Biomaterial Database

Stratum corneum lipid phase transitions and water barrier properties. 1987

G M Golden, and D B Guzek, and A H Kennedy, and J E McKie, and R O Potts

In mammals, the outer skin layer, the stratum corneum, is the ultimate barrier to water loss. In order to relate barrier function to stratum corneum structure, samples from porcine skin were investigated by using differential scanning calorimetry (DSC), infrared (IR) spectroscopy, and water permeability techniques. Results of DSC and IR studies show that stratum corneum lipids undergo thermal transitions between 60 and 80 degrees C similar to lipid thermotropic transitions seen in a variety of synthetic and biological membranes. Results of water flux experiments performed under conditions similar to those of the DSC and IR studies show an abrupt change in permeability at about 70 degrees C. At low temperatures, water flux values are similar to those obtained for human skin in vivo, yielding an activation energy of 17 kcal/mol, in excellent agreement with values obtained for water flux through a variety of lipid biomembranes. In contrast, at temperatures above about 70 degrees C, water flux is characterized by an activation energy only slightly higher than that of free diffusion, suggesting that the stratum corneum offers little diffusional resistance under these conditions. These combined results suggest that increased disorder in stratum corneum lipid structure, brought about by thermotropic transitions, results in dramatically altered diffusional resistance of this tissue to water flux. Thus, as found for numerous biological membranes, water flux and lipid order in porcine stratum corneum are inversely related.

UI	MeSH Term	Description	Entries
D008563	Membrane Lipids	Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.	Cell Membrane Lipid,Cell Membrane Lipids,Membrane Lipid,Lipid, Cell Membrane,Lipid, Membrane,Lipids, Cell Membrane,Lipids, Membrane,Membrane Lipid, Cell,Membrane Lipids, Cell
D010539	Permeability	Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.	Permeabilities
D002152	Calorimetry, Differential Scanning	Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.	Differential Thermal Analysis, Calorimetric,Calorimetric Differential Thermal Analysis,Differential Scanning Calorimetry,Scanning Calorimetry, Differential
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012869	Skin Absorption	Uptake of substances through the SKIN.	Absorption, Skin,Intracutaneous Absorption,Intradermal Absorption,Percutaneous Absorption,Transcutaneous Absorption,Transdermal Absorption,Absorption, Intracutaneous,Absorption, Intradermal,Absorption, Percutaneous,Absorption, Transcutaneous,Absorption, Transdermal,Absorptions, Intracutaneous,Absorptions, Intradermal,Absorptions, Percutaneous,Absorptions, Skin,Absorptions, Transcutaneous,Absorptions, Transdermal,Intracutaneous Absorptions,Intradermal Absorptions,Percutaneous Absorptions,Skin Absorptions,Transcutaneous Absorptions,Transdermal Absorptions
D012879	Skin Physiological Phenomena	The functions of the skin in the human and animal body. It includes the pigmentation of the skin.	Skin Physiological Processes,Skin Physiology,Physiology, Skin,Skin Physiological Concepts,Skin Physiological Phenomenon,Skin Physiological Process,Concept, Skin Physiological,Concepts, Skin Physiological,Phenomena, Skin Physiological,Phenomenas, Skin Physiological,Phenomenon, Skin Physiological,Phenomenons, Skin Physiological,Physiological Concept, Skin,Physiological Concepts, Skin,Physiological Phenomena, Skin,Physiological Phenomenas, Skin,Physiological Phenomenon, Skin,Physiological Phenomenons, Skin,Process, Skin Physiological,Processes, Skin Physiological,Skin Physiological Concept,Skin Physiological Phenomenas,Skin Physiological Phenomenons
D013055	Spectrophotometry, Infrared	Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	IR Spectra,Infrared Spectrophotometry,IR Spectras,Spectra, IR
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog