iss spacewalk

Human tissues to be grown in microgravity conditions aboard the ISS

Experiments to see how human tissue will grow in zero-gravity conditions are to be conducted onboard the International Space Station (ISS).

Researchers at Airbus and the University of Zurich (UZH) plan to send materials up with the next supply flight for the ISS that will enable astronauts to grow three-dimensional organ-like tissues called organoids.

The organoids, which will be grown from human adult stem cells, cannot be produced on Earth because they require supporting skeletons due to the effect of gravity.

3D organoids are of great interest to pharmaceutical companies because they could allow drugs to be tested directly on human tissue which could produce more reliable results and eliminate the need for animal models.


Organoids grown from patient stem cells could also be used in the future as building blocks for tissue replacement therapy for damaged organs. Globally, the number of donated organs is far from sufficient to meet demand.

Initial preparatory tests on the ISS 18 months ago were successful. In this experiment, 250 test tubes containing human stem cells that spent a month on board the space station showed differentiated organ-like liver, bone and cartilage structures that developed as intended from the tissue stem cells.

In contrast, the cultures created on Earth, which were grown as controls under normal gravity conditions, showed no or only minimal cell differentiation.

In the current mission, tissue stem cells from two women and two men of different ages are being sent into space.

The researchers are testing how robust the method is when using cells of different biological variability. They expect production to be easier and more reliable in microgravity than using support structures to grow on Earth.

“Currently, the focus is on production engineering issues and quality control,” said UZH scientist Oliver Ulrich.

“With regard to the envisaged commercialisation, we now have to find out how long and in what quality we can keep the organoids grown in space in culture after their return to Earth.”

Airbus project manager Julian Raatschen said: “If successful, the technology can be further developed and brought to operational maturity. Airbus and the UZH Space Hub can thus make a further contribution to improving the quality of life on Earth through space-based solutions.”

The sample material will return to Earth at the beginning of October with the first results expected from November.

In June, an additional solar array was deployed on the ISS to give the station a much needed electricity boost as demand for low-gravity experiments and space tourism grows.

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