Immortalized equivalent human epidermis as a platform to evaluation hair dyes toxicity: Efficiency comparison between...

The use of 3D models in various scientific applications is becoming more popular to replace traditional monolayers models. In this work, we used a three-dimensional in-house model of epidermis using HaCaT immortalized cells to evaluate the dermal toxicity induced by Basic Blue 99 and Basic Red 51, both present in commercial hair dye formulations. Our data show that cells cultured in the 3D model respond differently to those cultured in monolayer. Basic Red 51 dye induces apoptosis an DNA breaks in both models, however, these effects is more pronounced in cells cultured in monolayer. The toxic mode of action of Basic Blue 99 seems to be the induction of cell death, without genotoxic effects, but while the necrotic pathway is observed in HaCaT monolayer cell culture, was apoptosis seen in the Equivalent Human Epidermis (EHE) model. We could also confirm that cells in EHE model, an environment that could better mimic human effects, react differently to chemical stressors than the cells cultivated in 2D.