Effects of growth conditions on the barrier properties of a human skin equivalent.
OBJECTIVE
Development of transdermal and topical formulations requires extensive skin permeation testing and the availability of reproducible test models. We have worked on development of a Human Skin Equivalent (HSE) by culture with a combination of additives, including the PPAR-alpha agonist clofibrate, in order to simulate the cutaneous barrier of human skin.


METHODS
HSEs were constructed by culturing human keratinocytes on dermal matrices consisting of human fibroblasts and collagen and cultured in specific growth conditions (combination of clofibrate, ascorbic acid and fatty acids). The resulting HSEs were characterized for their morphology, lipid composition and permeability profile and compared to human skin and EpidermFT.


RESULTS
The unique media growth additives combination normalized the lipid profile and significantly increased the permeability barrier of the HSEs to caffeine and hydrocortisone (p < 0.05). The HSEs overestimated the permeation of most compounds by 2-7 fold as compared to human skin. The permeability profiles obtained though were very similar and not significantly different (p < 0.05) from those of EpidermFT.


CONCLUSIONS
Culture with the growth media additives combination produced a pronounced effect on the permeability barrier of the HSEs. Further validation of permeability with additional agents could comprise the first step toward their use in skin permeability screening.
Ernest Mario School of Pharmacy, Rutgers-The State University of New Jersey, Piscataway, New Jersey, USA.
Priya
P
Batheja
Yifan
Y
Song
Philip
P
Wertz
Bozena
B
Michniak-Kohn
D000924:Anticholesteremic Agents / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology; D002478:Cells, Cultured; D002994:Clofibrate / Q000494:pharmacology*; D024042:Collagen Type I; D005227:Fatty Acids / Q000494:pharmacology; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008055:Lipids / Q000032:analysis; D008954:Models, Biological; D047493:PPAR alpha / Q000037:antagonists & inhibitors*; D010539:Permeability / Q000187:drug effects*; D004364:Pharmaceutical Preparations / Q000378:metabolism; D012867:Skin / Q000737:chemistry / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D017768:Skin, Artificial; D023822:Tissue Engineering / Q000379:methods*
D000924:Anticholesteremic Agents; D024042:Collagen Type I; D005227:Fatty Acids; D008055:Lipids; D047493:PPAR alpha; D004364:Pharmaceutical Preparations; D002994:Clofibrate; D001205:Ascorbic Acid