An organism-on-a-chip will replace animal models

For medical research, animal experiments have always been an unavoidable evil. However, researchers at the Fraunhofer Institute in Dresden managed to develop a promising alternative – a "mini-organism" inside a chip. Its use will allow realistic reproduction of complex metabolic processes occurring in the human body.

 
Using a miniature multi-organ chip
(instead of a scale ruler, a 1 euro coin was placed on it),
having three separate microcircuits, researchers can study
regeneration of a certain type of kidney cells and much more.

Researchers around the world are looking for alternatives to animal models, but this task is extremely difficult. To understand the effect exerted on the body by a particular compound, it is not enough to test it on isolated samples of tissues or cells. Most medications have a systemic effect on the body, that is, they affect all systems and organs. As a result, toxic substances that often appear in the process of metabolic processes can damage organs other than target organs.

Together with colleagues from the Technical University of Berlin, researchers at the Fraunghofer Institute have developed a new approach that can save the field of biomedical research from the need for animal experiments. The multi-organ chip developed by them reproduces complex metabolic processes of the human body with amazing accuracy on a scale of 1:100,000.

Different types of human cells can be inserted into different compartments of the chip. These "mini-organs" are connected to each other with the help of the thinnest channels through which, with the help of a tiny pump acting as a heart, the nutrient medium is constantly pumped. The configuration of the chip, that is, the number of mini-organs and the channels connecting them, can be modified depending on the tasks facing the researchers and the purpose of the study. Such a chip allows not only to test the active ingredients of new medicines, but also to study the effect of cosmetics on the skin.

The concept of combining samples of cells of various types and microfluidic channels has long been studied by scientists. However, the new system has two distinctive advantages over traditional approaches.

Firstly, it is exclusively miniaturized. The micro-pump used in it is capable of providing a very low flow rate of liquid in microchannels, not exceeding 0.5 microliters per second. The developers claim that this indicator corresponds to what is happening in the body.

Secondly, the microfluidic system provides a continuous flow of liquid medium, which, like blood in a living organism, washes the entire complex of "mini-organs" built into the chip. This factor is extremely important, since certain types of cells acquire their characteristic morphology only when stimulated by fluid flow.

To study the effect of a chemical compound on the body, researchers put cells of various types into a chip. After that, the nutrient medium containing it is injected into the cell population corresponding to the organ through whose bloodstream the compound enters the body in reality. In the future, the chip reproduces the metabolic reactions of the body to the analyzed substance. In such experiments, cells of people of different genders and ethnicities can be used. Also, at a scale of 1:100,000, you can set variations in body size and weight. The chip allows you to observe which metabolic products are formed in certain cell populations and what effect they have on the cells of other organs. The results obtained in this case are even more predictable than the results of animal experiments.

According to one of the developers, Dr. Frank Sonntag, in addition to studying the effect of active ingredients on the body, the new chip may have another application. To date, it is known that endothelial cells play a key role in the development of almost all kidney diseases. When conducting all existing laboratory tests, specialists invariably face the problem that endothelial cells can function only in conditions of constant fluid flow. The use of a new chip will eliminate this problem, and will also allow us to study the process of restoring kidney endothelial cells after damage.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Fraunhofer-Gesellschaft materials:
Mini synthetic organism instead of test animals.

06.02.2015