Lipid organization in pig stratum corneum.

The lipid and keratin structure of pig stratum corneum has been elucidated by small- and wide-angle X-ray diffraction. The measurements were carried out as a function of hydration and temperature. In addition, the stratum corneum was measured after recrystallization of the lipids at various temperatures. The results led us to conclude that the intercellular lipids in the stratum corneum are organized in at least two different lamellar structures with repeat distances of 6 and 13.2 nm. There is an indication for the presence of a third phase with a periodicity of 9 nm. The wide-angle pattern revealed a hexagonal (0.414 nm spacing) and liquid lateral packing (approximately 0.46 nm spacing). The 0.414 nm reflection started to decrease in intensity between 60 and 66 degrees C and disappeared between 72 and 95 degrees C. Furthermore, crystalline cholesterol has been indicated by both, wide- and small-angle X-ray diffraction, while the reflections of alpha-keratin were observed in the wide-angle X-ray diffraction pattern.