One of the major health risks for astronauts may have a cure on the way. A specially-formulated medical compound has been shown to prevent bone loss in mice, and perhaps humans, aboard the International Space Station (ISS).
A team from the University of California Los Angeles (UCLA) and the Forsyth Institute in Cambridge, Massachusetts, is researching solutions to the problem. Microgravity causes a one percent drop in bone mineral density (BMD) per month in the ISS. To ameliorate that loss, they turned to 30-year-old discovery and earlier research to develop a new drug that they claim not only prevented bone loss in the ISS' rodent residents, but even increased bone density.
Dr. Chia Soo is a UCLA professor of plastic and reconstructive surgery. She recently said, “Our findings hold tremendous promise for the future of space exploration, particularly for missions involving extended stays in microgravity.”
The drug they developed in the experiment was a modified version of NELL-1 which is a protein that is used to regulate bone growth. NELL-1 was discovered by UCLA chair of orthodontics Dr Kang Ting in 1996. He found it was associated with a birth defect involving overactive bone growth. A 2015 study by Ting and other researchers, including Dr. Soo, found that NELL-1 was effective in stimulating bone growth both in stem cells in lab environments and animals.
For this latest study, a specific version of NELL-1 was necessary to simplify the treatment process. The researchers developed a form of NELL-1 that was bound to bisphosphate called BP-NELL-PEG that “specifically targets bone tissues without the common deleterious effects of [biphosphate],” and it appears to have been a resounding success.
Mice who spent nine weeks aboard the ISS and were given BP-NELL-PEG “showed a significantly increased BMD in all bones compared to control,” the team said in their paper. Both the mice on the ground and on the ISS who were treated with the experimental medication showed increased BMD, as one may expect from prior NELL-1 experiments.
The researchers said that “We conclude that BP-NELL-PEG successfully reverses osteoporitic bone loss and is a viable pharmacologic countermeasure for use in spaceflight”.
Soo told UCLA that the next step in the study was the analysis of live animal data, and how it relates to humans since mice are not prime targets for interplanetary travel.
Soo added that “We hope this will provide some insight on how to help future astronauts recover from longer duration space missions. That doesn't answer the most pressing question about this discovery, though: When can we expect human trials of what could be a life-changing treatment for astronauts, much less those suffering from bone density diseases?”
Burlington, Massachusetts-based Bone Biologics is the only company that appears to have reached the point of doing human clinical trials using NELL-1 to treat degenerative disk disease in a pilot program in Australia. It's unclear what the status of that study is. It was first announced in 2019 and the company said again in April of this year that it was still working on starting the same 30-person study.
It is unclear when human trials of any NELL-1 treatment could begin. Astronauts will probably be forced to maintain regular treadmill sessions for the foreseeable future.
So far, there has been no word on when treatment for brain changes and other detrimental health effects of space exposure will be any closer to being addressed.