Stem cell experiments conducted in space

Scientists are one step closer to manufacturing stem cells in space — which could speed up the development of new medical therapies on Earth — following experiments conducted on a private space mission by Cedars-Sinai researchers. The first data from these experiments has now been published in the journal NPJ Microgravity.

By introducing DNA into mature adult cells, scientists can reprogram them into a type of stem cell called induced pluripotent stem cells, which can then turn into other cell types. This process has been used for years to manufacture or replicate large numbers of cells for research and the development of new disease treatments.

Previous studies have found that when grown under microgravity, the near-weightlessness found in space, stem cells function differently. The lack of gravity could speed up cell manufacturing, according to Dr Arun Sharma, a research scientist in the Cedars-Sinai Board of Governors Regenerative Medicine Institute and co-senior author on the new study.

“Our goal has been to understand and harness those differences to more effectively and efficiently produce stem cells in a way that’s impossible on Earth,” Sharma said. “Cedars-Sinai is now the first to successfully introduce DNA into human induced pluripotent stem cells in space, establishing the foundation for our next step toward large-scale manufacturing of stem cells in space.”

The experiments took place aboard Axiom Mission 2, Axiom Space’s second astronaut mission to the International Space Station. During the mission, cells that had been frozen for transport were thawed and transferred into cell culture dishes by specially trained astronauts.

“Among the technical challenges associated with doing this kind of work in space was the challenge of keeping the cells in their dishes,” Sharma said. “On Earth, if we want to change the nutrients in a dish, we simply open the lid. In microgravity, if you open a lid, everything will escape. On this mission, we discovered that the surface tension of the fluid in 96-well plates commonly used in labs was enough to hold the cells in place in microgravity, meaning we didn’t need custom equipment for these experiments.”

Investigators on Earth, including lead author Dr Maedeh Mozneb, performed identical experiments so that the two sets of cells could be compared. The cells in space arranged themselves into three-dimensional spheres, rather than lying flat in a dish as they would on Earth.

“That was a very exciting surprise,” Sharma said. “We weren’t intending to grow the cells in three dimensions. The cells did that on their own. This makes sense, because in the microgravity found in space, things float around, and the cells floated and arranged themselves into spheres.”

This has made investigators think about the next step in the process of stem cell manufacturing, and how this new discovery might be used.

“We’ve since completed additional missions directed at making human induced pluripotent stem cells entirely in microgravity,” said Professor Clive Svendsen, Executive Director of the Board of Governors Regenerative Medicine Institute and co-senior author on the study. “These studies are ongoing and we hope will ultimately advance stem cell technology by providing a unique type of stem cell — one made in space.”

Image caption: Astronaut Rayyanah Barnawi of the Saudi Space Agency, the first Saudi woman in space, performed experiments for the Cedars-Sinai study. Photo courtesy of Axiom Space.