data: Column Permeability as a Function of Particle Porosity

Directory of Open Access Journals (Sweden)

Hubert M. Quinn

2014-01-01

Full Text Available In his textbook teaching of packed bed permeability, Georges Guiochon uses mobile phase velocity as the fluid velocity term in his elaboration of the Darcy permeability equation. Although this velocity frame makes a lot of sense from a thermodynamic point of view, it is valid only with respect to permeability at a single theoretical boundary condition. In his more recent writings, however, Guiochon has departed from his long-standing mode of discussing permeability in terms of the Darcy equation and has embraced the well-known Kozeny-Blake equation. In this paper, his teaching pertaining to the constant in the Kozeny-Blake equation is examined and, as a result, a new correlation coefficient is identified and defined herein based on the velocity frame used in his teaching. This coefficient correlates pressure drop and fluid velocity as a function of particle porosity. We show that in their experimental protocols, Guiochon et al. have not adhered to a strict material balance of permeability which creates a mismatch of particle porosity and leads to erroneous conclusions regarding the value of the permeability coefficient in the Kozeny-Blake equation. By correcting the experimental data to properly reflect particle porosity we reconcile the experimental results of Guiochon and Giddings, resulting in a permeability reference chart which is presented here for the first time. This reference chart demonstrates that Guiochon’s experimental data, when properly normalized for particle porosity and other related discrepancies, corroborates the value of 267 for the constant in the Kozeny-Blake equation which was derived by Giddings in 1965.

Crustal permeability: Introduction to the special issue

Science.gov (United States)

Ingebritsen, Steven E.; Gleeson, Tom

2015-01-01

The topic of crustal permeability is of broad interest in light of the controlling effect of permeability on diverse geologic processes and also timely in light of the practical challenges associated with emerging technologies such as hydraulic fracturing for oil and gas production (‘fracking’), enhanced geothermal systems, and geologic carbon sequestration. This special issue of Geofluids is also motivated by the historical dichotomy between the hydrogeologic concept of permeability as a static material property that exerts control on fluid flow and the perspective of economic geologists, geophysicists, and crustal petrologists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. Issues associated with fracking, enhanced geothermal systems, and geologic carbon sequestration have already begun to promote a constructive dialog between the static and dynamic views of permeability, and here we have made a conscious effort to include both viewpoints. This special issue also focuses on the quantification of permeability, encompassing both direct measurement of permeability in the uppermost crust and inferential permeability estimates, mainly for the deeper crust.

Multi-Stratum Networks: toward a unified model of on-line identities

DEFF Research Database (Denmark)

Rossi, Luca; Magnani, Matteo

2012-01-01

One of the reasons behind the success of Social Network Analysis is its simple and general graph model made of nodes (representing individuals) and ties. However, when we focus on our daily on-line experience we must confront a more complex scenario: people inhabitate several on-line spaces...... interacting to several communities active on various technological infrastructures like Twitter, Facebook, YouTube or FourSquare and with distinct social objectives. This constitutes a complex network of interconnected networks where users' identities are spread and where information propagates navigating...... through different communities and social platforms. In this article we introduce a model for this layered scenario that we call multi-stratum network. Through a theoretical discussion and the analysis of real-world data we show how not only focusing on a single network may provide a very partial...

The application of anethole, menthone, and eugenol in transdermal penetration of valsartan: Enhancement and mechanistic investigation.

Science.gov (United States)

Ahad, Abdul; Aqil, Mohd; Ali, Asgar

2016-01-01

The main barrier for transdermal delivery is the obstacle property of the stratum corneum. Many types of chemical penetration enhancers have been used to breach the skin barrier; among the penetration enhancers, terpenes are found as the most highly advanced, safe, and proven category. In the present investigation, the terpenes anethole, menthone, and eugenol were used to enhance the permeation of valsartan through rat skin in vitro and their enhancement mechanism was investigated. Skin permeation studies of valsartan across rat skin in the absence and the presence of terpenes at 1% w/v, 3% w/v, and 5% w/v in vehicle were carried out using the transdermal diffusion cell sampling system across rat skin and samples were withdrawn from the receptor compartment at 1, 2, 3, 4, 6, 8, 10, 12, and 24 h and analysed for drug content by the HPLC method. The mechanism of skin permeation enhancement of valsartan by terpenes treatment was evaluated by Fourier transform infrared spectroscopy (FTIR) analysis and differential scanning calorimetry (DSC). All the investigated terpenes provided a significant (p valsartan flux at a concentration of 1%, and less so at 3% and 5%. The effectiveness of terpenes at 1% concentration was in the following order: anethole > menthone > eugenol with 4.4-, 4.0-, and 3.0-fold enhancement ratio over control, respectively. DSC study showed that the treatment of stratum corneum with anethole shifted endotherm down to lower melting point while FTIR studies revealed that anethole produced maximum decrease in peak height and area than other two terpenes. The investigated terpenes can be successfully used as potential enhancers for the enhancement of skin permeation of lipophilic drug.

Spectra from 2.5-15 μm of tissue phantom materials, optical clearing agents and ex vivo human skin: implications for depth profiling of human skin

International Nuclear Information System (INIS)

Viator, John A; Choi, Bernard; Peavy, George M; Kimel, Sol; Nelson, J Stuart

2003-01-01

Infrared measurements have been used to profile or image biological tissue, including human skin. Usually, analysis of such measurements has assumed that infrared absorption is due to water and collagen. Such an assumption may be reasonable for soft tissue, but introduction of exogenous agents into skin or the measurement of tissue phantoms has raised the question of their infrared absorption spectrum. We used Fourier transform infrared spectroscopy in attenuated total reflection mode to measure the infrared absorption spectra, in the range of 2-15 μm, of water, polyacrylamide, Intralipid, collagen gels, four hyperosmotic clearing agents (glycerol, 1,3-butylene glycol, trimethylolpropane, Topicare TM ), and ex vivo human stratum corneum and dermis. The absorption spectra of the phantom materials were similar to that of water, although additional structure was noted in the range of 6-10 μm. The absorption spectra of the clearing agents were more complex, with molecular absorption bands dominating between 6 and 12 μm. Dermis was similar to water, with collagen structure evident in the 6-10 μm range. Stratum corneum had a significantly lower absorption than dermis due to a lower content of water. These results suggest that the assumption of water-dominated absorption in the 2.5-6 μm range is valid. At longer wavelengths, clearing agent absorption spectra differ significantly from the water spectrum. This spectral information can be used in pulsed photothermal radiometry or utilized in the interpretation of reconstructions in which a constant μ ir is used. In such cases, overestimating μ ir will underestimate chromophore depth and vice versa, although the effect is dependent on actual chromophore depth. (note)

Tolerance of natural baby skin-care products on healthy, full-term infants and toddlers.

Science.gov (United States)

Coret, Catherine D; Suero, Michael B; Tierney, Neena K

2014-01-01

To evaluate the tolerance of baby skin-care products with at least 95% naturally derived ingredients on infants and toddlers. Healthy, full-term infants and toddlers aged 1-36 months were enrolled. In study 1, a lightly fragranced natural baby hair and body wash (n=30), a lightly fragranced natural baby shampoo (n=30), or a lightly fragranced natural baby lotion (n=32) were assessed over 2 weeks. In study 2, a lightly fragranced natural baby hair and body wash and a lightly fragranced natural baby lotion (n=33) were assessed as a regimen over 4 weeks. The wash and shampoo were used three or more times per week, but not more than once daily. Lotions were applied in the morning or after a bath. Clinicians assessed the arms, legs, torso, or scalp for erythema, dryness, peeling/flakiness (study 1 only), tactile roughness, edema (study 1 only), rash/irritation (study 2 only), and overall skin condition (study 2 only) at baseline, week 1, and weeks 2 or 4. Parents completed skin assessment questionnaires. In study 2, stratum corneum hydration was measured. Subjects were monitored for adverse events. No significant changes in clinical grading scores were observed, indicating that all products were well tolerated. By the end of each study, >90% of parents/caregivers believed each product was mild and gentle. In study 2, improvement in stratum corneum hydration was observed (+37% at week 1 and +48% at week 4, Pproduct-related adverse events. The natural baby skin-care products were well tolerated by infants and toddlers when used alone or as part of a skin-care regimen.

[Improvement of rosacea treatment based on the morphological and functional features of the skin].

Science.gov (United States)

Tsiskarishvili, N V; Katsitadze, A G; Tsiskarishvili, Ts I

2013-10-01

Rosacea - a widespread disease sometimes aleak with severe complications, mainly affecting the skin. Irrational and inadequate treatment leads to chronicity of diseases and psychosocial disadaptation of patients. Lately, a clear upward trend in the number of patients in whom in the process of complex treatment manifestations (with the varying degrees of severity) of impaired barrier function of the skin are observed and they need the protection and restoration of the damaged stratum corneum. In patients with rosacea in order to study the function of the facial skin's horny layer we used the skin analyzer BIA (bioimpedance analysis, which in duration of 6 seconds determines the moisture content, oiliness and the softness of the skin) and significant deviations from the norm (decrease in moisture content, fatness and increased roughness) was revealed. These changes were most clearly pronounced in patients with steroid rosacea. To restore the skin barrier the drug "Episofit A" (Laboratory of Evolutionary Dermatology, France) has been used (1-2 times a day for 6 weeks). Evaluation of treatment efficacy was conducted every 2 weeks by means of a scale from 0 to 5 for parameters of dryness, erythema, peeling and expression of subjective feelings. In accordance with received results, using of Episofit A emulsion, especially on the baсkground of long-term treatment with topical steroids, had a pronounced therapeutic effect. Thus, treatment of patients with consideration of morphological and functional features of facial skin, helps to improve the results traditional therapy, and the drug is highly effective means of the new direction in skin care - corneotherapy aimed to reconstruct and protect damaged stratum corneum.

Confocal laser scanning microscopy to estimate nanoparticles’ human skin penetration in vitro

Directory of Open Access Journals (Sweden)

Zou Y

2017-10-01

Full Text Available Ying Zou,1,2,* Anna Celli,2,3,* Hanjiang Zhu,2,* Akram Elmahdy,2 Yachao Cao,2 Xiaoying Hui,2 Howard Maibach2 1Skin & Cosmetic Research Department, Shanghai Skin Disease Hospital, Shanghai, People’s Republic of China; 2Department of Dermatology, School of Medicine, University of California San Francisco, San Francisco, CA, USA; 3San Francisco Veterans Medical Center, San Francisco, CA, USA *These authors contributed equally to this work Objective: With rapid development of nanotechnology, there is increasing interest in nanoparticle (NP application and its safety and efficacy on human skin. In this study, we utilized confocal laser scanning microscopy to estimate NP skin penetration.Methods: Three different-sized polystyrene NPs marked with red fluorescence were applied to human skin, and Calcium Green 5N was used as a counterstain. Dimethyl sulfoxide (DMSO and ethanol were used as alternative vehicles for NPs. Tape stripping was utilized as a barrier-damaged skin model. Skin biopsies dosed with NPs were incubated at 4°C or 37°C for 24 hours and imaged using confocal laser scanning microscopy.Results: NPs were localized in the stratum corneum (SC and hair follicles without penetrating the epidermis/dermis. Barrier alteration with tape stripping and change in incubation temperature did not induce deeper penetration. DMSO enhanced NP SC penetration but ethanol did not.Conclusion: Except with DMSO vehicle, these hydrolyzed polystyrene NPs did not penetrate intact or barrier-damaged human “viable” epidermis. For further clinical relevance, in vivo human skin studies and more sensitive analytic chemical methodology are suggested. Keywords: nanoparticles, skin penetration, stratum corneum, confocal laser scanning microscopy, tape stripping

Melanin fate in the human epidermis: a reassessment of how best to detect and analyse histologically.

