ABSTRACT
The skin barrier against chemicals, surfactants, and UV irradiation is its outermost layer, the stratum corneum (SC). SC has a heterogeneous structure, composed of corneocytes embedded in the intercellar lipid lamellae. Ordering of the lipid bilayer is associated with the main epidermal barrier. Knowledge of the lipid structure is important in understanding the mechanism of irritant dermatitis and other SC diseases. The ordering (or fluidity) change of the lipid bilayer is measured by the analyses of aliphatic spin probes incorporated into intercellar lamella lipids using electron paramagnetic resonance (EPR) (1-5). The EPR spin probe method measures nondestructively the ordering of the lipid bilayer of SC.
