Unravelling Barrier Properties of Three Different In-House Human Skin Equivalents
Authors
Thakoersing VS, Gooris G, Mulder AA, Rietveld M, El Ghalbzouri A, Bouwstra JA
Institution
Leiden University, Drug Delivery Technology, Leiden
Country
Netherlands
Year
2011
Journal
Tissue Engineering
Abstract
Human skin equivalents (HSEs) are 3 dimensional culture models that are used as a model for native human skin. In this study the barrier properties of two novel HSEs, the Fibroblast Derived matrix Model (FDM) and the Leiden Epidermal Model (LEM), were compared with the Full Thickness collagen Model (FTM) and human skin. As the main skin barrier is located in the lipid regions of the upper layer of the skin, the stratum corneum (SC), we investigated the epidermal morphology, expression of differentiation markers, SC permeability, lipid composition and lipid organization of all HSEs and native human skin. Our results demonstrate that the barrier function of the FDM and LEM improved compared to that of the FTM, but all HSEs are more permeable than human skin. Furthermore, the FDM and LEM have a relatively lower free fatty acid content than the FTM and human skin. Several similarities between the FDM, LEM and FTM were observed: 1) the morphology and the expression of the investigated differentiation markers were similar to that observed in native human skin, except for the observed expression of keratin 16 and premature expression of involucrin which were detected in all HSEs 2) the lipids in the SC of all HSEs were arranged in lipid lamellae, similar to human skin, but show an increase in the number of lipid lamellae in the intercellular regions and 3) the SC lipids of all HSEs show a less densely packed lateral lipid organization compared to human SC. These findings indicate that the HSEs mimic many aspects of native human skin, but differ in their barrier properties.