Experiments in space have revealed a new perspective into biological sciences, including insights into making human tissue. Gravity influences cellular behavior by impacting how protein and genes interact inside the cells, creating tissue that is polarized, a fundamental step for natural organ development. Unfortunately, gravity is against us when trying to reproduce complex tissues in the lab.
When it comes to building organized tissues in the lab, scientists use scaffolds to provide a surface for cells to attach based on a predetermined rigid shape. This strategy helps the tissue to organize in the early stages but creates problems down the road, such as eventual immune reactions to the synthetic scaffolds or inaccurate structures. However, in the weightless conditions of space, cells can freely organize into their correct three-dimensional structure without the need for a scaffold substrate. By removing gravity, researchers may learn new ways of building human tissues, such as cartilage and blood vessels that are scaffold free, mimicking their natural cellular arrangement in an artificial setting.
While this is not exactly what happens in the womb, weightless conditions do provide an advantage. Experiments like these are what is happening way up there at the International Space Station. By recreating embryonic organ formation in space, we can anticipate how the human body would develop in the womb. These experiments help researchers optimize tissue growth for use in basic science, personalized medicine, and organ transplantation.