Science.gov (United States)

Joly-Tonetti, Nicolas; Wibawa, Judata I D; Bell, Mike; Tobin, Desmond

2016-07-01

Melanin is the predominant pigment responsible for skin colour and is synthesized by the melanocyte in the basal layer of the epidermis and then transferred to surrounding keratinocytes. Despite its optical properties, melanin is barely detectable in unstained sections of human epidermis. However, identification and localization of melanin is of importance for the study of skin pigmentation in health and disease. Current methods for the histologic quantification of melanin are suboptimal and are associated with significant risk of misinterpretation. The aim of this study was to reassess the existing literature and to develop a more effective histological method of melanin quantification in human skin. Moreover, we confirm that Warthin-Starry (WS) stain provides a much more sensitive and more specific melanin detection method than the commonplace Fontana-Masson (FM) stain. For example, WS staining sensitivity allowed the visualization of melanin even in very pale Caucasian skin that was missed by FM or Von Kossa (VK) stains. From our reassessment of the histology-related literature, we conclude that so-called melanin dust is most likely an artifact of discoloration due to non-specific silver deposition in the stratum corneum. Unlike FM and VK, WS was not associated with this non-specific stratum corneum darkening, misinterpreted previously as 'degraded' melanin. Finally, WS melanin particle counts were largely similar to previously reported manual counts by transmission electron microscopy, in contrast to both FM and VK. Together these findings allow us to propose a new histology/Image J-informed method for the accurate and precise quantification of epidermal melanin in skin. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Skin-Derived C-Terminal Filaggrin-2 Fragments Are Pseudomonas aeruginosa-Directed Antimicrobials Targeting Bacterial Replication.

Directory of Open Access Journals (Sweden)

Britta Hansmann

2015-09-01

Full Text Available Soil- and waterborne bacteria such as Pseudomonas aeruginosa are constantly challenging body surfaces. Since infections of healthy skin are unexpectedly rare, we hypothesized that the outermost epidermis, the stratum corneum, and sweat glands directly control the growth of P. aeruginosa by surface-provided antimicrobials. Due to its high abundance in the upper epidermis and eccrine sweat glands, filaggrin-2 (FLG2, a water-insoluble 248 kDa S100 fused-type protein, might possess these innate effector functions. Indeed, recombinant FLG2 C-terminal protein fragments display potent antimicrobial activity against P. aeruginosa and other Pseudomonads. Moreover, upon cultivation on stratum corneum, P. aeruginosa release FLG2 C-terminus-containing FLG2 fragments from insoluble material, indicating liberation of antimicrobially active FLG2 fragments by the bacteria themselves. Analyses of the underlying antimicrobial mechanism reveal that FLG2 C-terminal fragments do not induce pore formation, as known for many other antimicrobial peptides, but membrane blebbing, suggesting an alternative mode of action. The association of the FLG2 fragment with the inner membrane of treated bacteria and its DNA-binding implicated an interference with the bacterial replication that was confirmed by in vitro and in vivo replication assays. Probably through in situ-activation by soil- and waterborne bacteria such as Pseudomonads, FLG2 interferes with the bacterial replication, terminates their growth on skin surface and thus may contributes to the skin's antimicrobial defense shield. The apparent absence of FLG2 at certain body surfaces, as in the lung or of burned skin, would explain their higher susceptibility towards Pseudomonas infections and make FLG2 C-terminal fragments and their derivatives candidates for new Pseudomonas-targeting antimicrobials.

Skin-Derived C-Terminal Filaggrin-2 Fragments Are Pseudomonas aeruginosa-Directed Antimicrobials Targeting Bacterial Replication.

Science.gov (United States)

Hansmann, Britta; Schröder, Jens-Michael; Gerstel, Ulrich

2015-09-01

Soil- and waterborne bacteria such as Pseudomonas aeruginosa are constantly challenging body surfaces. Since infections of healthy skin are unexpectedly rare, we hypothesized that the outermost epidermis, the stratum corneum, and sweat glands directly control the growth of P. aeruginosa by surface-provided antimicrobials. Due to its high abundance in the upper epidermis and eccrine sweat glands, filaggrin-2 (FLG2), a water-insoluble 248 kDa S100 fused-type protein, might possess these innate effector functions. Indeed, recombinant FLG2 C-terminal protein fragments display potent antimicrobial activity against P. aeruginosa and other Pseudomonads. Moreover, upon cultivation on stratum corneum, P. aeruginosa release FLG2 C-terminus-containing FLG2 fragments from insoluble material, indicating liberation of antimicrobially active FLG2 fragments by the bacteria themselves. Analyses of the underlying antimicrobial mechanism reveal that FLG2 C-terminal fragments do not induce pore formation, as known for many other antimicrobial peptides, but membrane blebbing, suggesting an alternative mode of action. The association of the FLG2 fragment with the inner membrane of treated bacteria and its DNA-binding implicated an interference with the bacterial replication that was confirmed by in vitro and in vivo replication assays. Probably through in situ-activation by soil- and waterborne bacteria such as Pseudomonads, FLG2 interferes with the bacterial replication, terminates their growth on skin surface and thus may contributes to the skin's antimicrobial defense shield. The apparent absence of FLG2 at certain body surfaces, as in the lung or of burned skin, would explain their higher susceptibility towards Pseudomonas infections and make FLG2 C-terminal fragments and their derivatives candidates for new Pseudomonas-targeting antimicrobials.

Effect of temperature on sandstone permeability

DEFF Research Database (Denmark)

Rosenbrand, Esther; Kjøller, Claus

Hot water injection in geothermal sandstone aquifers is considered for seasonal energy storage in Denmark. However, an increase in the aquifer temperature might reduce permeability, and thereby increase production costs. An understanding of the factors that control permeability is required in order...... and the Klinkenberg procedure showed the expected correlation between the two measures, however, differences could be around one order of magnitude. In tight gas sandstones, permeability is often sensitive to net stress, which might change due to the pore pressure change in the Klinkenberg procedure. Besides...... affecting the Klinkenberg procedure, the combined effect of slip and changes in permeability would affect production during pressure depletion in tight gas sandstone reservoirs; therefore effects of gas slip and net stress on permeability were combined in a model based on the Klinkenberg equation. A lower...

The pH of the main Brazilian commercial moisturizers and liquid soaps: considerations on the repair of the skin barrier.

Science.gov (United States)

Gonçalves, Giovana M; Brianezi, Gabrielli; Miot, Hélio Amante

2017-01-01

The pH of the skin is slightly acidic (4.6 to 5.8) which is important for appropriate antibacterial, antifungal, constitution of barrier function, as well as structuring and maturation of the stratum corneum. This study aimed to evaluate the pH of the main commercial moisturizers and liquid soaps in Brazil. Thus, pH of the products was quantified by pH meter in three measurements. A total of 38 moisturizers and six commercial liquid soaps were evaluated. Mean pH of 63% and 50% of the moisturizing and liquid soaps presented results above 5.5, disfavoring repair, function, and synthesis of dermal barrier.

The pH of the main Brazilian commercial moisturizers and liquid soaps: considerations on the repair of the skin barrier*

Science.gov (United States)

Gonçalves, Giovana M; Brianezi, Gabrielli; Miot, Hélio Amante

2017-01-01

The pH of the skin is slightly acidic (4.6 to 5.8) which is important for appropriate antibacterial, antifungal, constitution of barrier function, as well as structuring and maturation of the stratum corneum. This study aimed to evaluate the pH of the main commercial moisturizers and liquid soaps in Brazil. Thus, pH of the products was quantified by pH meter in three measurements. A total of 38 moisturizers and six commercial liquid soaps were evaluated. Mean pH of 63% and 50% of the moisturizing and liquid soaps presented results above 5.5, disfavoring repair, function, and synthesis of dermal barrier. PMID:29166523

Defense of cutaneous cells against uv irradiation. II. Restricted photomediated binding of trimethyl psoralen to pigmented skin in vivo

International Nuclear Information System (INIS)

Carter, D.M.; Jegasothy, B.V.; Condit, E.S.

1973-01-01

Distinct differences in grain distribution were seen in autoradiographs of pigmented and nonpigmented skin from spotted guinea-pig ears subjected to photosensitizing conditions by the topical application of tritiated trimethyl psoralen ( 3 H TMP) and exposure to uv irradiation at 365 nm. Grains were localized over cells throughout the epidermis in nonpigmented skin, but they were not seen beneath the stratum corneum in pigmented skin. Since TMP covalently binds to epidermal nucleic acids only after irradiation, these experiments demonstrate that the compacted melanized cells of the outer epidermis shield the DNA of underlying cells by severely restricting the penetration of uv light into the skin. (auth)

Ionophorèse et électroporation : administration cutanée de médicaments et d'ADN

OpenAIRE

Préat, Véronique; Vandermeulen, Gaëlle; Daugimont, Liévin; Wascotte, Valentine

2009-01-01

La peau est une cible intéressante pour l'administration de médicaments et d'ADN qui cependant reste limitée par la faible perméabilité du stratum corneum. L'ionophorèse et l'électroporation ont été largement étudiées afin d'obtenir une administration transdermique. Dans les deux cas, le passage de courant perturbe la perméabilité de la peau et même la perméabilité cellulaire dans le cas précis de l'électroporation. Ces deux techniques permettent d'élargir le spectre des substances administra...

Development of three-dimension microelectrode array for bioelectric measurement using the liquidmetal-micromolding technique

International Nuclear Information System (INIS)

Liu, Ran; Yang, Xueyao; Chen, Weixing; Jin, Cuiyun; Fu, Jingjing; Liu, Jing

2013-01-01

A method of manufacturing three-dimension microneedle electrode arrays is presented in this paper using the micromolding technology with liquid metal at room temperature, based on the physical property of the Bi-In-Sn liquid metal alloy, being its melting point especially low. Observed under scanning electron microscopy, the needle body of the electrode chip manufactured using this method has a good consistency. Skin penetration test in-vitro indicates that the microneedle electrode can pierce the stratum corneum and cross the high-impedance layer to acquire electrical signals. Electrical impedance and polarization voltage experimental results show that the electrode chips have great electric characteristics and meet the practical application demands

Development of three-dimension microelectrode array for bioelectric measurement using the liquidmetal-micromolding technique

Energy Technology Data Exchange (ETDEWEB)

Liu, Ran, E-mail: liuran@tsinghua.edu.cn; Yang, Xueyao; Chen, Weixing [Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084 (China); Jin, Cuiyun; Fu, Jingjing [College of Information Science and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Liu, Jing [Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084 (China); Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

2013-11-04

A method of manufacturing three-dimension microneedle electrode arrays is presented in this paper using the micromolding technology with liquid metal at room temperature, based on the physical property of the Bi-In-Sn liquid metal alloy, being its melting point especially low. Observed under scanning electron microscopy, the needle body of the electrode chip manufactured using this method has a good consistency. Skin penetration test in-vitro indicates that the microneedle electrode can pierce the stratum corneum and cross the high-impedance layer to acquire electrical signals. Electrical impedance and polarization voltage experimental results show that the electrode chips have great electric characteristics and meet the practical application demands.

