Enhanced optical clearing of human skin at topical application of immersion agents to stratum corneum pretreated by a lattice-like photothermal ablation

2006 ◽  
Author(s):  
Valery V. Tuchin ◽  
Gregory B. Altshuler ◽  
Anna A. Gavrilova ◽  
Alexander B. Pravdin ◽  
David Tabatadze ◽  
...  
Keyword(s):  
Stratum Corneum ◽  
Human Skin ◽  
Topical Application ◽  
Optical Clearing ◽  
Photothermal Ablation

Mechanisms of in vivo optical clearing of human skin at application of glycerol and lattice-like photothermal damage of stratum corneum

2006 ◽  
Author(s):  
Anna A. Gavrilova ◽  
Alexander B. Pravdin ◽  
Elena A. Zubkova ◽  
Valery V. Tuchin ◽  
Gregory B. Altshuler ◽  
...  
Keyword(s):  
Stratum Corneum ◽  
Human Skin ◽  
Optical Clearing

Changes in corneocyte element concentrations occur in skin inner stratum corneum

1990 ◽  
Vol 48 (2) ◽  
pp. 146-147
Author(s):  
R. R. Warner
Keyword(s):  
Stratum Corneum ◽  
Human Skin ◽  
Element Concentration ◽  
Skin Barrier ◽  
Barrier Properties ◽  
Brick Wall ◽  
Inorganic Elements ◽  
Dry Skin ◽  
Skin Biopsies ◽  
Intercellular Lipid

Keratinocytes undergo maturation during their transit through the viable layers of skin, and then abruptly transform into flattened, anuclear corneocytes that constitute the cellular component of the skin barrier, the stratum corneum (SC). The SC is generally considered to be homogeneous in its structure and barrier properties, and is often shown schematically as a featureless brick wall, the “bricks” being the corneocytes, the “mortar” being intercellular lipid. Previously we showed the outer SC was not homogeneous in its composition, but contained steep gradients of the physiological inorganic elements Na, K and Cl, likely originating from sweat salts. Here we show the innermost corneocytes in human skin are also heterogeneous in composition, undergoing systematic changes in intracellular element concentration during transit into the interior of the SC.Human skin biopsies were taken from the lower leg of individuals with both “good” and “dry” skin and plunge-frozen in a stirred, cooled isopentane/propane mixture.

scholarly journals Impact of optical clearing on ex vivo human skin optical properties characterized by spatially resolved multimodal spectroscopy

2021 ◽  
Author(s):  
Sergey M. Zaytsev ◽  
Marine Amouroux ◽  
Grégoire Khairallah ◽  
Alexey N. Bashkatov ◽  
Valery V. Tuchin ◽  
...  
Keyword(s):  
Optical Properties ◽  
Human Skin ◽  
Ex Vivo ◽  
Optical Clearing ◽  
Spatially Resolved

Human Skin Binding and Absorption of Contaminants from Ground and Surface Water During Swimming and Bathing

1989 ◽  
Vol 8 (5) ◽  
pp. 853-859 ◽  
Author(s):  
Ronald C. Wester ◽  
Howard I. Maibach
Keyword(s):  
Surface Water ◽  
Stratum Corneum ◽  
Human Skin ◽  
The Body ◽  
Water Soluble ◽  
Exposure Effect ◽  
Human Stratum Corneum ◽  
Water Dilution

Contaminants exist in ground and surface water. Human skin has the capacity to bind and then absorb these contaminants into the body during swimming and bathing. Powdered human stratum corneum will bind both lipid-soluble (alachlor, polychlorinated biphenyls [PCBs], benzene) and water-soluble (nitroaniline) chemicals. In vitro (human skin) and in vivo (Rhesus monkey) studies show that these chemicals readily distribute into skin, and then some of the chemical is absorbed into the body. Linearity in binding and absorption exists for nitroaniline over a 10-fold concentration range. Multiple exposure to benzene is at least cumulative. Binding and absorption can be significant for exposures as short as 30 min, and will increase with time. Absorption with water dilution increased for alachlor, but not for dinoseb. Soap reversed the partitioning of alachlor between human stratum corneum and water. The PCBs could be removed from skin by soap and water (70% efficiency) for up to 3 h and then decontamination potential decreased, due to continuing skin absorption. The model in vitro and in vivo systems used should permit easy estimation of this area of extensive human exposure effect on risk assessment.

scholarly journals Enhanced Transdermal Delivery of Pranoprofen Using a Thermo-Reversible Hydrogel Loaded with Lipid Nanocarriers for the Treatment of Local Inflammation

2021 ◽  
Vol 15 (1) ◽  
pp. 22
Author(s):  
María Rincón ◽  
Marcelle Silva-Abreu ◽  
Lupe Carolina Espinoza ◽  
Lilian Sosa ◽  
Ana Cristina Calpena ◽  
...  
Keyword(s):  
Human Skin ◽  
Topical Application ◽  
Topical Treatment ◽  
Transdermal Delivery ◽  
Ex Vivo ◽  
Skin Permeation ◽  
In Vitro Release ◽  
Heterogeneous Structure ◽  
Clinical Environment ◽  
Local Skin

