Structure–Permeability Relationship Analysis of the Permeation Barrier Properties of the Stratum Corneum and Viable Epidermis/Dermis of Rat Skin

2008 ◽  
Vol 97 (10) ◽  
pp. 4391-4403 ◽  
Author(s):  
Koji Yamaguchi ◽  
Tetsuya Mitsui ◽  
Yoshinori Aso ◽  
Kenji Sugibayashi
Author(s):  
R. R. Warner

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.


2020 ◽  
Vol 15 (3) ◽  
pp. 1934578X1990068
Author(s):  
Noriyuki Uchida ◽  
Masayoshi Yanagi ◽  
Hiroki Hamada

Composite nanoparticles composed of an anionic phospholipid of 1,2-dipalmitoyl-sn-glycero-3-phosphorylglycerol (DPPG) and paclitaxel (PTX) were successfully prepared by mixing them in water followed by a subsequent heating/cooling process. The size of DPPG-PTX nanoparticle could be easily tuned by ultrasonic fragmentation. Upon addition of small-sized fluorescently labeled paclitaxel (FLPTX) nanoparticles with DPPG (DPPG-FLPTX) to rat skin tissue, part of the FLPTX molecules permeated to the stratum corneum.


2021 ◽  
pp. 1-13
Author(s):  
Philip W. Wertz

Cornified cells of the stratum corneum have a monolayer of an unusual lipid covalently attached to the outer surface. This is referred to as the corneocyte lipid envelope (CLE). It consists of a monolayer of ω-hydroxyceramides covalently attached to the outer surface of the cornified envelope. The CLE is essential for proper barrier function of the skin and is derived from linoleate-rich acylglucosylceramides synthesized in the viable epidermis. Biosynthesis of acylglucosylceramide and its conversion to the cornified envelope is complex. Acylglucosylceramide in the bounding membrane of the lamellar granule is the precursor of the CLE. The acylglucosylceramide in the limiting membrane of the lamellar granule may be oriented with the glucosyl moiety on the inside. Conversion of the acylglucosylceramide to the CLE requires removal of the glucose by action of a glucocerebrosidase. The ester-linked fatty acid may be removed by an as yet unidentified esterase, and the resulting ω-hydroxyceramide may become ester linked to the outer surface of the cornified envelope through action of transglutaminase 1. Prior to removal of ester-linked fatty acids, linoleate is oxidized to an epoxy alcohol through action of 2 lipoxygenases. This can be further oxidized to an epoxy-enone, which can spontaneously attach to the cornified envelope through Schiff’s base formation. Mutations of genes coding for enzymes involved in biosynthesis of the CLE result in ichthyosis, often accompanied by neurologic dysfunction. The CLE is recognized as essential for barrier function of skin, but many questions about details of this essentiality remain. What are the relative roles of the 2 mechanisms of lipid attachment? What is the orientation of acylglucosylceramide in the bounding membrane of lamellar granules? Some evidence supports a role for CLE as a scaffold upon which intercellular lamellae unfold, but other evidence does not support this role. There is also controversial evidence for a role in stratum corneum cohesion. Evidence is presented to suggest that covalently bound ω-hydroxyceramides serve as a reservoir for free sphingosine that can serve in communicating with the viable epidermis and act as a potent broad-acting antimicrobial at the skin surface. Many questions remain.


Cosmetics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 64
Author(s):  
Pavel Mokrejš ◽  
Jana Pavlačková ◽  
Dagmar Janáčová ◽  
Matouš Huťťa

Although keratin hydrolysates (KH) are added to skin care agents, detailed studies on the moisturising effects of KH are lacking. The aim of this study is to test whether adding KH into an ointment base (OB) heighten hydration of the skin and diminish transepidermal loss of water (TEWL). Formulations containing 2%, 4%, and 6% of KH (based on OB weight) were prepared. Hydration, TEWL and skin pH were measured; intervals of measurements were as follows: 1, 2, 3, 4, 24 and 48 h. Testing was carried out on 10 men. In terms of hydration, supplementing the OB with 2% KH is optimal, as an 11–19% increase occurs in hydration of stratum corneum (SC). All the formulations with added KH as tested caused TEWL to decline after application. Keratin hydrolysate makes for an excellent occlusive; adding it to OB results in a 30–50% reduction in TEWL after application. KH functions as a humectant as well, as it helps to bind water from the lower layers of the epidermis to the SC. Formulations with additions of 2–6% of KH were stable in structure and did not cause phase separation even after 6 months storage.


1999 ◽  
Vol 113 (5) ◽  
pp. 821-829 ◽  
Author(s):  
Stephan El Gammal ◽  
Claudia El Gammal ◽  
Katharina Kaspar ◽  
Carsten Pieck ◽  
Peter Altmeyer ◽  
...  

2020 ◽  
Vol 15 (5) ◽  
pp. 1934578X2092557
Author(s):  
Noriyuki Uchida ◽  
Masayoshi Yanagi ◽  
Hiroki Hamada

Piceid, stilbenoid glucoside, is a representative resveratrol derivative. Because of a high tyrosinase inhibitory activity of piceid through resveratrol derivatives, transdermal delivery of piceid has been desired for taking advantage of the activity. Here we successfully prepared composite nanoparticles composed of anionic phospholipid of 1,2-dipalmitoyl- sn-glycero-3-phosphorylglycerol (DPPG) and piceid by mixing them in water and a subsequent heating/cooling process. When small-sized fluorescently labeled DPPG-piceid (DPPG-FLpiceid) nanoparticles were added to rat skin tissue, FLpiceid molecules were localized in stratum corneum.


1998 ◽  
Vol 9 (1) ◽  
pp. 65
Author(s):  
Ludger Kolbe ◽  
Tracy Stoudemayer ◽  
Albert M. Kligman

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