Structural and biophysical characteristics of human skin in maintaining proper epidermal barrier function

Directory of Open Access Journals (Sweden)

Magdalena Boer

2016-02-01

Full Text Available The complex structure of human skin and its physicochemical properties turn it into an efficient outermost defence line against exogenous factors, and help maintain homeostasis of the human body. This role is played by the epidermal barrier with its major part – stratum corneum. The condition of the epidermal barrier depends on individual and environmental factors. The most important biophysical parameters characterizing the status of this barrier are the skin pH, epidermal hydration, transepidermal water loss and sebum excretion. The knowledge of biophysical skin processes may be useful for the implementation of prophylactic actions whose aim is to restore the barrier function.

The percutaneous permeation of a combination of 0.1% octenidine dihydrochloride and 2% 2-phenoxyethanol (octenisept® through skin of different species in vitro

Directory of Open Access Journals (Sweden)

Kietzmann Manfred

2011-08-01

Full Text Available Abstract Background A water based combination of 0.1% octenidine dihydrochloride and 2% 2 - phenoxyethanol is registered in many European countries as an antiseptic solution (octenisept® for topical treatment with high antimicrobial activity for human use, but octenidine based products have not been registered for veterinary use yet. The aim of the present study was to investigate whether octenidine dihydrochloride or 2 -phenoxyethanol, the two main components of this disinfectant, permeate through animal skin in vitro. Therefore, permeation studies were conducted using Franz-type diffusion cells. 2 ml of the test compound were applied onto 1.77 cm2 split skin of cats, dogs, cows and horses. To simulate wounded skin, cattle skin was treated with adhesive tapes 100 times, as well. Up to an incubation time of 28 hours samples of the acceptor chamber were taken and were analysed by UV-HPLC. Using the method of the external standard, the apparent permeability coefficient, the flux Jmax, and the recovery were calculated. Furthermore, the residues of both components in the skin samples were determined after completion of the diffusion experiment. Results After 28 hours no octenidine dihydrochloride was found in the receptor chamber of intact skin samples, while 2.7% of the topical applied octenidine dihydrochloride permeated through barrier disrupted cattle skin. 2 - phenoxyethanol permeated through all skin samples with the highest permeability in equine, followed by bovine, canine to feline skin. Furthermore, both components were found in the stratum corneum and the dermis of all split skin samples with different amounts in the examined species. Conclusion For 2-phenoxyethanol the systemic impact of the high absorption rate and a potential toxicological risk have to be investigated in further studies. Due to its low absorption rates through the skin, octenidine dihydrochloride is suitable for superficial skin treatment in the examined species.

Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

Energy Technology Data Exchange (ETDEWEB)

Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical–Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

2015-04-15

Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R{sup 2} = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q{sup 2}{sub ext} = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin

Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

International Nuclear Information System (INIS)

Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

2015-01-01

Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R 2 = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q 2 ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin sensitization and

Defining clogging potential for permeable concrete.

Science.gov (United States)

Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R

2018-08-15

Permeable concrete is used to reduce urban flooding as it allows water to flow through normally impermeable infrastructure. It is prone to clogging by particulate matter and predicting the long-term performance of permeable concrete is challenging as there is currently no reliable means of characterising clogging potential. This paper reports on the performance of a range of laboratory-prepared and commercial permeable concretes, close packed glass spheres and aggregate particles of varying size, exposed to different clogging methods to understand this phenomena. New methods were developed to study clogging and define clogging potential. The tests involved applying flowing water containing sand and/or clay in cycles, and measuring the change in permeability. Substantial permeability reductions were observed in all samples, particularly when exposed to sand and clay simultaneously. Three methods were used to define clogging potential based on measuring the initial permeability decay, half-life cycle and number of cycles to full clogging. We show for the first time strong linear correlations between these parameters for a wide range of samples, indicating their use for service-life prediction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Different Methods of Predicting Permeability in Shale

DEFF Research Database (Denmark)

Mbia, Ernest Ncha; Fabricius, Ida Lykke; Krogsbøll, Anette

by two to five orders of magnitudes at lower vertical effective stress below 40 MPa as the content of clay minerals increases causing heterogeneity in shale material. Indirect permeability from consolidation can give maximum and minimum values of shale permeability needed in simulating fluid flow......Permeability is often very difficult to measure or predict in shale lithology. In this work we are determining shale permeability from consolidation tests data using Wissa et al., (1971) approach and comparing the results with predicted permeability from Kozeny’s model. Core and cuttings materials...... effective stress to 9 μD at high vertical effective stress of 100 MPa. The indirect permeability calculated from consolidation tests falls in the same magnitude at higher vertical effective stress, above 40 MPa, as that of the Kozeny model for shale samples with high non-clay content ≥ 70% but are higher...

Novel TGM5 mutations in acral peeling skin syndrome.

Science.gov (United States)

van der Velden, Jaap J A J; van Geel, Michel; Nellen, Ruud G L; Jonkman, Marcel F; McGrath, John A; Nanda, Arti; Sprecher, Eli; van Steensel, Maurice A M; McLean, W H Irwin; Cassidy, Andrew J

2015-04-01

Acral peeling skin syndrome (APSS, MIM #609796) is a rare autosomal recessive disorder characterized by superficial exfoliation and blistering of the volar and dorsal aspects of hands and feet. The level of separation is at the junction of the stratum granulosum and stratum corneum. APSS is caused by mutations in the TGM5 gene encoding transglutaminase-5, which is important for structural integrity of the outermost epidermal layers. The majority of patients originate from Europe and carry a p.(Gly113Cys) mutation in TGM5. In this study, we report both European and non-European families carrying other mutations in the TGM5 gene. In 5 patients, we found 3 novel mutations: c.1001+2_1001+3del, c.1171G>A and c.1498C>T. To confirm their pathogenicity, we performed functional analyses with a transglutaminase activity assay, determined alternative splicing by reverse-transcribed PCR analysis and used databases and in silico prediction tools. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Quantifying porosity, compressibility and permeability in Shale

DEFF Research Database (Denmark)

Mbia, Ernest Ncha; Fabricius, Ida Lykke; Frykman, Peter

strain data. We found that Kozeny's modelled permeability fall in the same order of magnitude with measured permeability for shale rich in kaolinite but overestimates permeability by two to three orders of magnitudes for shale with high content of smectite. The empirical Yang and Aplin model gives good...... permeability estimate comparable to the measured one for shale rich in smectite. This is probably because Yang and Aplin model was calibrated in London clay which is rich in smectite....

Microorganism Removal in Permeable Pavement Parking Lots ...

Science.gov (United States)

Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed that porous asphalt had much lower concentration in monitored infiltrate compared to pervious concrete and permeable interlocking concrete pavers. Concentrations of monitored organisms in infiltrate from porous asphalt were consistently below the bathing water quality standard. Fecal coliform and enterococci exceeded bathing water quality standards more than 72% and 34% of the time for permeable interlocking concrete pavers and pervious concrete, respectively. Purpose is to evaluate the performance of permeable pavement in removing indicator organisms from infiltrating stormwater runoff.

Ultramorphological and histological studies on the tongue of the common kingfisher in relation to its feeding habit

Directory of Open Access Journals (Sweden)

Sh.A. Al-Zahaby

2014-05-01

The tongue of the studied bird is an elongated, tubby and consistent organ of triangular shape of about 8.9 mm in length. It drops in the posterior quarter of the lower part of the very long bill. It is composed of three successive regions; blunt apex, stocky body and root. In addition to the giant conical papillae demarcating the tongue’s body from root, numerous caudally directed spiny conical papillae are differently distributed on the dorsal and lateral surfaces of the lingual body and root. Both papillae appears to help catching and directly swallowing preys, however the apex is covered with superposed foliate papillae. By light microscope, the dorsal lingual epithelium is composed of a keratinized stratified squamous epithelium. The stratum basale is followed by a thick stratum spinosum of polyhedral cells containing some deeply embedded taste buds and gives rise to the stratum corneum cell layer. The loose connective tissue core (lamina propria which embraces some blood vessels and melanocytes forms finger-like dermal papillae of different heights under the epithelium. It also contains branched tubulo-alveolar salivary glands mainly of massive gelatinous mucus secreted on the epithelial surface to facilitate food-intake indicating a close relationship of the lingual structure with the common kingfisher feeding habit which feeds mainly on fishes and aquatic arthropods.

Use of Interface Treatment to Reduce Emissions from Residuals in Lower Permeability Zones to Groundwater flowing Through More Permeable Zones (Invited)

Science.gov (United States)

Johnson, P.; Cavanagh, B.; Clifton, L.; Daniels, E.; Dahlen, P.

2013-12-01

Many soil and groundwater remediation technologies rely on fluid flow for contaminant extraction or reactant delivery (e.g., soil vapor extraction, pump and treat, in situ chemical oxidation, air sparging, enhanced bioremediation). Given that most unconsolidated and consolidated settings have permeability contrasts, the outcome is often preferential treatment of more permeable zones and ineffective treatment of the lower permeability zones. When this happens, post-treatment contaminant emissions from low permeability zone residuals can cause unacceptable long-term impacts to groundwater in the transmissive zones. As complete remediation of the impacted lower permeability zones may not be practicable with conventional technologies, one might explore options that lead to reduction of the contaminant emissions to acceptable levels, rather than full remediation of the lower permeability layers. This could be accomplished either by creating a sustained emission reaction/attenuation zone at the high-low permeability interface, or by creating a clean soil zone extending sufficiently far into the lower permeability layer to cause the necessary reduction in contaminant concentration gradient and diffusive emission. These options are explored in proof-of-concept laboratory-scale physical model experiments. The physical models are prepared with two layers of contrasting permeability and either dissolved matrix storage or nonaqueous phase liquid (NAPL) in the lower permeability layer. A dissolved oxidant is then delivered to the interface via flow across the higher permeability layer and changes in contaminant emissions from the low permeability zone are monitored before, during, and after oxidant delivery. The use of three oxidants (dissolved oxygen, hydrogen peroxide and sodium persulfate) for treatment of emissions from petroleum hydrocarbon residuals is examined.

Cross stratum resources protection in fog-computing-based radio over fiber networks for 5G services

Science.gov (United States)

Guo, Shaoyong; Shao, Sujie; Wang, Yao; Yang, Hui

2017-09-01

In order to meet the requirement of internet of things (IoT) and 5G, the cloud radio access network is a paradigm which converges all base stations computational resources into a cloud baseband unit (BBU) pool, while the distributed radio frequency signals are collected by remote radio head (RRH). A precondition for centralized processing in the BBU pool is an interconnection fronthaul network with high capacity and low delay. However, it has become more complex and frequent in the interaction between RRH and BBU and resource scheduling among BBUs in cloud. Cloud radio over fiber network has been proposed in our previous work already. In order to overcome the complexity and latency, in this paper, we first present a novel cross stratum resources protection (CSRP) architecture in fog-computing-based radio over fiber networks (F-RoFN) for 5G services. Additionally, a cross stratum protection (CSP) scheme considering the network survivability is introduced in the proposed architecture. The CSRP with CSP scheme can effectively pull the remote processing resource locally to implement the cooperative radio resource management, enhance the responsiveness and resilience to the dynamic end-to-end 5G service demands, and globally optimize optical network, wireless and fog resources. The feasibility and efficiency of the proposed architecture with CSP scheme are verified on our software defined networking testbed in terms of service latency, transmission success rate, resource occupation rate and blocking probability.

