The human heart acts strangely in space. Research shows that mini-hearts made from human stem cells grow much faster in the microgravity of space than in labs on Earth.
In space, astronauts face unique challenges. The lack of gravity changes how blood flows. This can make their hearts shrink and change shape, often becoming rounder. Arun Sharma, from the Center for Space Medicine Research at Cedars-Sinai Medical Center, shared that even heart muscle cells sent to the International Space Station (ISS) degrade over time. They lose their ability to contract, and their metabolism shifts.
However, when scientists tried growing human mini-hearts in space, they found success. They could produce these proto-hearts more easily than on Earth. “In space, we can actually create them from scratch,” Sharma explained. “Microgravity might help the production process.” For the last several years, Sharma has been sending heart cell experiments to the ISS, believing that the conditions there can enhance heart cell growth.
The process to create these mini-hearts involves using bioreactors that mimic space conditions on Earth. In space, however, the cells can float freely without agitation, which they prefer. “We’ve noticed a significant boost in organoid production,” Sharma noted, though he hasn’t shared exact numbers yet.
Sharma sees a future where these mini-hearts could help patients awaiting heart transplants. While no space-grown hearts have been used in patients so far, there’s hope that they could lead to better treatments. Currently, researchers are using heart muscle patches made from induced human stem cells on Earth to assist patients with heart damage. These patches are crucial since the heart can’t heal itself. Sharma believes that organoids grown in space might be of higher quality, resulting in stronger patches that are less likely to collapse when returned to Earth.
Even though it’s a lengthy process to take these space innovations to human trials, Sharma believes that the first trials could involve testing new heart disease medications using these organoids. Heart disease remains a leading cause of premature death worldwide, making advancements in treatment vital. Millions die from heart issues every year, and stem cell therapies offer hopeful new options.
Sharma’s team is excited about future research. They will send more heart cell experiments on NASA’s SpaceX CRS-35 mission later this year, continuing to explore the potential of growing heart tissue in space.
For more information on heart disease statistics, check out the British Heart Foundation’s detailed reports here.
