3D-printed skin imitation equipped with living cells could replace animal testing

Directive 2010/63/EU laid down restrictions on animal testing for the testing of cosmetics and their ingredients throughout the EU. Therefore, there is an intense search for alternatives to test the absorption and toxicity of nanoparticles from cosmetics such as sun creams.

A team of researchers from Graz University of Technology (TU Graz) and the Vellore Institute of Technology (VIT) in India is working on the development of skin imitations that mimic the native three-layer tissue structure and biomechanics of human skin. Such imitations can be produced using 3D printing and consist of hydrogel formulations that are printed together with living cells.

"The hydrogels for our skin imitation from the 3D printer have to fulfill a number of requirements," says Karin Stana Kleinschek from the Institute of Chemistry and Technology of Biobased Systems. "The hydrogels must be able to interact with living skin cells. These cells not only have to survive, but also have to be able to grow and multiply."

The starting point for stable and 3D-printable structures are hydrogel formulations developed at TU Graz. Hydrogels are characterized by their high-water content, which creates ideal conditions for the integration and growth of cells. However, the high-water content also requires methods for mechanical and chemical stabilization of the 3D prints.

Image source: Manisha Sonthalia - Vellore Institute of Technology.