Human Skin Models for Research Applications in Pharmacology and Toxicology: Introducing NativeSkin®, the “Missing Link” Bridging Cell Culture and/or Reconstructed Skin Models and Human Clinical Testing

The use of human skin models in pharmacology and toxicology has become a widely accepted approach for the evaluation of dermato-cosmetic products, both finished formulations and active ingredients. In particular, in vitro–reconstructed human skin models consisting on human keratinocytes and/or fibroblasts are used globally in both industrial and academic research laboratories, and regulatory bodies endorse the use of several of them as valid alternatives to animal testing requirements. Despite the recent progress that has been made in the reconstruction of more complex skin models containing other cell types, such models still have inherent limitations, as they are not an exact copy of human skin in vivo, and hence the predictability of the human in vivo response remains limited. Here we describe a new testing approach based on the use of NativeSkin®, a standardized ex vivo model of human skin, maintaining physiological skin biology, skin barrier function, and metabolism during 7 days of culture in tissue culture inserts. NativeSkin models are cultivated in quality-controlled and assured conditions, and demonstrate high reproducibility among donors. Where initial product testing is often performed on skin cell cultures and in vitro–reconstructed models, we propose the use of NativeSkin being the most complete skin model available, as highly predictive and cost-effective “last-line screen in laboratory conditions” prior to clinical evaluation in humans.