Interaction of phosphatidylcholine liposomes with the human stratum corneum

• Published in: Biochimica et biophysica acta 1995-07, Vol.1237 (2), p.176-182
• Main Authors: Zellmer, Sebastian, Pfeil, Wolfgang, Lasch, Jürgen
• Format: Article
• Language: English
• Subjects: Calorimetry; Calorimetry, Differential Scanning; Confocal laser scanning microscopy; Fluorescent Dyes; Humans; Liposome; Liposomes; Microscopy, Confocal - methods; Penetration; Phosphatidylcholines - metabolism; Phosphatidylethanolamines; Rhodamines; Skin; Skin - metabolism; Thermodynamics
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/0005-2736(95)00100-H

The interaction of dimyristoylphosphatidylcholine liposomes with the human stratum corneum was investigated by confocal laser scanning microscopy and differential scanning calorimetry. Human skin is characterized by a high autofluorescence. By introducing appropriate optical filters the autofluorescence of the skin was depressed and the penetration profile of fluorescence labelled vesicles was investigated. From optical sectioning it was obvious that neither the vesicles nor the fluorophore N-(lissamine rhodamine B sulfonyl)diacylphosphatidylethanolamine (Rho-PE) penetrates in detectable amounts into the human skin. Differential scanning calorimetry of human stratum corneum revealed, that the peak positions of the human stratum corneum specific endothermic transitions at 10°C, 35°C, 50°C, 62°C, 73°C and 81°C did not change significantly after 18 h of non-occlusive vesicle application. However, the enthalpy of the transitions at 35°C, 50°C, 62°C and 73°C, estimated through peak heights increased, relative to the protein related peak at 81°C. A novel transition at 10°C was observed. From these data we conclude that DMPC liposomes do not penetrate intact into the human skin. We deduce, however, that the vesicles disintegrate at the surface of stratum corneum after non-occlusive application. The individual lipid molecules then interact with the lipid barrier of the stratum corneum and penetrate into the latter, which results in an increase of the enthalpy, related to the lipid components of the SC.