Human in vitro models instead of animal experiments and cell lines
The discovery of human induced-pluripotent stem cells (hiPS cells) has given scientists the opportunity to overcome many limitations of classical animal models, which is leading to a paradigm shift in the development of personalized and disease-specific model systems. Specifically, the principle of organ-on-a-chip systems has evolved over the past few years from a conceptual idea to a possible alternative for animal models. Science, industry and public authorities now universally recognize the potential of these systems.
Organ-on-a-chip systems combine the unique features of classical cell assays (human genetic background) and animal models (3D tissue and blood circulation). They make it possible to reduce the need for animal experiments according to the 3R principle (Replace, Reduce, Refine). Furthermore, they improve the translatability of preclinical results to clinical phases and thus make the entire development process more cost-effective, safer and faster.
Basic building blocks of an organ-on-a-chip
In the Attract Group "Organ-on-a-chip", different microphysiological organ-on-a-chip systems, also known as microphysiological systems (MPS), are being developed that replicate the in vivo structure and functionality of the respective organs.
Microphysiological environment
The primary component of these systems is the microphysiological environment. For this purpose, technologies from the fields of microfabrication, materials science and microfluidics are used to create structures that physiologically mimic in vivo conditions. The use of microfluidics enables the work with physiologically relevant small quantities of liquids and allows for the transfer and removal of soluble factors such as nutrients, drugs or metabolites.
Human tissue
The second important component is the integration of human tissue, which is done by the use of hiPS cells instead of cell lines. By targeted differentiation of hiPS cells, it is possible to obtain cell types and tissues that have been difficult or impossible to isolate from primary biopsies. hiPS cells can be cryopreserved and expanded, making them far better suited for industrial applications that require reproducible and standardized models. In contrast to embryonic stem cells, the use of hiPS cells is not ethically problematic.
Applications of organs-on-chips
Organ-on-a-chip systems are envisioned to be primarily used for efficacy and toxicity testing during the preclinical screening of drugs.
Additional applications exist in almost every area where animal experiments are in use, such as biomedical basic research and the cosmetic industry, where there is a great demand for alternative methods because the EU will ban the import of all cosmetics tested on animals.
Another promising field of application is personalized medicine. This area is still immature, but it has great long-term potential.
Fraunhofer Institute for Interfacial Engineering and Biotechnology