Stratum corneum, corneodesmosomes and ex vivo percutaneous penetration.

摘要: The stratum corneum is composed of cornified keratinocytes, joined together with corneodesmosomes and embedded in the relatively hydrophobic intercellular substance. Formation this horny layer its constant desquamation are fundamental processes leading to establishment an efficient epidermal barrier. We examined structural changes occurring ex vivo, order better understand mechanisms regulating corneocyte at surface influencing percutaneous penetration exogenous substances. Morphologic modifications were induced by occlusion, increasing tissue hydration, or application propylene glycol, a hydrophilic solvent small molecular size. Distribution major antigens, markers terminal differentiation, was studied immunohistochemically showed no modification related alteration. Skin samples fixed paraformaldehyde either postfixed OsO4 Epon RuO4 epoxy acrylic resins. Structural composition spatial organization elements present intercorneocyte spaces evaluated ultrastructurally, special attention paid fate corneodesmosomes. Our results suggest that spontaneous lipids excreted into constitution lamellar multilayers lower origin partition compartment domains. latter, compatible proteinic contents, seem be displaced components undergoing reorganization, towards invariable foci represented This mechanism may involved delivery proteolytic enzymes, thus contributing progressive degradation corneodesmosomal proteins.