Controlling DC permeability in cast steels

Energy Technology Data Exchange (ETDEWEB)

Sumner, Aaran, E-mail: aaran.sumner@nottingham.ac.uk [University of Nottingham, Nottingham University Park Campus, Nottingham NG7 2RD, England (United Kingdom); Gerada, Chris, E-mail: chris.gerada@nottingham.ac.uk [Electrical Machines, University of Nottingham, Tower Building, Nottingham NG7 2RD, England (United Kingdom); Brown, Neil, E-mail: neil.brown@cummins.com [Advanced Electrical Machines Research and Technology at Cummins Power Generation, Peterborough PE2 6FZ, England (United Kingdom); Clare, Adam, E-mail: adam.clare@nottingham.ac.uk [Advanced Manufacturing, University of Nottingham, University Park Campus, Nottingham NG7 2RD, England (United Kingdom)

2017-05-01

Annealing (at multiple cooling rates) and quenching (with tempering) was performed on specimens of cast steel of varying composition. The aim was to devise a method for selecting the steel with the highest permeability, from any given range of steels, and then increasing the permeability by heat treatment. Metallographic samples were imaged using optical microscopy to show the effect of the applied heat treatments on the microstructure. Commonly cast steels can have DC permeability altered by the careful selection of a heat treatment. Increases of up to 381% were achieved by annealing using a cooling rate of 6.0 °C/min. Annealing was found to cause the carbon present in the steel to migrate from grain boundaries and from within ferrite crystals into adjacent pearlite crystals. The migration of the carbon resulted in less carbon at grain boundaries and within ferrite crystals reducing the number of pinning sites between magnetic domains. This gives rise to a higher permeability. Quenching then tempering was found to cause the formation of small ferrite crystals with the carbon content of the steel predominately held in the martensitic crystal structures. The results show that with any given range of steel compositions the highest baseline DC permeability will be found with the steel that has the highest iron content and the lowest carbon content. For the samples tested in this paper a cooling rate of 4.5 °C/min resulted in the relative permeability of the sample with the highest baseline permeability, AS4, increasing from 783 to 1479 at 0.5 T. This paper shows how heat treatments commonly applied to hypoeutectoid cast steels, to improve their mechanical performance, can be used to also enhance electromagnetic properties of these alloys. The use of cast steels allows the creation of DC components for electrical machines not possible by the widely used method of stacking of electrical grade sheet steels. - Highlights: • A range of structural steels had their

Controlling DC permeability in cast steels

International Nuclear Information System (INIS)

Sumner, Aaran; Gerada, Chris; Brown, Neil; Clare, Adam

2017-01-01

Annealing (at multiple cooling rates) and quenching (with tempering) was performed on specimens of cast steel of varying composition. The aim was to devise a method for selecting the steel with the highest permeability, from any given range of steels, and then increasing the permeability by heat treatment. Metallographic samples were imaged using optical microscopy to show the effect of the applied heat treatments on the microstructure. Commonly cast steels can have DC permeability altered by the careful selection of a heat treatment. Increases of up to 381% were achieved by annealing using a cooling rate of 6.0 °C/min. Annealing was found to cause the carbon present in the steel to migrate from grain boundaries and from within ferrite crystals into adjacent pearlite crystals. The migration of the carbon resulted in less carbon at grain boundaries and within ferrite crystals reducing the number of pinning sites between magnetic domains. This gives rise to a higher permeability. Quenching then tempering was found to cause the formation of small ferrite crystals with the carbon content of the steel predominately held in the martensitic crystal structures. The results show that with any given range of steel compositions the highest baseline DC permeability will be found with the steel that has the highest iron content and the lowest carbon content. For the samples tested in this paper a cooling rate of 4.5 °C/min resulted in the relative permeability of the sample with the highest baseline permeability, AS4, increasing from 783 to 1479 at 0.5 T. This paper shows how heat treatments commonly applied to hypoeutectoid cast steels, to improve their mechanical performance, can be used to also enhance electromagnetic properties of these alloys. The use of cast steels allows the creation of DC components for electrical machines not possible by the widely used method of stacking of electrical grade sheet steels. - Highlights: • A range of structural steels had their

The distribution of free calcium ions in the cholesteatoma epithelium

DEFF Research Database (Denmark)

Svane-Knudsen, Viggo; Rasmussen, Gurli; Ottosen, Peter D

2005-01-01

The distribution of free calcium ions in normal skin and cholesteatoma epithelium was investigated using the oxalate precipitation method. In agreement with previous observations, we could demonstrate a calcium ion gradient in normal epidermis where the cells in stratum basale and spinosum reside...... appeared where oblong accumulations of free calcium ions were found basally in the stratum. These findings provide evidence that fluctuations in epidermal calcium in cholesteatoma epithelium may underlie the abnormal desquamation, may contribute to the formation of an abnormal permeability barrier and may...

Frictional stability-permeability relationships for fractures in shales

Science.gov (United States)

Fang, Yi; Elsworth, Derek; Wang, Chaoyi; Ishibashi, Takuya; Fitts, Jeffrey P.

2017-03-01

There is wide concern that fluid injection in the subsurface, such as for the stimulation of shale reservoirs or for geological CO2 sequestration (GCS), has the potential to induce seismicity that may change reservoir permeability due to fault slip. However, the impact of induced seismicity on fracture permeability evolution remains unclear due to the spectrum of modes of fault reactivation (e.g., stable versus unstable). As seismicity is controlled by the frictional response of fractures, we explore friction-stability-permeability relationships through the concurrent measurement of frictional and hydraulic properties of artificial fractures in Green River shale (GRS) and Opalinus shale (OPS). We observe that carbonate-rich GRS shows higher frictional strength but weak neutral frictional stability. The GRS fracture permeability declines during shearing while an increased sliding velocity reduces the rate of permeability decline. By comparison, the phyllosilicate-rich OPS has lower friction and strong stability while the fracture permeability is reduced due to the swelling behavior that dominates over the shearing induced permeability reduction. Hence, we conclude that the friction-stability-permeability relationship of a fracture is largely controlled by mineral composition and that shale mineral compositions with strong frictional stability may be particularly subject to permanent permeability reduction during fluid infiltration.

Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

Science.gov (United States)

Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

2015-01-01

Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R2=0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q2ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. PMID:25560673

Transverse Chemotactic Migration of Bacteria from High to Low Permeability Regions in a Dual Permeability Porous Microfluidic Device

Science.gov (United States)

Singh, R.; Olson, M. S.

2011-12-01

Low permeability regions sandwiched between high permeability regions such as clay lenses are difficult to treat using conventional treatment methods. Trace concentrations of contaminants such as non-aqueous phase liquids (NAPLs) remain trapped in these regions and over the time diffuse out into surrounding water thereby acting as a long term source of groundwater contamination. Bacterial chemotaxis (directed migration toward a contaminant source), may be helpful in enhancing bioremediation of such contaminated sites. This study is focused on simulating a two-dimensional dual-permeability groundwater contamination scenario using microfluidic devices and evaluating transverse chemotactic migration of bacteria from high to low permeability regions. A novel bi-layer polydimethylsiloxane (PDMS) microfluidic device was fabricated using photolithography and soft lithography techniques to simulate contamination of a dual- permeability region due to leakage from an underground storage tank into a low permeability region. This device consists of a porous channel through which a bacterial suspension (Escherchia Coli HCB33) is flown and another channel for injecting contaminant/chemo-attractant (DL-aspertic acid) into the porous channel. The pore arrangement in the porous channel contains a 2-D low permeability region surrounded by high permeability regions on both sides. Experiments were performed under chemotactic and non-chemotactic (replacing attractant with buffer solution in the non porous channel) conditions. Images were captured in transverse pore throats at cross-sections 4.9, 9.8, and 19.6 mm downstream from the attractant injection point and bacteria were enumerated in the middle of each pore throat. Bacterial chemotaxis was quantified in terms of the change in relative bacterial counts in each pore throat at cross-sections 9.8 and 19.6 mm with respect to counts at the cross-section at 4.9 mm. Under non-chemotactic conditions, relative bacterial count was observed

Modelling of water permeability in cementitious materials

DEFF Research Database (Denmark)

Guang, Ye; Lura, Pietro; van Breugel, K.

2006-01-01

This paper presents a network model to predict the permeability of cement paste from a numerical simulation of its microstructure. Based on a linked list pore network structure, the effective hydraulic conductivity is estimated and the fluid flow is calculated according to the Hagen-Poiseuille law....... The pressure gradient at all nodes is calculated with the Gauss elimination method and the absolute permeability of the pore network is calculated directly from Darcy's law. Finally, the permeability model is validated by comparison with direct water permeability measurements. According to this model...

Bentonite Permeability at Elevated Temperature

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Katherine A. Daniels

2017-01-01

Full Text Available Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity and reduced sealing performance. The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. The experiments were conducted in two sets of purpose-built, temperature controlled apparatus, designed to simulate isotropic pressure and constant volume conditions within the testing range of 4–6 MPa average effective stress. The response of bentonite during thermal loading at temperatures up to 200 °C was investigated, extending the previously considered temperature range. The results provide details of bentonite’s intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. We find that bentonite’s hydraulic properties are sensitive to thermal loading and the type of imposed boundary condition. However, the permeability change is not large and can mostly be accounted for by water viscosity changes. Thus, under 150 °C, temperature has a minimal impact on bentonite’s hydraulic permeability.

Negative permeability from random particle composites

Energy Technology Data Exchange (ETDEWEB)

Hussain, Shahid, E-mail: shussain2@qinetiq.com

2017-04-15

Artificial media, such as those composed of periodically-spaced wires for negative permittivity and split ring resonators for negative permeability have been extensively investigated for negative refractive index (NRI) applications (Smith et al., 2004; Pendry et al., 1999) [1,2]. This paper presents an alternative method for producing negative permeability: granular (or particulate) composites incorporating magnetic fillers. Artificial media, such as split-ring resonators, are designed to produce a magnetic resonance feature, which results in negative permeability over a narrow frequency range about the resonance frequency. The position of the feature is dependent upon the size of the inclusion. The material in this case is anisotropic, such that the feature is only observable when the materials are orientated in a specific direction relative to the applied field. A similar resonance can be generated in magnetic granular (particulate) materials: ferromagnetic resonance from the natural spin resonance of particles. Although the theoretical resonance profiles in granular composites shows the permeability dipping to negative values, this is rarely observed experimentally due to resonance damping effects. Results are presented for iron in spherical form and in flake form, dispersed in insulating host matrices. The two particle shapes show different permeability performance, with the magnetic flakes producing a negative contribution. This is attributed to the stronger coupling with the magnetic field resulting from the high aspect ratio of the flakes. The accompanying ferromagnetic resonance is strong enough to overcome the effects of damping and produce negative permeability. The size of random particle composites is not dictated by the wavelength of the applied field, so the materials are potentially much thinner than other, more traditional artificial composites at microwave frequencies. - Highlights: • Negative permeability from random particle composites is

Permeability enhancement by shock cooling

Science.gov (United States)

Griffiths, Luke; Heap, Michael; Reuschlé, Thierry; Baud, Patrick; Schmittbuhl, Jean

2015-04-01

The permeability of an efficient reservoir, e.g. a geothermal reservoir, should be sufficient to permit the circulation of fluids. Generally speaking, permeability decreases over the life cycle of the geothermal system. As a result, is usually necessary to artificially maintain and enhance the natural permeability of these systems. One of the methods of enhancement -- studied here -- is thermal stimulation (injecting cold water at low pressure). This goal of this method is to encourage new thermal cracks within the reservoir host rocks, thereby increasing reservoir permeability. To investigate the development of thermal microcracking in the laboratory we selected two granites: a fine-grained (Garibaldi Grey granite, grain size = 0.5 mm) and a course-grained granite (Lanhelin granite, grain size = 2 mm). Both granites have an initial porosity of about 1%. Our samples were heated to a range of temperatures (100-1000 °C) and were either cooled slowly (1 °C/min) or shock cooled (100 °C/s). A systematic microstructural (2D crack area density, using standard stereological techniques, and 3D BET specific surface area measurements) and rock physical property (porosity, P-wave velocity, uniaxial compressive strength, and permeability) analysis was undertaken to understand the influence of slow and shock cooling on our reservoir granites. Microstructurally, we observe that the 2D crack surface area per unit volume and the specific surface area increase as a result of thermal stressing, and, for the same maximum temperature, crack surface area is higher in the shock cooled samples. This observation is echoed by our rock physical property measurements: we see greater changes for the shock cooled samples. We can conclude that shock cooling is an extremely efficient method of generating thermal microcracks and modifying rock physical properties. Our study highlights that thermal treatments are likely to be an efficient method for the "matrix" permeability enhancement of

Comprehensive evaluation of carboxylated nanodiamond as a topical drug delivery system.

