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.

This study used neutron diffraction to investigate a ceramide-[NP] C24/[AP] C24 /[EOS]-br C30/cholesterol/lignoceric acid (0.6: 0.3: 0.

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].

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.

Influence of a Novel Dimeric Ceramide Molecule on the Nanostructure and Thermotropic Phase Behavior of a Stratum Corneum Model Mixture.

The stratum corneum (SC) is the outermost layer of the skin and is composed of a multilayered assembly of mostly ceramids (Cer), free fatty acids, cholesterol (Chol), and cholesterol sulfate (Chol-S). Because of the tight packing of these lipids, the SC features unique barrier properties defending the skin from environmental influences. Under pathological conditions, where the skin barrier function is compromised, topical application of molecules that rigidify the SC may lead to a restored barrier function.

Synthesis of specific deuterated derivatives of the long chained stratum corneum lipids [EOS] and [EOP] and characterization using neutron scattering.

The synthesis of specific deuterated derivatives of the long chained ceramides [EOS] and [EOP] is described. The structural differences with respect to the natural compounds are founded in the substitution of the 2 double bonds containing linoleic acid by a palmitic acid branched with a methyl group in 10-position. The specific deuteration is introduced both in the branched and in the terminal methyl group, which was realized by common methods of successive deuteration of carboxylic groups in 3 steps.

Phase separation in ceramide[NP] containing lipid model membranes: neutron diffraction and solid-state NMR.

The stratum corneum is the outermost layer of the skin and protects the organism against external influences as well as water loss. It consists of corneocytes embedded in a mixture of ceramides, fatty acids, and cholesterol in a molar ratio of roughly 1 : 1 : 1. The unique structural and compositional arrangement of these stratum corneum lipids is responsible for the skin barrier properties.

Synthesis of specifically deuterated ceramide [AP]-C18 and its biophysical characterization using neutron diffraction.

The very heterogeneous group of ceramides is known to be mandatory for proper barrier functions of the outermost layer of mammalian skin, referred to as stratum corneum (SC). The synthesis of a specifically deuterated ceramide [AP]-C18 variant is described. The synthesized ceramide contains the racemic forms of the α hydroxy fatty acid.

Influence of the penetration enhancer isopropyl myristate on stratum corneum lipid model membranes revealed by neutron diffraction and H NMR experiments.

The stratum corneum (SC) provides the main barrier properties in native skin. The barrier function is attributed to the intercellular lipids, forming continuous multilamellar membranes. In this study, SC lipid membranes in model ratios were enriched with deuterated lipids in order to investigate structural and dynamical properties by neutron diffraction and H solid-state NMR spectroscopy.

Synthesis of ceramides NS and NP with perdeuterated and specifically ω deuterated N-acyl residues.

The synthesis of 12 deuterated ceramides with either a deuteration at the last carbon atom of the amide bound fatty acid or a perdeuterated fatty acid chain is described. The ceramides were prepared starting from sphingosine or phytosphingosine and ω deuterated or perdeuterated fatty acids with PyBOP® as activating agent in high yields. For the synthesis of the specifically deuterated fatty acids, dicarboxylic acids were transformed into ω deuterated alkyl bromide, which was chain elongated with blocked ω bromo alcohols by copper catalyzed Grignard coupling.

Localization of methyl-branched ceramide [EOS] species within the long-periodicity phase in stratum corneum lipid model membranes: A neutron diffraction study.

The outermost layer of the mammalian skin, the stratum corneum (SC), is a very thin structure and realizes simultaneously the main barrier properties. The penetration barrier for xenobiotica is mostly represented by a complex lipid matrix. There is great interest in the subject of getting information about the arrangement of the lipids, which are mainly ceramides (CER), free fatty acids (FFA) and cholesterol (CHOL).

Controlled Penetration of a Novel Dimeric Ceramide into and across the Stratum Corneum Using Microemulsions and Various Types of Semisolid Formulations.

Ceramides (CERs) are integral parts of the intercellular lipid lamellae of the stratum corneum (SC), which is responsible for the barrier function of the skin. Many skin diseases such as atopic dermatitis and psoriasis are associated with the depletion or disturbance of the level of CERs in the SC. Administration of an exogenous novel dimeric ceramide (dCER) deep into the SC may help to stabilize the SC barrier substantially and to treat some skin disease conditions.