Protecting Future Astronauts: Embry-Riddle Researchers Study Radiation Effects on Micro Human Organs

Researchers at Embry-Riddle Aeronautical University have designed and built a micro-scale brain, liver and gut system and exposed it to radiation to investigate the effects of one of the most dangerous health risks associated with space travel.

“Our research can use human cells, modifying them to develop various organ tissues, and model the organs’ response to radiation,” said Dr. Cassandra Juran, assistant professor of Human Factors and Behavioral Neurobiology and co-director of Embry-Riddle’s Space Physiology Antibody and Cellular Engineering Laboratory (SPACE Lab).

Space radiation can put astronauts at risk for radiation sickness associated with cell damage, especially affecting the gastrointestinal system, as well as increased incidence of cancer, central nervous system damage and degenerative disease.

The experiments will also support testing countermeasures to space radiation, such as pharmaceutical treatments, to maintain the health and well-being of future astronauts.

Juran said the brain, liver and gut were chosen because they are particularly sensitive to radiation, and because of their important roles and interactions in the human body. For instance, gut health has been shown to be extremely important to overall health, and data shows that a healthy gut and liver lead to a healthier brain, she said.

Exposing Organoids to Radiation Yields Results

The Embry-Riddle team’s working brain-liver-gut system, which is about the size of a thumb drive, starts with human pluripotent stem cells. The stem cells, when given chemical activators, can form tissues that function like specific organs in the human body. In this experiment, the tissues function like the brain, liver and intestines.

The lab-grown tissues, called organoids, are then incorporated into a “tissue chip,” or a miniature, engineered cell system in which they grow and interconnect via a sort of circulatory system of fluid. The researchers can then subject the tissue chip to the levels and types of radiation encountered in space.

The team recently conducted tests on the multi-organ system at Brookhaven National Laboratory in New York, which is considered the premier institute in the United States for investigating a range of radiation and particle physics interactions. At Brookhaven’s NASA Space Radiation Laboratory, the researchers were able to model the radiation environments found in space.

“Basically, you can model the radiation environment associated with time on the International Space Station, a trip to the moon or Mars, or an estimation of any type of galactic travel,” Juran said.

The effects of the radiation on the microsystem will be compared to the effects of natural aging, which will be investigated over time. In its first experimental run earlier this month, the system functioned well and is already yielding novel results, Juran said.

For example, when the organoids were exposed to radiation separately, they showed similar degeneration. When they were linked as a three-organoid system, however, the gut organoid was most severely affected, with the liver and brain surviving better.

“These results suggest a possible redistribution of radiation stress across the linked organs, with the gut bearing the greatest injury burden,” said Juran, adding that this phenomenon probably occurs because the gut has more rapid cellular turnover and can recover more quickly once the damaging radiation is removed.

Further experimentation will take place in the fall.

Dominic Sandell, who earned his bachelor’s degree in Aerospace Physiology this year and will enter a master’s program at Vanderbilt University in Tennessee, said a main reason the project is important is that it not only demonstrates the effects of radiation on one organ, but also shows “how each system reacts in relation to the others.”