Skin from a factory – this has long been the dream of pharmacologists, chemists and doctors. Research has an urgent need for large quantities of ‘skin models’, which can be used to determine if products such as creams and soaps, cleaning agents, medicines and adhesive bandages are compatible with skin, or if they instead will lead to irritation or allergic reactions for the consumer. Such test results are seen as more meaningful than those from animal experiments, and can even make such experiments largely superfluous.
But artificial skin is rare. “The production is complex and involves a great deal of manual work …
An interdisciplinary team of Fraunhofer researchers is currently developing the first fully automatic production system for two-layer skin models. “Our engineers and biologists are the only ones who have succeeded in fully automating the entire process chain for manufacturing two-layer skin models,” explains Saxler, who is from the Fraunhofer Institute for Production Technology IPT where he is responsible for technology management and heads the “Life Science Engineering” business unit. In a multi-stage process, first small pieces of skin are sterilized. Then they are cut into small pieces, modified with specific enzymes, and isolated into two cell fractions, which are then propagated separately on cell culture surfaces. The next step in the process combines the two cell types into a two-layer model, with collagen added to the cells that are to form the flexible lower layer, or dermis. This gives the tissue natural elasticity.
In a humid incubator kept at body temperature, it takes the cell fractions less than three weeks to grow together and form a finished skin model with a diameter of roughly one centimeter. The technique has already proven its use in practice, but until now it has been too expensive and complicated for mass production. Mertsching explains, “The production is associated with a great deal of manual work, and this reduces the method’s efficiency.”