Self-Assembly of Coarse-Grained Stratum Corneum Lipids

The top layer of the skin, known as the stratum corneum, acts as a barrier to foreign agents entering the body and to water leaving the body. Experimentally, while it is known that the lipids of the stratum cornenum are organized in lamellar bilayer structures in which the lipid chains are highly ordered, a detailed picture of the molecular organization of the lipids has not been elucidated. To help understand the molecular level arrangement of the skin lipids both atomistically detailed and coarse-grained molecular models for the three main classes of lipid found in the SC (ceramides, free fatty acids and cholesterol) have been developed for use in molecular dynamics simulations. Coarse-grained models allow molecular simulations to be performed on larger spatial and temporal scales than is possible through atomistic simulation alone and are necessary to study self-assembly in mixed lipid systems. Results will be presented for a number of pure and mixed lipid systems to demonstrate the suitability of the proposed models for describing crystalline and melt lipid phases and future work on studying the complex lipid mixtures seen in the SC will be discussed.