The physics of stratum corneum lipid membranes.
The stratum corneum (SC), the outermost layer of skin, comprises rigid corneocytes (keratin-filled dead cells) in a specialized lipid matrix. The continuous lipid matrix provides the main barrier against uncontrolled water loss and invasion of external pathogens. Unlike all other biological lipid membranes (such as intracellular organelles and plasma membranes), molecules in the SC lipid matrix show small hydrophilic groups and large variability in the length of the alkyl tails and in the numbers and positions of groups that are capable of forming hydrogen bonds. Molecular simulations provide a route for systematically probing the effects of each of these differences separately. In this article, we present the results from atomistic molecular dynamics of selected lipid bilayers and multi-layers to probe the effect of these polydispersities. We address the nature of the tail packing in the gel-like phase, the hydrogen bond network among head groups, the bending moduli expected for leaflets comprising SC lipids and the conformation of very long ceramide lipids in multi-bilayer lipid assemblies.This article is part of the themed issue 'Soft interfacial materials: from fundamentals to formulation'.
School of Mathematics, University of Leeds, Leeds LS2 9JT, UK.
Chinmay
C
Das
Department of Physics and Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057, USA peter.olmsted@georgetown.edu.
Peter D
http://orcid.org/0000-0001-6538-9385
PD
Olmsted
D002462:Cell Membrane / Q000737:chemistry* / Q000502:physiology*; D004817:Epidermis / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry*; D056004:Molecular Dynamics Simulation
D008051:Lipid Bilayers
computer simulations; lipid bilayers; liquid crystallinity; molecular dynamics; phase transitions; skin lipids