Penetration route of functional molecules in stratum corneum studied by time-resolved small- and wide-angle x-ray diffraction

Abstract

Abstract. We studied effects of functional molecules on corneocytes in stratum corneum using time-resolved small-and wide-angle x-ray diffraction after applying a functional molecule. From these results it was revealed that in the stratum corneum a typical hydrophilic molecule, ethanol, penetrates via the transcellular route and on the other hand a typical hydrophobic molecule, d-limonene, penetrates via the intercellular route.

Permeation through a lamellar stack of lipid mixtures

“…On a much larger tissue scale, an important system is the stratum corneum, which constitutes the outermost layer of human skin [5]. It is known that the stratum corneum is composed of corneocytes and intercellular lipids that form lamellar structures [6]. Although stratum corneum lipids from a gel phase with limited mobility at physiological temperatures, the lipid tail-tail interface of each bilayer is in a liquid-like disordered state [7].…”

“…( 3) is analogous to that of the inplane correlation function of an Ising spin system. For the one-phase region (T > T c ), the correlation function is given by S i,ρ S i,ρ+r ∼ exp(−r/ξ), (6) where r = |r| and ξ is the correlation length. Close to the critical point, the correlation length as a function of temperature scales as ξ ∼ |τ − τ c | −ν , where ν is the corresponding critical exponent.…”