An initial project to this investigation was already underway last year: 250 test tubes containing human stem cells spent a month on the ISS1. By microgravity at an altitude of 400 kilometers, these cells successfully differentiated into the organ-like liver, bone, and cartilage structures. In comparison, the cells barely differentiated under gravity conditions on Earth. Therefore, tissue-supported skeletons have still been needed for their shaping. In the new experiments in orbit now, tissue stem cells from two women and two men of different ages will be studied to explore possible sex- and age-related differences.
The U.S. has also already used brain organoids in 2019 to study how microgravity affects the early development of the human brain2. In 2017, the U.S. company Emulate had experiments conducted on the International Space Station (ISS) using the company's brain chip systems3.
More information:
https://www.media.uzh.ch/de/medienmitteilungen/2021/UZH-Space-Hub.html
Sources:
1 https://www.media.uzh.ch/de/medienmitteilungen/2020/UZH-Space-Hub.html
2 https://health.ucsd.edu/news/releases/Pages/2019-07-08-2019-a-space-organoid.aspx
3 https://emulatebio.com/press/ncat-grant-to-fund-hes-aboard-iss/