Boffins have used conditions aboard the International Space Station (ISS) to try out treatments for posttraumatic osteoarthritis.

Alan Grodzinsky, who led the research, was initially inspired by the levels of early-onset osteoarthritis he'd seen in female athletes.

"Totally normal knee," he explained in the April 2024 issue of Upward, a publication devoted to the International Space Station (ISS) National Laboratory, "and all of a sudden, you have a joint injury, and within five or ten or 15 years, you develop full-blown osteoarthritis."

According to research, posttraumatic osteoarthritis (PTOA) affects around 20 percent of those 650 million people worldwide who have osteoarthritis, but there are no US Food and Drug Administration (FDA) approved drugs to treat it.

Studying how PTOA starts is tricky, with doctors tending to treat the symptoms rather than the cause. Delivering medication to the cartilage is also difficult.

The experiment onboard the ISS, sponsored by the ISS National Laboratory, involved a microphysiological system - also called a tissue chip - capable of mimicking the earliest events of PTOA's initiation. Researchers could then try different treatments to hinder or block the condition's progression.

According to Upward, the results have been striking, both in terms of the accuracy of the tissue chip in providing a joint model and in demonstrating the effectiveness of treatments.

"This opens up new possibilities for testing drugs and interventions for osteoarthritis and other joint disorders," said Grodzinsky. "It could also aid in developing preventative treatments."

The experiment worked by applying pressure to donor cartilage before launch to simulate an injury and then placing the tissues into cultures. The microfluidics system then delivered nutrients and, in some cases, drugs to the tissues to see how they reacted once onboard the ISS.

The experiment was launched as a payload on the SpaceX CRS-17 mission in 2019, but problems with its microfluidics system meant the team had to try again in December 2020 with a payload launched on the CRS-21 mission.

Researchers found that the space-tested drugs appeared to lessen the impact of the injury, and the environment aboard the ISS seemed to enhance inflammatory responses in both the test tissues and the control group.

It is, however, difficult to translate what worked on the ISS into a treatment that might work on Earth. Despite the innovative tissue chip approach, the donor sample size - two - needs to be expanded.

Grodzinsky wondered if the findings were a "luck of the draw."

Upward asked: "Did the tissue from two donor knees used in the tissue chips sent to space happen to have this response, or would this happen to anyone's tissue?"

It's a good question since it is unlikely that sufferers will be launched to the ISS anytime soon.

Grodzinsky observed that, unlike experiments on Earth, "you can't just go back up to the space station a week or two later."

So, promising stuff, but, as is so often the case with such experiments, more research is needed. ®

https://www.theregister.com//2024/05/30/promising_results_for_osteoarthritis_treatments/