Physical and chemical perturbations of the supramolecular organization of the stratum corneum lipids: in vitro to ex vivo study.
BACKGROUND
FTIR spectroscopy is classically used to study the supramolecular organization of the stratum corneum lipids. Exposure to UV(A) is responsible for a small decrease in packing observed on cutaneous lipid films.


METHODS
Lipid films and human skin biopsies were either exposed to UV(A) irradiation of 120 J/cm(2), UV(B) irradiation of 0.15 J/cm(2) or put in contact with ethanol. Using FTIR in vitro and IR microspectroscopy ex vivo provided information on: i) the precise localisation of the stratum corneum in the skin, ii) its thickness, and iii) the organization of its constituted lipids.


RESULTS
Different action modes were observed for UV irradiation and the contact with ethanol with a certain destabilisation of the lipidic layer. Ethanol was also found to be responsible for the creation of pores. The destabilisation of the lipid cement was mainly observed ex vivo.


CONCLUSIONS
The barrier function of the skin is affected by the action of physical and chemical external agents at the molecular level. The increased laxity of the lipid packing could enable the percutaneous penetration velocity of actives.
Merle
C
C
Group Chimie Analytique de Paris-Sud EA 4041, IFR 141 School of Pharmacy, Univ. Paris-Sud F. 92296 Châtenay-Malabry Cedex, France. chloe.merle@club-internet.fr
Baillet-Guffroy
A
A
D000328:Adult; D055592:Biophysical Phenomena; D002518:Ceramides / Q000737:chemistry; D004817:Epidermis / Q000737:chemistry* / Q000528:radiation effects; D000431:Ethanol; D005260:Female; D006801:Humans; D006860:Hydrogen Bonding; D066298:In Vitro Techniques; D008055:Lipids / Q000737:chemistry* / Q000528:radiation effects; D046911:Macromolecular Substances / Q000737:chemistry; D008823:Micelles; D008958:Models, Molecular; D017550:Spectroscopy, Fourier Transform Infrared; D014466:Ultraviolet Rays
D002518:Ceramides; D008055:Lipids; D046911:Macromolecular Substances; D008823:Micelles; D000431:Ethanol