A biocompatible topical thermo-reversible hydrogel containing Pranoprofen (PF)-loaded nanostructured lipid carriers (NLCs) was studied as an innovative strategy for the topical treatment of skin inflammatory diseases. The PF-NLCs-F127 hydrogel was characterized physiochemically and short-time stability tests were carried out over 60 days. In vitro release and ex vivo human skin permeation studies were carried out in Franz diffusion cells. In addition, a cytotoxicity assay was studied using the HaCat cell line and in vivo tolerance study was performed in humans by evaluating the biomechanical properties. The anti-inflammatory effect of the PF-NLCs-F127 was evaluated in adult male Sprague Daw-ley® rats using a model of inflammation induced by the topical application of xylol for 1 h. The developed PF-NLCs-F127 exhibited a heterogeneous structure with spherical PF-NLCs in the hydrogel. Furthermore, a thermo-reversible behaviour was determined with a gelling temperature of 32.5 °C, being close to human cutaneous temperature and thus favouring the retention of PF. Furthermore, in the ex vivo study, the amount of PF retained and detected in human skin was high and no systemic effects were observed. The hydrogel was found to be non-cytotoxic, showing cell viability of around 95%. The PF-NLCs-F127 is shown to be well tolerated and no signs of irritancy or alterations of the skin’s biophysical properties were detected. The topical application of PF-NLCs-F127 hydrogel was shown to be efficient in an inflammatory animal model, preventing the loss of stratum corneum and reducing the presence of leukocyte infiltration. The results from this study confirm that the developed hydrogel is a suitable drug delivery carrier for the transdermal delivery of PF, improving its dermal retention, opening the possibility of using it as a promising candidate and safer alternative to topical treatment for local skin inflammation and indicating that it could be useful in the clinical environment.

scholarly journals Development of Artificial Skin Using Keratin Film for Evaluation of Puncture Performance of Microneedle

2020 ◽  
Vol 32 (2) ◽  
pp. 351-361
Author(s):  
Ryo Nishino ◽  
Seiji Aoyagi ◽  
Masato Suzuki ◽  
Atsushi Ueda ◽  
Yuki Okumura ◽  
...  
Keyword(s):  
Stratum Corneum ◽  
Human Skin ◽  
Human Hair ◽  
Subcutaneous Tissue ◽  
Artificial Skin ◽  
Resistance Force ◽  
Stick Slip ◽  
Silicon Rubber ◽  
Animal Skin ◽  
Slip Phenomenon

Humans do not feel pain when bitten by mosquitos; therefore, we have attempted to develop a microneedle that mimics the puncturing mechanism of mosquitos. We have quantitatively evaluated the puncturing performance of the developed microneedle by puncturing an artificial skin made from polydimethylsiloxane (PDMS), a kind of silicon rubber. Unlike the mono-layered PDMS, however, animal skin including human skin is structured to have a hard stratum corneum, epidermis and dermis over soft subcutaneous tissue. In this paper, we propose an artificial skin having a two-layered hard/soft structure, constructed from PDMS with a human-hair-derived keratin film adhered onto the top surface. We evaluated the hardness of the keratin film (Young’s modulus) and found that it could qualitatively simulate the hard layers of the skin including the stratum corneum. The artificial skin we developed reproduced the following phenomena: the decrease in resistance force of animal skin at the point when the needle penetrates the surface followed by variation in resistance due to the stick-slip phenomenon as the needle penetrates more deeply.

scholarly journals Optical Clearing of Human Skin Using Polyethylene Glycols

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Kirill V. Berezin ◽  
Konstantin N. Dvoretskiy ◽  
Vladimir V. Nechaev ◽  
Anatoliy M. Likhter ◽  
Ilmira T. Shagautdinova ◽  
...  
Keyword(s):  
Human Skin ◽  
Polyethylene Glycols ◽  
Optical Clearing

scholarly journals Interaction between SARS-CoV-2 spike glycoprotein and human skin models: a molecular dynamics study

2021 ◽  
Author(s):  
Marc Domingo ◽  
Jordi Faraudo
Keyword(s):  
Stratum Corneum ◽  
Human Skin ◽  
Skin Surface ◽  
Viral Envelope ◽  
Solid Surfaces ◽  
Spike Glycoprotein ◽  
Indirect Transmission ◽  
Physico Chemical ◽  
Human Skin Models ◽  
Structure Orientation

The possibility of contamination of human skin by infectious virions plays an important role in indirect transmission of respiratory viruses but little is known about the fundamental physico-chemical aspects of the virus-skin interactions. In the case of coronaviruses, the interaction with surfaces (including the skin surface) is mediated by their large glycoprotein spikes that protrude from (and cover) the viral envelope. Here, we perform all atomic simulations between the SARS-CoV-2 spike glycoprotein and human skin models. We consider an "oily" skin covered by sebum and a "clean" skin exposing the stratum corneum. The simulations show that the spike tries to maximize the contacts with stratum corneum lipids, particularly ceramides, with substantial hydrogen bonding. In the case of "oily" skin, the spike is able to retain its structure, orientation and hydration over sebum with little interaction with sebum components. Comparison of these results with our previous simulations of the interaction of SARS-CoV-2 spike with hydrophilic and hydrophobic solid surfaces, suggests that the"soft" or "hard" nature of the surface plays an essential role in the interaction of the spike protein with materials.

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