Property characterization of reconstructed human epidermis equivalents, and performance as a skin irritation model.

In recent years, in vitro skin models combining cell biology and tissue engineering have been developed in order to replace animal models for toxicological studies and to serve as research support to better understand skin biology. This study reports the development and characterization of a epidermal tissue equivalent meant to be used to develop and to evaluate the effect of applied cosmetic ingredients, and for alternative toxicological testing. This epidermis equivalent model was characterized relative to the morphological characteristics of short- and long-term maintained tissues by performing histological studies.

Evaluation of THP-1 cell line as an in vitro model for long-term safety assessment of new molecules.

Objective: Monitoring the chronic and subacute toxicity is essential in the development of new cosmetic ingredients. In response to the present lack of validated alternative methods, we developed an in vitro model for repeated dose cytotoxicity on THP-1 cells.

Methods: Cultured in suspension, cells were treated with chemicals for 14 days with a frequency of three applications per week, and cell viability was determined by MTT assay.

Image analysis to quantify histological and immunofluorescent staining of ex vivo skin and skin cell cultures.

Image processing steps and analysis techniques were developed for the quantification of photomicrographs obtained from light and fluorescence microscopy. The substrates examined were either skin cell cultures, such as normal human keratinocytes (NHK) or fibroblasts, or ex vivo skin sections. Examples of the analyses are provided for the comparison of skincare active ingredient treated samples vs.

Cotton honeydew (Gossypium hirsutum L.) extract offers very interesting properties for hair cosmetics and care products.

Cotton honeydew extract is composed of a unique combination of oligosaccharides, including fructose, glucose, inositol, melezitose, saccharose, trehalose and trehalulose. Studies have shown that these oligosaccharides exhibit a protective effect. Therefore, we were interested in studying the effect of these oligosaccharides on normal and damaged human hair.