Influence of cholesterol on the structure of stratum corneum lipid model membrane

Abstract

a b s t r a c tThis study describes the influence of cholesterol on a model membrane consisting of four stratum corneum (SC) lipids in three different states at 32 and 85 • C. Using small-angle X-ray diffraction on multilamellar vesicles, the lamellar repeat distance, D, was determined. Small-angle neutron scattering on unilamellar vesicles was used to calculate the membrane thickness, average area of the membrane surface per molecule, average volume per molecule in the membrane, and membrane density. After the sample preparation, the membranes show one lamellar phase. Over 10 days, the systems separate into two lamellar phases and crystalline cholesterol. On heating the samples to 85 • C, the domains merge into one phase, the D-value of which increases slightly with increasing cholesterol concentration. On cooling the samples back to 32 • C, only one phase is observable again. The increasing cholesterol concentration in the membrane causes a decrease in the D-value, membrane thickness, and membrane density. Simultaneously, the area of the membrane surface and membrane volume per molecule increase. In conclusion, cholesterol fluidises the SC lipid membranes in the state below the main phase transition and condenses above it. This effect can have an important impact on the pathologic skin states such as the recessive X-linked ichthyosis.

Phase behavior of skin lipid mixtures: the effect of cholesterol on lipid organization

“…32,33 There are not many studies published aiming to investigate the effect of CHOL on the SC lipid organization systematically. 34 A few studies report on the phase behavior of CER containing lipid mixtures including CHOL. 34,35 These studies reveal that CHOL controls the miscibility of the CER containing lipid mixtures.…”

“…34 A few studies report on the phase behavior of CER containing lipid mixtures including CHOL. 34,35 These studies reveal that CHOL controls the miscibility of the CER containing lipid mixtures. In previous studies, the phase behavior of lipid mixtures prepared from isolated human CERs or pig CERs in the presence of varying levels of CHOL has been investigated.…”

In vivo confocal Raman spectroscopy and molecular dynamics analysis of penetration of retinyl acetate into stratum corneum

“…The fatty acid is significantly more mobile than the ceramide [9]. The role of the cholesterol allows fluidity for the lipid bilayer [37], and the cholesterol sulfate facilitates and stabilizes the formation of the lipid lamellae [38].…”

Effect of composition on water permeability of model stratum corneum lipidmembranes

“…[9][10][11] Despite the potential importance of the effect of composition on the permeability of the SC lipid membranes, majority of studies in this area have focused on the characterization of structural changes in the lipid membranes induced by different compositional changes. 4,7,8,[12][13][14][15][16][17] For example, using neutron diffraction, long-chained saturated fatty acids were observed to form a separate fatty-acid-rich phase in the SC lipid membrane. 13 Studies based on spectroscopy have shown that the presence of unsaturated fatty acids within the SC lipid membrane perturbs the crystalline structure and enhances the fluidity of the lipid membrane.…”