Direct visualization of lipid domains in human skin stratum corneum's lipid membranes: effect of pH and temperature.

I. PLASENCIA-GIL; L. NORLÉN; LUIS A. BAGATOLLI

BIOPHYSICAL JOURNAL

CELL PRESS

Lugar: United States; Año: 2007 vol. 93 p. 3142 - 3142

0006-3495

he main function of skin is to serve as a physical barrier between the body and the environment. This barrier capacity is in turn a function of the physical state and structural organization of the stratum corneum extracellular lipid matrix. This lipid matrix is essentially composed of very long chain saturated ceramides, cholesterol, and free fatty acids. Three unsolved key questions are i), whether the stratum corneum extracellular lipid matrix is constituted by a single gel phase or by coexisting crystalline (solid) domains; ii), whether a separate liquid crystalline phase is present; and iii), whether pH has a direct effect on the lipid matrix phase behavior. In this work the lateral structure of membranes composed of lipids extracted from human skin stratum corneum was studied in a broad temperature range (10 degrees C-90 degrees C) using different techniques such as differential scanning calorimetry, fluorescence spectroscopy, and two-photon excitation and laser scanning confoca