Science.gov (United States)

Lim, Dae Gon; Kim, Ki Hyun; Kang, Eunah; Lim, Sun Hee; Ricci, Jeremy; Sung, Si Kwon; Kwon, Myoung Taek; Jeong, Seong Hoon

2016-01-01

The best strategy in the development of topical drug delivery systems may be to facilitate the permeation of drugs without any harmful effects, while staying on the skin surface and maintaining stability of the system. Nanodiamonds (NDs) play a key role with their excellent physicochemical properties, including high biocompatibility, physical adsorption, reactive oxygen species (ROS) scavenging capability, and photostabilizing activity. Z-average sizes of carboxylated ND (ND-COOH) agglutinate decreased significantly as the pH increased. Fluorescein-conjugated ND was observed only on the stratum corneum, and no sample diffused into the dermal layer even after 48 hours. Moreover, ND-COOH and ND-COOH/eugenol complex did not show significant toxic effects on murine macrophage cells. ND improved in vitro skin permeation >50% acting as a "drug reservoir" to maintain a high drug concentration in the donor chamber, which was supported by quartz crystal microbalance results. Moreover, ND-COOH could adsorb a drug amount equivalent to 80% of its own weight. A photostability study showed that ND-COOH increased the photostability ~47% with regard to rate constant of the eugenol itself. A significant decrease in ROS was observed in the ND-COOH and ND-COOH/eugenol complex compared with the negative control during intracellular ROS assay. Moreover, ROS and cupric reducing antioxidant capacity evaluation showed that ND-COOH had synergistic effects of antioxidation with eugenol. Therefore, ND-COOH could be used as an excellent topical drug delivery system with improved permeability, higher stability, and minimized safety issue.

Geochemical assessment of application effectiveness of the loess-like loamy stratum for shielding phytotoxic mining rock in the Western Donets Basin

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M. M. Kharitonov

2006-03-01

Full Text Available Main environmental threats of the excavated rocks and gobs in theWestern Donbassare pollution of soils and subterranean waters by toxic salts and heavy metals. Use of the three-layered models with a stratum of protective shield of the loess-like loamy soil for the restoration considerably decreases this negative impact.

Surface-subsurface turbulent interaction at the interface of a permeable bed: influence of the wall permeability

Science.gov (United States)

Kim, T.; Blois, G.; Best, J.; Christensen, K. T.

2017-12-01

Coarse-gravel river beds possess a high degree of permeability. Flow interactions between surface and subsurface flow across the bed interface is key to a number of natural processes occurring in the hyporheic zone. In fact, it is increasingly recognized that these interactions drive mass, momentum and energy transport across the interface, and consequently control biochemical processes as well as stability of sediments. The current study explores the role of the wall permeability in surface and subsurface flow interaction under controlled experimental conditions on a physical model of a gravel bed. The present wall model was constructed by five layers of cubically arranged spheres (d=25.4mm, where d is a diameter) providing 48% of porosity. Surface topography was removed by cutting half of a diameter on the top layer of spheres to render the flow surface smooth and highlight the impact of the permeability on the overlying flow. An impermeable smooth wall was also considered as a baseline of comparison for the permeable wall flow. To obtain basic flow statistics, low-frame-rate high-resolution PIV measurements were performed first in the streamwise-wall-normal (x-y) plane and refractive-index matching was employed to optically access the flow within the permeable wall. Time-resolved PIV experiments in the same facility were followed to investigate the flow interaction across the wall interface in sptaio-temporal domain. In this paper, a detailed analysis of the first and second order velocity statistics as well as the amplitude modulation for the flow overlying the permeable smooth wall will be presented.

In vitro studies of cutaneous retention of magnetic nanoemulsion loaded with zinc phthalocyanine for synergic use in skin cancer treatment

International Nuclear Information System (INIS)

Primo, Fernando L.; Rodrigues, Marcilene M.A.; Simioni, Andreza R.; Bentley, Maria V.L.B.; Morais, Paulo C.; Tedesco, Antonio C.

2008-01-01

In this study was developed a new nano drug delivery system (NDDS) based on association of biodegradable surfactants with biocompatible magnetic fluid of maguemita citrate derivative. This formulation consists in a magnetic emulsion with nanostructured colloidal particles. Preliminary in vitro experiments showed that the formulation presents a great potential for synergic application in the topical release of photosensitizer drug (PS) and excellent target tissue properties in the photodynamic therapy (PDT) combined with hyperthermia (HPT) protocols. The physical chemistry characterization and in vitro assays were carried out by Zn(II) Phtalocyanine (ZnPc) photosensitizer incorporated into NDDS in the absence and the presence of magnetic fluid, showed good results and high biocompatibility. In vitro experiments were accomplished by tape-stripping protocols for quantification of drug association with different skin tissue layers. This technique is a classical method for analyses of drug release in stratum corneum and epidermis+dermis skin layers. The NDDS formulations were applied directly in pig skin (tissue model) fixed in the cell's Franz device with receptor medium container with a PBS/EtOH 20% solution (10 mM, pH 7.4) at 37 deg. C. After 12 h of topical administration stratum corneum was removed from fifty tapes and the ZnPc retained was evaluated by solvent extraction in dimetil-sulphoxide under ultrasonic bath. These results indicated that magnetic nanoemulsion (MNE) increase the drug release on the deeper skin layers when compared with classical formulation in the absence of magnetic particles. This could be related with the increase of biocompatibility of NDDS due to the great affinity for the polar extracelullar matrix in the skin and also for the increase in the drug partition inside of corneocites wall

Two very long chain fatty acid acyl-CoA synthetase genes, acs-20 and acs-22, have roles in the cuticle surface barrier in Caenorhabditis elegans.

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Eriko Kage-Nakadai

Full Text Available In multicellular organisms, the surface barrier is essential for maintaining the internal environment. In mammals, the barrier is the stratum corneum. Fatty acid transport protein 4 (FATP4 is a key factor involved in forming the stratum corneum barrier. Mice lacking Fatp4 display early neonatal lethality with features such as tight, thick, and shiny skin, and a defective skin barrier. These symptoms are strikingly similar to those of a human skin disease called restrictive dermopathy. FATP4 is a member of the FATP family that possesses acyl-CoA synthetase activity for very long chain fatty acids. How Fatp4 contributes to skin barrier function, however, remains to be elucidated. In the present study, we characterized two Caenorhabditis elegans genes, acs-20 and acs-22, that are homologous to mammalian FATPs. Animals with mutant acs-20 exhibited defects in the cuticle barrier, which normally prevents the penetration of small molecules. acs-20 mutant animals also exhibited abnormalities in the cuticle structure, but not in epidermal cell fate or cell integrity. The acs-22 mutants rarely showed a barrier defect, whereas acs-20;acs-22 double mutants had severely disrupted barrier function. Moreover, the barrier defects of acs-20 and acs-20;acs-22 mutants were rescued by acs-20, acs-22, or human Fatp4 transgenes. We further demonstrated that the incorporation of exogenous very long chain fatty acids into sphingomyelin was reduced in acs-20 and acs-22 mutants. These findings indicate that C. elegans Fatp4 homologue(s have a crucial role in the surface barrier function and this model might be useful for studying the fundamental molecular mechanisms underlying human skin barrier and relevant diseases.

TRIBOLOGY OF BIO-INSPIRED NANOWRINKLED FILMS ON ULTRASOFT SUBSTRATES

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Juergen M. Lackner

2013-03-01

Full Text Available Biomimetic design of new materials uses nature as antetype, learning from billions of years of evolution. This work emphasizes the mechanical and tribological properties of skin, combining both hardness and wear resistance of its surface (the stratum corneum with high elasticity of the bulk (epidermis, dermis, hypodermis. The key for combination of such opposite properties is wrinkling, being consequence of intrinsic stresses in the bulk (soft tissue: Tribological contact to counterparts below the stress threshold for tissue trauma occurs on the thick hard stratum corneum layer pads, while tensile loads smooth out wrinkles in between these pads. Similar mechanism offers high tribological resistance to hard films on soft, flexible polymers, which is shown for diamond-like carbon (DLC and titanium nitride thin films on ultrasoft polyurethane and harder polycarbonate substrates. The choice of these two compared substrate materials will show that ultra-soft substrate materials are decisive for the distinct tribological material. Hierarchical wrinkled structures of films on these substrates are due to high intrinsic compressive stress, which evolves during high energetic film growth. Incremental relaxation of these stresses occurs by compound deformation of film and elastic substrate surface, appearing in hierarchical nano-wrinkles. Nano-wrinkled topographies enable high elastic deformability of thin hard films, while overstressing results in zigzag film fracture along larger hierarchical wrinkle structures. Tribologically, these fracture mechanisms are highly important for ploughing and sliding of sharp and flat counterparts on hard-coated ultra-soft substrates like polyurethane. Concentration of polyurethane deformation under the applied normal loads occurs below these zigzag cracks. Unloading closes these cracks again. Even cyclic testing do not lead to film delamination and retain low friction behavior, if the adhesion to the substrate is high

Evaluation of biophysical skin parameters and assessment of hair growth in patients with acne treated with isotretinoin.

Science.gov (United States)

Kmieć, Małgorzata L; Pajor, Anna; Broniarczyk-Dyła, Grażyna

2013-12-01

Treatment of the severe forms of acne vulgaris remains a challenge. Isotretinoin is a drug often used in these cases. Retinoids affect the mechanisms that play a role in the pathogenesis of acne, reduce the production of sebum and sizes of the sebaceous glands. However, isotretinoin appears to have undesirable side effects in the skin, mucous membranes and hair. THE AIM OF THIS STUDY WAS TO ASSESS THE EFFECT OF ACNE VULGARIS TREATMENT WITH ISOTRETINOIN ON BIOPHYSICAL SKIN PARAMETERS: skin sebum and stratum corneum hydration levels, transepidermal water loss values, pH, erythema and hair growth parameters: total number, density and proportion of anagen hair. THE STUDY INCLUDED THIRTY PATIENTS WITH ACNE TYPES: papulopustular, conglobata and phlegmonosa. Patients were treated with isotretinoin at a dose of 0.5-1.0 mg/kg/day for a period of 4-7 months. The measurements of skin biophysical parameters were performed before and after the treatment using Sebumeter SM815, Corneometer CM825, Tewameter TM300, MX Mexameter MX18 and Skin-pH-Meter PH908. Hair growth parameters were evaluated with FotoFinder Dermoscope using the TrichoScan Professional V3.0.8.76 software. The results of biophysical skin parameter measurements after the treatment showed a reduction in the severity of seborrhea. However, the skin was dry, which confirmed a lowered degree of stratum corneum hydration and an increase in transepidermal water loss values. Moreover, severity of erythema, an increase in pH value, and variations in selected hair growth parameters: decrease in total count, density and proportion of anagen hair were demonstrated. The reduction in the skin sebum levels was observed after the treatment. There was dryness of the skin, which was confirmed by biophysical skin parameter measurements. Changes in the hair growth parameters showed telogen effluvium hair loss.

Transdermal microconduits by microscission for drug delivery and sample acquisition

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Anderson R

2004-04-01

Full Text Available Abstract Background Painless, rapid, controlled, minimally invasive molecular transport across human skin for drug delivery and analyte acquisition is of widespread interest. Creation of microconduits through the stratum corneum and epidermis is achieved by stochastic scissioning events localized to typically 250 μm diameter areas of human skin in vivo. Methods Microscissioning is achieved by a limited flux of accelerated gas: 25 μm inert particles passing through the aperture in a mask held against the stratum corneum. The particles scize (cut tissue, which is removed by the gas flow with the sensation of a gentle stream of air against the skin. The resulting microconduit is fully open and may be between 50 and 200 μm deep. Results In vivo adult human tests show that microconduits reduce the electrical impedance between two ECG electrodes from approximately 4,000 Ω to 500 Ω. Drug delivery has been demonstrated in vivo by applying lidocaine to a microconduit from a cotton swab. Sharp point probing demonstrated full anaesthesia around the site within three minutes. Topical application without the microconduit required approximately 1.5 hours. Approximately 180 μm deep microconduits in vivo yielded blood sample volumes of several μl, with a faint pricking sensation as blood enters tissue. Blood glucose measurements were taken with two commercial monitoring systems. Microconduits are invisible to the unaided eye, developing a slight erythematous macule that disappears over days. Conclusion Microscissioned microconduits may provide a minimally invasive basis for delivery of any size molecule, and for extraction of interstitial fluid and blood samples. Such microconduits reduce through-skin electrical impedance, have controllable diameter and depth, are fully open and, after healing, no foreign bodies were visible using through-skin confocal microscopy. In subjects to date, microscissioning is painless and rapid.

Skin condition and its relationship to systemic inflammation in chronic obstructive pulmonary disease.

Science.gov (United States)

Majewski, Sebastian; Pietrzak, Anna; Tworek, Damian; Szewczyk, Karolina; Kumor-Kisielewska, Anna; Kurmanowska, Zofia; Górski, Paweł; Zalewska-Janowska, Anna; Piotrowski, Wojciech Jerzy

2017-01-01

The systemic (extrapulmonary) effects and comorbidities of chronic obstructive pulmonary disease (COPD) contribute substantially to its burden. The supposed link between COPD and its systemic effects on distal organs could be due to the low-grade systemic inflammation. The aim of this study was to investigate whether the systemic inflammation may influence the skin condition in COPD patients. Forty patients with confirmed diagnosis of COPD and a control group consisting of 30 healthy smokers and 20 healthy never-smokers were studied. Transepidermal water loss, stratum corneum hydration, skin sebum content, melanin index, erythema index, and skin temperature were measured with worldwide-acknowledged biophysical measuring methods at the volar forearm of all participants using a multifunctional skin physiology monitor. Biomarkers of systemic inflammation, including high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α), were measured in serum using commercially available enzyme-linked immunosorbent assays. There were significant differences between COPD patients and healthy never-smokers in skin temperature, melanin index, sebum content, and hydration level ( P skin measured. The mean levels of hsCRP and IL-6 in serum were significantly higher in COPD patients and healthy smokers in comparison with healthy never-smokers. There were significant correlations between skin temperature and serum hsCRP ( R =0.40; P =0.02) as well as skin temperature and serum IL-6 ( R =0.49; P =0.005) in smokers. Stratum corneum hydration correlated significantly with serum TNF-α ( R =0.37; P =0.01) in COPD patients. Differences noted in several skin biophysical properties and biomarkers of systemic inflammation between COPD patients, smokers, and healthy never-smokers may suggest a possible link between smoking-driven, low-grade systemic inflammation, and the overall skin condition.

In vitro prediction of in vivo skin damage associated with the wiping of dry tissue against skin.

Science.gov (United States)

Koenig, David W; Dvoracek, Barb; Vongsa, Rebecca

2013-02-01

The ideal gentle cleansing product is one that effectively removes soils while minimizing damage to the skin. Thus, measuring physical abrasion caused by cleansing tissues is critical to the continued development of gentle cleansing products. Current analysis of cleansing materials for skin gentleness is time consuming and requires expensive human subject testing. This report describes the development of a rapid and inexpensive bench assay for the assessment of skin abrasion caused by wiping. Coefficient of friction (COF) evaluations using bench methods were compared with results from clinical studies of repeated wiping and with confocal visualizations of excised skin. A Monitor/Slip and Friction instrument (model 32-06; TMI, Amityville, NY, USA) was used to measure tissue friction on simulated skin (Vitro-Skin, N19-5X; IMS, Milford, CT, USA). Clinical data from a 4-day repetitive forearm wiping study measuring transepidermal water loss (TEWL) in 30 subjects was compared with results from the bench top assay. In addition, excised skin samples were also treated using the COF bench assay and examined using confocal microscopy to visualize stratum corneum damage caused by wiping. Using the bench COF assay, we were able to distinguish between bath tissue codes by comparing average static friction value (ASFV) for the test codes, where lower ASFV indicated less abrasive tissue. The ASFV followed the same gentleness trend observed in the clinical study. Confocal microscopy of excised skin wiped with the same materials indicated stratum corneum damage consistent with the bench COF and clinical TEWL observations. We observed significant correlation between bench and clinical methods for measuring skin damage caused by wiping of skin with tissue. The bench method will facilitate rapid and inexpensive skin gentleness assessment of cleansing materials. © 2012 John Wiley & Sons A/S.

Tribology of bio-inspired nanowrinkled films on ultrasoft substrates.

Science.gov (United States)

Lackner, Juergen M; Waldhauser, Wolfgang; Major, Lukasz; Teichert, Christian; Hartmann, Paul

2013-01-01

Biomimetic design of new materials uses nature as antetype, learning from billions of years of evolution. This work emphasizes the mechanical and tribological properties of skin, combining both hardness and wear resistance of its surface (the stratum corneum) with high elasticity of the bulk (epidermis, dermis, hypodermis). The key for combination of such opposite properties is wrinkling, being consequence of intrinsic stresses in the bulk (soft tissue): Tribological contact to counterparts below the stress threshold for tissue trauma occurs on the thick hard stratum corneum layer pads, while tensile loads smooth out wrinkles in between these pads. Similar mechanism offers high tribological resistance to hard films on soft, flexible polymers, which is shown for diamond-like carbon (DLC) and titanium nitride thin films on ultrasoft polyurethane and harder polycarbonate substrates. The choice of these two compared substrate materials will show that ultra-soft substrate materials are decisive for the distinct tribological material. Hierarchical wrinkled structures of films on these substrates are due to high intrinsic compressive stress, which evolves during high energetic film growth. Incremental relaxation of these stresses occurs by compound deformation of film and elastic substrate surface, appearing in hierarchical nano-wrinkles. Nano-wrinkled topographies enable high elastic deformability of thin hard films, while overstressing results in zigzag film fracture along larger hierarchical wrinkle structures. Tribologically, these fracture mechanisms are highly important for ploughing and sliding of sharp and flat counterparts on hard-coated ultra-soft substrates like polyurethane. Concentration of polyurethane deformation under the applied normal loads occurs below these zigzag cracks. Unloading closes these cracks again. Even cyclic testing do not lead to film delamination and retain low friction behavior, if the adhesion to the substrate is high and the initial

Nanoporous Microneedle Arrays Effectively Induce Antibody Responses against Diphtheria and Tetanus Toxoid

Science.gov (United States)

de Groot, Anne Marit; Platteel, Anouk C. M.; Kuijt, Nico; van Kooten, Peter J. S.; Vos, Pieter Jan; Sijts, Alice J. A. M.; van der Maaden, Koen

2017-01-01

The skin is immunologically very potent because of the high number of antigen-presenting cells in the dermis and epidermis, and is therefore considered to be very suitable for vaccination. However, the skin’s physical barrier, the stratum corneum, prevents foreign substances, including vaccines, from entering the skin. Microneedles, which are needle-like structures with dimensions in the micrometer range, form a relatively new approach to circumvent the stratum corneum, allowing for minimally invasive and pain-free vaccination. In this study, we tested ceramic nanoporous microneedle arrays (npMNAs), representing a novel microneedle-based drug delivery technology, for their ability to deliver the subunit vaccines diphtheria toxoid (DT) and tetanus toxoid (TT) intradermally. First, the piercing ability of the ceramic (alumina) npMNAs, which contained over 100 microneedles per array, a length of 475 µm, and an average pore size of 80 nm, was evaluated in mouse skin. Then, the hydrodynamic diameters of DT and TT and the loading of DT, TT, and imiquimod into, and subsequent release from the npMNAs were assessed in vitro. It was shown that DT and TT were successfully loaded into the tips of the ceramic nanoporous microneedles, and by using near-infrared fluorescently labeled antigens, we found that DT and TT were released following piercing of the antigen-loaded npMNAs into ex vivo murine skin. Finally, the application of DT- and TT-loaded npMNAs onto mouse skin in vivo led to the induction of antigen-specific antibodies, with titers similar to those obtained upon subcutaneous immunization with a similar dose. In conclusion, we show for the first time, the potential of npMNAs for intradermal (ID) immunization with subunit vaccines, which opens possibilities for future ID vaccination designs. PMID:29375544

Nanoporous Microneedle Arrays Effectively Induce Antibody Responses against Diphtheria and Tetanus Toxoid.

Science.gov (United States)

de Groot, Anne Marit; Platteel, Anouk C M; Kuijt, Nico; van Kooten, Peter J S; Vos, Pieter Jan; Sijts, Alice J A M; van der Maaden, Koen

2017-01-01

The skin is immunologically very potent because of the high number of antigen-presenting cells in the dermis and epidermis, and is therefore considered to be very suitable for vaccination. However, the skin's physical barrier, the stratum corneum, prevents foreign substances, including vaccines, from entering the skin. Microneedles, which are needle-like structures with dimensions in the micrometer range, form a relatively new approach to circumvent the stratum corneum, allowing for minimally invasive and pain-free vaccination. In this study, we tested ceramic nanoporous microneedle arrays (npMNAs), representing a novel microneedle-based drug delivery technology, for their ability to deliver the subunit vaccines diphtheria toxoid (DT) and tetanus toxoid (TT) intradermally. First, the piercing ability of the ceramic (alumina) npMNAs, which contained over 100 microneedles per array, a length of 475 µm, and an average pore size of 80 nm, was evaluated in mouse skin. Then, the hydrodynamic diameters of DT and TT and the loading of DT, TT, and imiquimod into, and subsequent release from the npMNAs were assessed in vitro . It was shown that DT and TT were successfully loaded into the tips of the ceramic nanoporous microneedles, and by using near-infrared fluorescently labeled antigens, we found that DT and TT were released following piercing of the antigen-loaded npMNAs into ex vivo murine skin. Finally, the application of DT- and TT-loaded npMNAs onto mouse skin in vivo led to the induction of antigen-specific antibodies, with titers similar to those obtained upon subcutaneous immunization with a similar dose. In conclusion, we show for the first time, the potential of npMNAs for intradermal (ID) immunization with subunit vaccines, which opens possibilities for future ID vaccination designs.

