Mickael Puginier , Marisa Meloni , Mathilde Bergal  and Alicia Roso 
2017, Eurotox 53rd congress
In vitro reconstructed human tissue models are recognized as being sensitive and reliable models to replace or reduce laboratory animal use in preclinical studies.On top of validated method for skin irritation that apply defined procedures, new and predictive experimental protocols can be designed addressing medical device and dermo-pharmaceutical specific applications. In this purpose, the status of the skin barrier (intact or injured) is a key parameter. The study objective was to apply 3-D Reconstructed human Epidermis models (RhE) with a physically impaired barrier function (reproducible mechanical superficial abrasion at stratum corneum level) as a new tool in a preclinical testing strategy.
The skin tolerance was determined by (1) cellular viability (MTT test); (2) barrier function (TEER measurement and Biotin permeability); and (3) morphological evaluation (Hematoxylin Eosin Staining). Ingredients with different chemical structures and functionalities were tested in aqueous dilutions at usual doses and compared to negative and positive controls. Short chain surfactants including Sodium Dodecyl Sulfate treated tissues presented expected adverse effects, consistent with barrier disruption. Other emulsifying, thickening, moisturizing ingredients appeared well tolerated. Moreover, it has been possible to appreciate not only the toxicity but also the homeostasis recovery mechanisms linked to the relative composition (e.g. fatty chain length) and allow us to better understand their interactions with the living epidermis. This Multiple Endpoints Analysis (MEA) approach permitted to assess ingredients irritation potential at cellular, morphological, functional level and to evaluate the overall biocompatibility of products applied directly on tissues with impaired barrier functions.
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