Stratum corneum lipid organization

M. W. de Jager, G. S. Gooris, I. P. Dolbnya, W. Bras, M. Ponec, and J. A. Bouwstra. Novel lipid mixtures based on synthetic ceramides reproduce the unique stratum corneum lipid organization. J. Lipid Res. 45 923-932 (2004). 

The above results demonstrate that the unique stratum corneum lipid organization can be reproduced in vitro with mixtures based on cholesterol, free fatty acids, and a limited number of synthetic ceramides. The results further reveal that the formation of the LPP is rather insensitive toward changes in the total composition of cholesterol, CER, and free fatty acids over a wide range of molar ratios. This is in excellent agreement with the in vivo situation, in which a high interindividual variability in stratum corneum lipid composition usually does not lead to substantial changes in the lipid organization. 

Pilgram, G.S.K., et al. 1999. Electron diffraction provides new information on human stratum corneum lipid organization studied in relation to depth and temperature. J Invest Dermatol 113 403. 

Lavrijsen, A.P.M., et al. 1995. Reduced skin barrier function parallels abnormal stratum corneum lipid organization in patients with lamellar ichthyosis. J Invest Dermatol 105 619. 

Bouwstra, J.A., et al. 1999. Cholesterol sulfate and calcium affect stratum corneum lipid organization over a wide temperature range. J Lipid Res 40 2303. 

Bouwstra, J.A. et al., pH, cholesterol sulfate, and fatty acids affect the stratum corneum lipid organization, J. Invest. Dermatol. Symp. Proc., 3, 69, 1998. 

The physical state and molecular organization of the stratum corneum intercellular lipid matrix largely determines the hydration-level of the stratum corneum and thus, indirectly, the mechanical properties and appearance of the skin. A better understanding of stratum corneum lipid organization may thus aid the development of more efficient cosmetic formulations. 

In the first part of this chapter, the formation and structure of the stratum corneum will be discussed. The second part describes the composition and organization of the intercellular stratum corneum lipids in vivo and in vitro. 

To better understand the structure, function, and dynamics of the endogenous lipid matrix of the stratum corneum intercellular space some general principles of lipid phase behavior, dynamics, and structural organization may represent a useful starting point. Further follows a short overview of some basic physico-chemical principles that may be of relevance for stratum corneum lipid research, followed by a presentation of the new technique cryo-transmission electron microscopy of fully hydrated vitreous skin sections and how this technique recently has been applied to the study of the structural organization and formation of the lipid matrix of the stratum corneum intercellular space. 

The barrier function of skin is attributed predominantly to its outermost layer, the stratum corneum, which protects the body from a percutaneous penetration of compounds and from desiccation, thus permitting terrestrial mammals to control their internal aqueous balance and to survive in a nonaqueous environment. Stratum corneum lipids have highly specific composition and organization and play an important role in the skin... 

The Lipid Organization in Stratum Corneum and Model Systems Based on Ceramides... 

Altered Lipid Composition and Organization in Stratum Corneum of Diseased and Dry Skin... 

All the above-mentioned changes in lipid composition and organization in diseased and dry skin likely contribute to an impaired stratum corneum barrier function and increased susceptibility to dry skin. However, as previously indicated, abnormalities in the process of envelope formation may also strongly influence the stratum corneum barrier integrity. Therefore, more information is required to elucidate the precise mechanisms by which stratum corneum structure and function are altered. 

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