A radiant beauty, special care for the mature skin, a pure teint – all this and even more the cosmetic industry is promising when we buy their products. However, before the praised creams, body lotions and pharmacological tinctures appear on the market, they have to be tested thoroughly on their skin compatibility and effects. In many cases animal testing is inevitable. But more and more consumers – as well as legislators – disapprove that animals have to suffer for beauty. Researchers at the Fraunhofer-Institut für Grenzflächen und Bioverfahrenstechnik IGB (Fraunhofer Institute for Interfacial Engineering and Biotechnology), therefore now present a novel alternative and a supplement to animal testing: the skin testing system AST-2000, a three-dimensional whole skin model developed on behalf of the CellSystems company.

Up to now, to circumvent animal testing, tests are carried out using cell cultures or animal bioptic materials. The predictivity of these prevailing alternative tests is often not accurate or extensive enough. This is, because only single cells of animal or human origin are applied or only one single cell type is used, e.g. cells of the epidermis (upper skin). Interactions with the dermis – laying below the epidermis – therefore cannot be tested. “Better are organ-like cultures – a kind of artificial skin – as for example three-dimensional human skin models. They consist of dermal and epidermal components and therefore are physiologically comparable to the natural skin” Thomas Graeve from the IGB explains. The scientist succeeded in developing such a three-dimensional whole skin-model from human bioptic material. This skin equivalent consists of dermal fibroblasts and a multi-layered epidermis which even builds up a horny layer (stratum corneum). The skin model is very similar to the living human skin in structure as well as in function. “The organotypical function of the model was demonstrated by the new formation of a basement membrane, an interfacial layer between epidermis and dermis” Thomas Graeve says.

The three-dimensional skin-model can be used in a wide variety of applications. For example it is suitable as an alternative testing system for cosmetics: Using the in-vitro model it can be tested if certain creams cause skin irritations or allergic reactions. The equivalent can even be applied in pharmacology, e.g. for examining the process of wound healing. And furthermore, immunological, histological and molecular biological investigations are possible with AST-2000. The researchers want to extend the model by selective addition of melanocytes - the skin's pigment cells. This would enable to test the mode of action of self-tanning lotions. In industry the new whole skin model is already being applied. The company CellSystems currently prepares its world-wide distribution.