Nanoporous Microneedle Arrays Effectively Induce Antibody Responses against Diphtheria and Tetanus Toxoid

Directory of Open Access Journals (Sweden)

Anne Marit de Groot

2017-12-01

Full Text Available The skin is immunologically very potent because of the high number of antigen-presenting cells in the dermis and epidermis, and is therefore considered to be very suitable for vaccination. However, the skin’s physical barrier, the stratum corneum, prevents foreign substances, including vaccines, from entering the skin. Microneedles, which are needle-like structures with dimensions in the micrometer range, form a relatively new approach to circumvent the stratum corneum, allowing for minimally invasive and pain-free vaccination. In this study, we tested ceramic nanoporous microneedle arrays (npMNAs, representing a novel microneedle-based drug delivery technology, for their ability to deliver the subunit vaccines diphtheria toxoid (DT and tetanus toxoid (TT intradermally. First, the piercing ability of the ceramic (alumina npMNAs, which contained over 100 microneedles per array, a length of 475 µm, and an average pore size of 80 nm, was evaluated in mouse skin. Then, the hydrodynamic diameters of DT and TT and the loading of DT, TT, and imiquimod into, and subsequent release from the npMNAs were assessed in vitro. It was shown that DT and TT were successfully loaded into the tips of the ceramic nanoporous microneedles, and by using near-infrared fluorescently labeled antigens, we found that DT and TT were released following piercing of the antigen-loaded npMNAs into ex vivo murine skin. Finally, the application of DT- and TT-loaded npMNAs onto mouse skin in vivo led to the induction of antigen-specific antibodies, with titers similar to those obtained upon subcutaneous immunization with a similar dose. In conclusion, we show for the first time, the potential of npMNAs for intradermal (ID immunization with subunit vaccines, which opens possibilities for future ID vaccination designs.

Active intestinal drug absorption and the solubility-permeability interplay.

Science.gov (United States)

Porat, Daniel; Dahan, Arik

2018-02-15

The solubility-permeability interplay deals with the question: what is the concomitant effect on the drug's apparent permeability when increasing the apparent solubility with a solubility-enabling formulation? The solubility and the permeability are closely related, exhibit certain interplay between them, and ongoing research throughout the past decade shows that treating the one irrespectively of the other may be insufficient. The aim of this article is to provide an overview of the current knowledge on the solubility-permeability interplay when using solubility-enabling formulations for oral lipophilic drugs, highlighting active permeability aspects. A solubility-enabling formulation may affect the permeability in opposite directions; the passive permeability may decrease as a result of the apparent solubility increase, according to the solubility-permeability tradeoff, but at the same time, certain components of the formulation may inhibit/saturate efflux transporters (when relevant), resulting in significant apparent permeability increase. In these cases, excipients with both solubilizing and e.g. P-gp inhibitory properties may lead to concomitant increase of both the solubility and the permeability. Intelligent development of such formulation will account for the simultaneous effects of the excipients' nature/concentrations on the two arms composing the overall permeability: the passive and the active arms. Overall, thorough mechanistic understanding of the various factors involved in the solubility-permeability interplay may allow developing better solubility-enabling formulations, thereby exploiting the advantages analyzed in this article, offering oral delivery solution even for BCS class IV drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Principal permeability determination from multiple horizontal well tests

Energy Technology Data Exchange (ETDEWEB)

Economides, M. [Texas A and M Univ., TX (United States); Munoz, A.; Ehlig-Economides, C.

1998-12-31

A method for obtaining principal permeability magnitudes and direction that requires only the linear flow regime from transient tests in three horizontal wells oriented in three distinct and arbitrary directions, is described. Well design optimization strategies require knowledge of both the principal permeability orientation as well as the horizontal permeability magnitudes. When the degree of horizontal permeability anisotropy (i.e. permeability in the bedding plane with respect to direction) is significant, the productivity of a long horizontal well will depend greatly on its direction, especially when the well is first brought into production. Productivities have been found to deviate substantially among wells in the same reservoir and this deviation has been attributed to differences in well orientation. In view of this fact, measuring permeability anisotropy becomes a compelling necessity. The success of the proposed method is illustrated by a case study in which the principal permeability magnitudes and direction from three wells were used to predict the productivity of a fourth well within 10 per cent. Use of the computed principal permeabilities from the case study, it was possible to forecast the cumulative production to show the significance of well trajectory optimization on the discounted cash flow and the net present value. 20 refs., 3 figs.

Permeability Tests on Eastern Scheldt Sand

DEFF Research Database (Denmark)

Jakobsen, Kim Parsberg

on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

Damage-induced permeability changes around underground excavations

International Nuclear Information System (INIS)

Coll, C.

2005-07-01

The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

Long-term Metal Performance of Three Permeable Pavements

Science.gov (United States)

EPA constructed a 4,000-m2 parking lot surfaced with three permeable pavements (permeable interlocking concrete pavers, pervious concrete, and porous asphalt) on the Edison Environmental Center in Edison, NJ in 2009. Samples from each permeable pavement infiltrate were collected...

Permeable Pavement Research - Edison, New Jersey

Science.gov (United States)

This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...

A methodology for extracting the electrical properties of human skin

International Nuclear Information System (INIS)

Birgersson, Ulrik; Nicander, Ingrid; Ollmar, Stig; Birgersson, Erik

2013-01-01

A methodology to determine dielectrical properties of human skin is presented and analyzed. In short, it is based on a mathematical model that considers the local transport of charge in the various layers of the skin, which is coupled with impedance measurements of both stripped and intact skin, an automated code generator, and an optimization algorithm. New resistivity and permittivity values for the stratum corneum soaked with physiological saline solution for 1 min and the viable skin beneath are obtained and expressed as easily accessible functions. The methodology can be extended to account for different electrode designs as well as more physical phenomena that are relevant to electrical impedance measurements of skin and their interpretation. (paper)

Effect of flexing and massage on in vivo human skin penetration and toxicity of zinc oxide nanoparticles.

Science.gov (United States)

Leite-Silva, Vânia R; Liu, David C; Sanchez, Washington Y; Studier, Hauke; Mohammed, Yousuf H; Holmes, Amy; Becker, Wolfgang; Grice, Jeffrey E; Benson, Heather Ae; Roberts, Michael S

2016-05-01

We assessed the effects of flexing and massage on human skin penetration and toxicity of topically applied coated and uncoated zinc oxide nanoparticles (˜75 nm) in vivo. Noninvasive multiphoton tomography with fluorescence lifetime imaging was used to evaluate the penetration of nanoparticles through the skin barrier and cellular apoptosis in the viable epidermis. All nanoparticles applied to skin with flexing and massage were retained in the stratum corneum or skin furrows. No significant penetration into the viable epidermis was seen and no cellular toxicity was detected. Exposure of normal in vivo human skin to these nanoparticles under common in-use conditions of flexing or massage is not associated with significant adverse events.

Transdermal microneedles for drug delivery applications

International Nuclear Information System (INIS)

Teo, Ai Ling; Shearwood, Christopher; Ng, Kian Chye; Lu Jia; Moochhala, Shabbir

2006-01-01

Transdermal drug delivery (TDD) has many advantages, the main one being the ability to maintain the prolonged release of drugs to attain optimal blood concentrations. Unfortunately, nature has provided a very effective protective barrier, the stratum corneum (sc), which limits TDD to certain types of drugs with specific properties. In order to enhance TDD, the idea of using microneedles to painlessly penetrate the sc barrier has previously been proposed. In this paper, we will review the different microneedles that are currently being developed as well as our own efforts in this area. Based on our experiences, we will offer our view on the key parameters for effective transdermal microneedle design as well as future directions in this area

Clinical Evaluation Of A New Emollient Cream In Cry Skin Conditions

Directory of Open Access Journals (Sweden)

Shukla V A

1998-01-01

Full Text Available Dry skin is a common problem both in healthy individuates and in patients with skin diseases. In all cases, emollients play important role in rehydrating the stratum corneum. To evaluate the efficacy of a new emollient, thirty-six patients with symptomatic dry skin disorders were enrolled. They were given the test emollient cream for topical application twice daily for 3 weeks and followed up weekly. Subjective complaints included pruritus and discomfort while objective parameters included scaling, erythema, roughness of skin, fissuring and hypopigmentation. Treatment with the test emollient cream reduced the severity in a majority of patients. Moreover, being free of perfume, co lour, urea and lanolin, the test cream was well tolerated by all participants.

Transdermal microneedles for drug delivery applications

Energy Technology Data Exchange (ETDEWEB)

Teo, Ai Ling [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117510 (Singapore); Shearwood, Christopher [School of Mechanical and Aerospace Engineering, 50 Nanyang Avenue, Singapore 639798 (Singapore); Ng, Kian Chye [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117510 (Singapore); Lu Jia [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117510 (Singapore); Moochhala, Shabbir [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117510 (Singapore)]. E-mail: mshabbir@dso.org.sg

2006-07-25

Transdermal drug delivery (TDD) has many advantages, the main one being the ability to maintain the prolonged release of drugs to attain optimal blood concentrations. Unfortunately, nature has provided a very effective protective barrier, the stratum corneum (sc), which limits TDD to certain types of drugs with specific properties. In order to enhance TDD, the idea of using microneedles to painlessly penetrate the sc barrier has previously been proposed. In this paper, we will review the different microneedles that are currently being developed as well as our own efforts in this area. Based on our experiences, we will offer our view on the key parameters for effective transdermal microneedle design as well as future directions in this area.

Optimization of Biopolymer Based Transdermal Films of Metoclopramide as an Alternative Delivery Approach

Directory of Open Access Journals (Sweden)

Betül Aktar

2014-05-01

Full Text Available The objectives of this study were to develop and to characterize sodium alginate based matrix-type transdermal films of metoclopramide hydrochloride (MTC in order to improve patient compliance to treatment. The suitability of sodium alginate was shown to be a natural film former in terms of the physicochemical, mechanical, and bioadhesive features of the MTC loaded transdermal films. Terpinolene provided the highest drug release among the different terpenes (nerolidol, eucalyptol, dl-limonene, or terpinolene assessed as enhancer. Attenuated Total Reflectance Infrared (ATR-FTIR spectroscopy analysis performed to evaluate the effect of the transdermal films on skin barrier confirmed enhancer induced lipid bilayer disruption in stratum corneum, indicating its permeation enhancement effect.

Assessment of penetration of quantum dots through in vitro and in vivo human skin using the human skin equivalent model and the tape stripping method

International Nuclear Information System (INIS)

Jeong, Sang Hoon; Kim, Jae Hwan; Yi, Sang Min; Lee, Jung Pyo; Kim, Jin Ho; Sohn, Kyung Hee; Park, Kui Lea; Kim, Meyoung-Kon; Son, Sang Wook

2010-01-01

Quantum dots (QDs) are rapidly emerging as an important class of nanoparticles (NPs) with potential applications in medicine. However, little is known about penetration of QDs through human skin. This study investigated skin penetration of QDs in both in vivo and in vitro human skin. Using the tape stripping method, this study demonstrates for the first time that QDs can actually penetrate through the stratum corneum (SC) of human skin. Transmission electron microscope (TEM) and energy diverse X-ray (EDX) analysis showed accumulation of QDs in the SC of a human skin equivalent model (HSEM) after dermal exposure to QDs. These findings suggest possible transdermal absorption of QDs after dermal exposure over a relatively long period of time.

Biophysical mechanisms of modification of skin optical properties in the UV wavelength range with nanoparticles

Science.gov (United States)

Popov, A. P.; Priezzhev, A. V.; Lademann, J.; Myllylä, R.

