Among skin models, reconstructed human epidermis are largely used in cosmetic domain either to evaluate compounds activity or for regulatory tests such as toxicity. They represent a good alternative to animal testing. These 3D model of skin epidermis are simpler than full reconstituted skin, are easier to prepare and can also be purchased from various companies. But are they representative of physiological skin? For which applications?
We investigated one aspect of this question basing our research on knowledges of skin microenvironment. Inside the skin, cells are submitted to a low oxygen level varying for one layer to another. In the basal part of the epidermis, oxygen partial pressure decreases to 1.5-3%, a condition called physioxia. Moreover, skin aging is associated with oxygen level decrease. These levels are very far from the classical conditions used to maintain cells in culture. In fact the oxygen partial pressure in an incubator is around 18-19%, what is called normoxia.
In the current study, we present the comparison of the preparation of reconstructed epidermis in physioxia and in normoxia and their characterization in terms of morphology, proliferative potential, and differentiation but also their capacity to answer to oxidative stress, a crucial activity for skin health preservation.
This presentation shows the importance of taking into account the oxygen parameter in reconstructed epidermis model and particularly in the case of biological activity studies.