The 33rd SpaceX commercial resupply mission will launch from NASA's Kennedy Space Center in Florida on Sunday, August 24th, for the International Space Station (ISS). Along with a regular complement of sundries, this mission will carry numerous science investigations, like a 3D bioprinted implantable medical device, engineered liver tissues, and another 3D metal printing experiment. In addition, the mission will send an important medical investigation examining potential bone density loss, a common health effect that comes from extended periods spent in microgravity.
Ongoing experiments aboard the ISS have shown that astronauts experience a gradual loss in bone density, even with consistent exercise and resistance training using the station's equipment. The investigation will test how microgravity affects bone-forming and bone-degrading cells, which could help astronauts guard against bone density loss during long-duration missions to the Moon and Mars. It will also have applications for millions of people here on Earth, potentially leading to new treatments for people suffering from osteoporosis.
Previous research into the effects of microgravity on the human body has shown that astronauts typically lose around 1 to 2% of their bone density per month. While medical research has documented how bones grow and age here on Earth, many unanswered questions remain about how and why they weaken in microgravity. Specifically, the Microgravity Associated Bone Loss-B (MABL-B) investigation will focus on mesenchymal stem cells (MSCs), which are responsible for building new bone tissue in the body as the cells mature.
The experiment will build on the MABL-A mission, which found that microgravity promotes signalling from a protein called Interleukin 6 (IL-6). This protein is produced by various cells in the body and acts as both a pro-inflammatory and an anti-inflammatory mediator in the immune system. Therefore, the MABL-A findings suggest that increased signalling from this protein enhances bone degeneration in microgravity. The MABL-B experiment will investigate this by testing ways to block IL-6 signalling pathways. It will consist of mesenchymal stem cells and bone cells grown and cultured for 19 days in specialized medical containers aboard the ISS.
Crew members will periodically collect samples for analysis back on Earth to determine the role of the IL-6 protein in bone degeneration. This research could lead to targeted treatments for the Artemis astronauts as they return to the Moon (this time, to stay!) and those who will venture to Mars in the coming decades. As missions venture farther from Earth, maintaining crew health is especially important since opportunities for medical evacuation will not be possible. It could also lead to treatments for people who have osteoporosis and other degenerative bone diseases.
Further Reading: NASA