2009-05-01

In this paper, by means of the Mie theory and Monte Carlo simulations we investigate modification of optical properties of the superficial layer of human skin (stratum corneum) for 310- and 400-nm ultraviolet (UV) radiation by embedding of 35-200-nm-sized particles of titanium dioxide (TiO2) and silicon (Si). Problem of skin protection against UV light is of major importance due to increased frequency of skin cancer provoked by excessive doses of accepted UV radiation. For 310-nm light, the optimal sizes of the TiO2 and Si particles are found to be 62 and 55 nm, respectively, and for 400-nm radiation, 122 and 70 nm, respectively.

Biophysical mechanisms of modification of skin optical properties in the UV wavelength range with nanoparticles

International Nuclear Information System (INIS)

Popov, A. P.; Priezzhev, A. V.; Lademann, J.; Myllylae, R.

2009-01-01

In this paper, by means of the Mie theory and Monte Carlo simulations we investigate modification of optical properties of the superficial layer of human skin (stratum corneum) for 310- and 400-nm ultraviolet (UV) radiation by embedding of 35-200-nm-sized particles of titanium dioxide (TiO 2 ) and silicon (Si). Problem of skin protection against UV light is of major importance due to increased frequency of skin cancer provoked by excessive doses of accepted UV radiation. For 310-nm light, the optimal sizes of the TiO 2 and Si particles are found to be 62 and 55 nm, respectively, and for 400-nm radiation, 122 and 70 nm, respectively.

Permeability Barrier Generation in the Martian Lithosphere

Science.gov (United States)

Schools, Joe; Montési, Laurent

2015-11-01

Permeability barriers develop when a magma produced in the interior of a planet rises into the cooler lithosphere and crystallizes more rapidly than the lithosphere can deform (Sparks and Parmentier, 1991). Crystallization products may then clog the porous network in which melt is propagating, reducing the permeability to almost zero, i.e., forming a permeability barrier. Subsequent melts cannot cross the barrier. Permeability barriers have been useful to explain variations in crustal thickness at mid-ocean ridges on Earth (Magde et al., 1997; Hebert and Montési, 2011; Montési et al., 2011). We explore here under what conditions permeability barriers may form on Mars.We use the MELTS thermodynamic calculator (Ghiorso and Sack, 1995; Ghiorso et al., 2002; Asimow et al., 2004) in conjunction with estimated Martian mantle compositions (Morgan and Anders, 1979; Wänke and Dreibus, 1994; Lodders and Fegley, 1997; Sanloup et al., 1999; Taylor 2013) to model the formation of permeability barriers in the lithosphere of Mars. In order to represent potential past and present conditions of Mars, we vary the lithospheric thickness, mantle potential temperature (heat flux), oxygen fugacity, and water content.Our results show that permeability layers can develop in the thermal boundary layer of the simulated Martian lithosphere if the mantle potential temperature is higher than ~1500°C. The various Martian mantle compositions yield barriers in the same locations, under matching variable conditions. There is no significant difference in barrier location over the range of accepted Martian oxygen fugacity values. Water content is the most significant influence on barrier development as it reduces the temperature of crystallization, allowing melt to rise further into the lithosphere. Our lower temperature and thicker lithosphere model runs, which are likely the most similar to modern Mars, show no permeability barrier generation. Losing the possibility of having a permeability

Permeability of skin and oral mucosa to water and horseradish peroxidase as related to the thickness of the permeability barrier

International Nuclear Information System (INIS)

Squier, C.A.; Hall, B.K.

1985-01-01

The permeability of porcine skin and keratinized and nonkeratinized oral mucosa to tritium-labeled water and horseradish peroxidase (HRPO) was determined using perfusion chambers. Small blocks from each tissue were also incubated with HRPO and the extent of penetration visualized microscopically; this enabled measurements to be made of the thickness of the permeability barrier to this water-soluble tracer. Results obtained after inverting the oral mucosa in the chambers or adding metabolic inhibitors indicated that both compounds diffuse across the tissue. The permeability constants derived directly in the study showed that skin was less permeable than oral mucosa and that the floor of the mouth was significantly more permeable than all other regions. When these constants were normalized in terms of a standard permeability barrier thickness and the different tissues compared, the values obtained for skin were again less than those of the oral regions but, of these, the buccal mucosa was significantly higher. The difference in permeability between epidermis and keratinized oral epithelium may be due to differences in the volume density of membrane-coating granules known to exist between the tissues; differences between the oral mucosal regions may reflect differences in the nature of the intercellular barrier material

Update to Permeable Pavement Research at the Edison ...

Science.gov (United States)

The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavements including interlocking concrete permeable pavers, pervious concrete, and porous asphalt. The permeable pavements are limited to parking spaces while adjacent driving lanes are impermeable and drain to the permeable surfaces. The parking lot is instrumented for continuous monitoring with thermistors and water content reflectometers that measure moisture as infiltrate passes through the storage gallery beneath the permeable pavements into the underlying native soil. Each permeable surface of the parking lot has four lined sections that capture infiltrate in tanks for water quality analyses; these tanks are capable of holding volumes up to 4.1 m3, which represents up to 38 mm (1.5 in.) for direct rainfall on the porous pavement and runoff from adjacent driving lanes that drain into the permeable surface.Previous technical releases concerning the demonstration site focused on monitoring techniques, observed chloride and nutrient concentrations, surface hydrology, and infiltration and evaporation rates. This presentation summarizes these past findings and addresses current water quality efforts including pH, solids analysis, total organic carbon, and chemical oxygen demand. Stormwater runoff continues to be a major cause of water pollution in

Biostable glucose permeable polymer

DEFF Research Database (Denmark)

2017-01-01

A new biostable glucose permeable polymer has been developed which is useful, for example, in implantable glucose sensors. This biostable glucose permeable polymer has a number of advantageous characteristics and, for example, does not undergo hydrolytic cleavage and degradation, thereby providing...... a composition that facilitates long term sensor stability in vivo. The versatile characteristics of this polymer allow it to be used in a variety of contexts, for example to form the body of an implantable glucose sensor. The invention includes the polymer composition, sensor systems formed from this polymer...

Simplified Probabilistic Analysis of Settlement of Cyclically Loaded Soil Stratum by Point Estimate Method

Science.gov (United States)

Przewłócki, Jarosław; Górski, Jarosław; Świdziński, Waldemar

2016-12-01

The paper deals with the probabilistic analysis of the settlement of a non-cohesive soil layer subjected to cyclic loading. Originally, the settlement assessment is based on a deterministic compaction model, which requires integration of a set of differential equations. However, with the use of the Bessel functions, the settlement of a soil stratum can be calculated by a simplified algorithm. The compaction model parameters were determined for soil samples taken from subsoil near the Izmit Bay, Turkey. The computations were performed for various sets of random variables. The point estimate method was applied, and the results were verified by the Monte Carlo method. The outcome leads to a conclusion that can be useful in the prediction of soil settlement under seismic loading.

Transdermal Drug Delivery: Innovative Pharmaceutical Developments Based on Disruption of the Barrier Properties of the Stratum Corneum

Directory of Open Access Journals (Sweden)

Ahlam Zaid Alkilani

2015-10-01

Full Text Available The skin offers an accessible and convenient site for the administration of medications. To this end, the field of transdermal drug delivery, aimed at developing safe and efficacious means of delivering medications across the skin, has in the past and continues to garner much time and investment with the continuous advancement of new and innovative approaches. This review details the progress and current status of the transdermal drug delivery field and describes numerous pharmaceutical developments which have been employed to overcome limitations associated with skin delivery systems. Advantages and disadvantages of the various approaches are detailed, commercially marketed products are highlighted and particular attention is paid to the emerging field of microneedle technologies.

Transdermal Drug Delivery: Innovative Pharmaceutical Developments Based on Disruption of the Barrier Properties of the stratum corneum

Science.gov (United States)

Zaid Alkilani, Ahlam; McCrudden, Maelíosa T.C.; Donnelly, Ryan F.

2015-01-01

The skin offers an accessible and convenient site for the administration of medications. To this end, the field of transdermal drug delivery, aimed at developing safe and efficacious means of delivering medications across the skin, has in the past and continues to garner much time and investment with the continuous advancement of new and innovative approaches. This review details the progress and current status of the transdermal drug delivery field and describes numerous pharmaceutical developments which have been employed to overcome limitations associated with skin delivery systems. Advantages and disadvantages of the various approaches are detailed, commercially marketed products are highlighted and particular attention is paid to the emerging field of microneedle technologies. PMID:26506371

Changes in skin barrier during treatment with systemic alitretinoin: focus on skin susceptibility and stratum corneum ceramides

DEFF Research Database (Denmark)

Jungersted, Jakob Mutanu; Høgh, Julie Kaae; Hellgren, Lars

2010-01-01

) was performed on the volar forearm and evaluated by trans-epidermal water loss (TEWL), erythema, and a cyanoacrylate skin sample was obtained for lipid analysis. We found no significant changes in response to SLS irritation as evaluated by TEWL and erythema, after treatment with alitretinoin for 2 months...

Changes in skin barrier during treatment with systemic alitretinoin: focus on skin susceptibility and stratum corneum ceramides

DEFF Research Database (Denmark)

Jungersted, J.M.; Høgh, Julie Kaae; Hellgren, Lars

2010-01-01

) was performed on the volar forearm and evaluated by trans-epidermal water loss (TEWL), erythema, and a cyanoacrylate skin sample was obtained for lipid analysis. We found no significant changes in response to SLS irritation as evaluated by TEWL and erythema, after treatment with alitretinoin for 2 months......Alitretinoin is a new drug for systemic treatment of chronic hand eczema. Previous functional tests of skin topically treated with retinoids have indicated impaired skin barrier function, but no data are available on barrier parameters after systemic alitretinoin treatment. To investigate...

Electroporation of Skin Stratum Corneum Lipid Bilayer and Molecular Mechanism of Drug Transport: A Molecular Dynamics Study.

Science.gov (United States)

Gupta, Rakesh; Rai, Beena

2018-04-30

Skin electroporation has been used significantly to increase the drug permeation. However, molecular mechanism, which resulted in enhancement of flux through skin, is still not known. In this study, extensive atomistic molecular dynamics simulation of skin lipids (made up of ceramide (CER), cholesterol (CHOL) and free fatty acid (FFA)) have been performed at various external electric field. We show for the first time the pore formation in the skin lipid bilayer during the electroporation. We show the effect of applied external electrical field on the pore formation dynamics in lipid bilayer of different size and composition. The pore formation and resealing kinetics were different and was found to be highly dependent on the composition of skin lipid bilayer. The pore formation time decreased with increase in the bilayer size. The pore sustaining electric field was found to be in the range of 0.20-0.25 V/nm for equimolar CER, CHOL and FFA lipid bilayer. The skin lipid bilayer (1:1:1), sealed itself within 20 ns after the removal of external electric field. We also present the molecular mechanism of enhancement of drug permeation in the presence of external field as compared to the passive diffusion. The molecular level understanding obtained here could help in optimizing/designing the electroporation experiments for effective drug delivery. For a given skin composition and size of drug molecule, the combination of pore formation time and pore growth model can be used to know aproiri the desired electric field and time for application of electric field.

Soils - Mean Permeability

Data.gov (United States)

Kansas Data Access and Support Center — This digital spatial data set provides information on the magnitude and spatial pattern of depth-weighted, mean soil permeability throughout the State of Kansas. The...

Effect of aggregate grain size distribution on properties of permeable ...

African Journals Online (AJOL)

) ratio on the mechanical properties of permeable concrete is investigated. The aim of this study is to prepare permeable concrete mixture with optimum properties in terms of strength and permeability. For this purpose, five different permeable ...