What do you do when you’re studying age-related diseases but can’t wait around for tissue models to reach a ripe old age? You blast them into outer space, naturally.
It’s no secret that after traveling in space, astronauts’ bodies experience changes that resemble aging: bone loss, muscle deterioration and altered immune systems, to name a few. These result from prolonged exposure to microgravity, or gravity that is “diminished or close to zero gravity compared with Earth.” Scientists at the National Institutes of Health (NIH) and the International Space Station (ISS) are harnessing these age-accelerating effects to create models of various age-related diseases, a process that includes sending tissue models into space.
Tissue chips—also called tissue-on-a-chip or organ-on-a-chip—are tiny 3D models of human organ systems. Scientists use them to model diseases and test how drugs might affect specific organs. The NIH struck a deal this week with StemoniX to use its brain-on-a-chip technology in opioid research.
"Tissue chips in space provide a way to model various diseases of the aging process. Such models can be difficult or take a long time to develop here on earth but are greatly facilitated under microgravity, and scientists can use them to develop drugs that can prevent or slow down those diseases," said Danilo Tagle, Ph.D., associate director for special initiatives at NIH’s National Center for Advancing Translational Sciences (NCATS), in a statement. "Taking this technology into space is an unprecedented opportunity to use tissue chips for accelerating translational development of interventions for use here on earth to treat many aging-related diseases.”
NCATS, the NIH’s National Institute of Biomedical Imaging and Engineering, along with the ISS U.S. National Laboratory, are supporting research under their Tissue Chips in Space program. The first set of chips—developed at the University of California, San Francisco to model the immune system—arrived at the ISS in December. A second shipment is due to blast off this weekend.
That set includes lung and bone marrow chips from the Children’s Hospital of Philadelphia and University of Pennsylvania, kidney chips from the University of Washington, bone and cartilage chips from MIT and chips modeling the blood-brain barrier from the biotech company Emulate. The hope is these projects will speed up the development of treatments for osteoarthritis, kidney stones and other conditions.
The team on the space station will infect the lung and bone marrow chip with Pseudomonas aeruginosa, a bacterium associated with hospital-acquired diseases, said Lucie Low, Ph.D., the scientific program manager for the NIH's Tissue Chip for Drug Screening program.
"They will see how the bacterium affects lung tissues—because we know that the immune system changes up in space—and they will also be looking at how the bone marrow responds to that lung infection by the mobilization of neutrophils, which are white blood cells, in the bone marrow," she said.
The cartilage and bone chips will be modeling post-traumatic osteoarthritis in the knee joint.
"They will be looking at a lot of different kinds of 'omics' outcomes from the tissues when they are up in microgravity: proteomics, metabolomics, different kinds of cellular, molecular and metabolic changes in tissues that result from microgravity," Low said.
The kidney chip, meanwhile, will help with osteoarthritis research, as well as research into kidney stones.
"Astronauts seem to suffer from an increase in kidney stones and lose a lot of bone mass very rapidly when they enter microgravity," she said. "Because the kidney filters a lot of blood, an increased calcium concentration leached from the bones in microgravity turns up in the kidneys in the form of kidney stones.
The tissue chips are slated to hitch a ride from Cape Canaveral, Florida, this weekend—as part of a payload of more than 5,400 pounds that includes crew supplies, hardware and other scientific experiments. The launch was postponed twice this week due to technical issues, and is now scheduled for the early morning hours of Saturday.