Pitt researchers’ work on bone growth heads to space
What do a dentist, a super glue, and the International Space Station have in common? Not much normally, but starting Tuesday, they’ll begin a journey together to answer questions lying deep within our bones.
Dr. Giuseppe Intini, Associate Professor of Periodontics and Preventive Dentistry at the University of Pittsburgh School of Dental Medicine, is a dentist whose research at the Center for Craniofacial Regeneration focuses on skeletal stem cells — the “master cells” of the skeletal system — and their ability to rebuild bone. This is one of the reasons RevBio, the Lowell, Mass.based maker of a novel bone adhesive called Tetranite, tapped him and his team to study how well the product stimulates stem cells to regenerate bone both here on Earth and in space.
The Pitt lab’s research is scheduled to launch Tuesday afternoon to be delivered to the space station as part of the SpaceX Commercial Resupply Services mission.
According to Dr. Intini, there are two separate but related aspects to this study. The first one focuses on how stem cells behave in the microgravity of space.
“Previous studies show that stem cells are somehow ‘locked up’ in space and cannot move forward,” he said, meaning they can’t differentiate into other cell types or aid in tissue regeneration. Scientists believe this is one reason for the
extreme bone loss astronauts have been found to experience after spending even a few months away from Earth’s gravity.
“But even more interesting,” he said, “based on our preliminary data, it looks like these stem cells are not only locked, it appears they may actually increase in number.”
Why microgravity would cause stem cells to replicate but not differentiate or restore tissue is unknown, but this study would first verify if Dr. Intini’s hypothesis — which he referred to as “non-functional rejuvenation” — is correct.
The second aspect of the study
has to do with Tetranite, a patented injectable biomaterial that adheres bone to bone, serving as a kind of bony super glue. Although not yet available commercially, the product has performed well in tests and studies, including a previous expedition to the ISS that analyzed the product’s effects on osteoblasts, large bone cells that group together to create the bone’s structure. That study found that Tetranite promoted osteoblastic differentiation, fostering bone development, even in the microgravity of space. Now, under the direction of Dr. Intini and his team, the company wanted to
see if the product also fos-ters bone development in skeletal stem cells by “unlocking” them in microgravity, allowing them to function normally.
Practical applications will be great for astronauts, who currently have to exercise up to three hours per day to limit the amount of bone loss while away from the strong pull of Earth’s gravity, but they don’t end there.
“Obviously, NASA is interested in developing technologies that are not only helpful to people that go to Mars,” Dr. Intini said. “They want to make sure we can improve our lives here on Earth as well.”
Osteoporosis is a bone disease that affects bone density, similar to the way microgravity acts on astronauts’ bones. According to the CDC, osteoporosis is the most common bone disease in the United States, affecting about 12.6% of adults over 50. Low bone mass, which occurs before osteoporosis, affects about 43.1% of adults over 50. When bone mass is leached from the body, so is the bone’s strength and structural integrity, leading to fractures and breaks. In a news release about the study, Brian Hess, the chief executive of RevBio, said: “The data generated from this experiment may one day help show that Tetranite is effective in treating bone fractures and stabilizing orthopedic implants in patients who suffer from osteoporosis.”
“It’s beautiful science,” Dr. Intini said a little wistfully.
He’s proud of his team, too, like a father watching his children soar to new heights, mentioning everyone by name: Dr. Xuehui Geng, Roberta Di Carlo, Ph.D., Luigi Mancinelli, Ph.D., and Dr. Taiana Campos Leite. “To my knowledge,” said Dr. Intini, also with pride, “this is the first bone biology study in which a dental school is involved in space.”
When asked if he was eager to see his team’s work launch on a rocket to the ISS National Laboratory, Dr. Intini laughed and said, “It’s just like any other research — I get excited about any kind of research!” His friends and family, on the other hand, seem to feel differently. “All my friends in Italy are talking about it and my kids have been telling this to the entire elementary school, you know.”
Then, with a smile, he admitted: “I’m very excited.”