TU Wien prints skin tissue for research into inflammatory diseases without animal testing

Chronic inflammatory skin diseases such as psoriasis, atopic dermatitis (eczema), or acne are estimated to affect a large share of the population, but are considered difficult to reproduce in the laboratory. Animal experiments often yield results that transfer only to a limited extent, because animal skin differs significantly from human skin anatomically and immunologically. Researchers at TU Wien therefore rely on 3D bioprinting to produce controlled models that resemble human tissue and thus bring experiments closer to clinical reality.

In a recent review, the teams led by Aleksandr Ovsianikov and dermatology collaborators summarize how printed skin models can be adapted to different disease patterns.

“So far, various methods have been used to produce samples that are similar to human skin,” says Prof. Georg Stary of the Department of Dermatology at the Medical University of Vienna, a co-author of the study. “For example, you can embed connective-tissue cells in a collagen solution and culture them. But you have hardly any control over the spatial structure, the resulting cell layer is not particularly long-lasting, and it is hardly possible to integrate immune cells or blood vessels into the structure, which play a crucial role in chronic inflammation.”

“But that is very time-consuming and labor-intensive, and you have the problem of a lack of reproducibility,” says Georg Stary. “The samples often develop very differently, and you have little control over the structure that forms in this way.”

Self-assembly methods, in which cells use vitamin C to build up their extracellular matrix on their own, are also said to be “very time-consuming and labor-intensive” and suffer from variable reproducibility.

“We can solve exactly these problems with our 3D-printing method,” says Aleksandr Ovsianikov. “We build up three-dimensional tissue layer by layer from living cells, biopolymers, and carefully selected materials.”

“We have developed psoriatic models that contain T cells—the immune cells that trigger chronic inflammation in psoriasis,” says Andrea Gabriela Ulloa-Fernández (TU Wien). “With these models, you can study how the structure responds to specific medications.”

Technically, the process is similar to inkjet printing: a viscous bio-ink made of cells and hydrogels is deposited in fine droplets. The formulation is crucial, because the hydrogel type and cell mixture determine mechanics, diffusion properties, and cell interactions.

“With our method, we can precisely define the shape of the extracellular matrix in which the cells attach and proliferate,” says Ulloa-Fernández. “That gives us a completely different level of control over the end result than was previously possible. We hope our artificial skin models will now significantly advance research across a broad range of skin diseases.”