Penn Vet Working Toward A Bone-Mending Breakthrough

Penn Vet researchers closing in on tissue regeneration technology for horses - and humans

Published on: May 13, 2013

Much of today's nutritional and medical care for humans was first learned via animal husbandry and medicine. So it's no surprise that equine orthopedic research at University of Pennsylvania's School of Veterinary Medicine may soon speed bone and tissue regeneration in horses, dogs and humans.

It wasn't until the untimely loss of legendary thoroughbred Barbaro, the 2005 Kentucky Derby winner and hands-down Triple Crown favorite, that laminitis drew international attention. Since then, Penn Vet has zeroed in on research and discovery of ways to speed recovery after injuries.

Bone, cartilage, ligament, and tendon injuries are very common in human and animal patients, reports Dr. Kurt Hankenson, a Penn Vet researcher leading cross-species orthopedic team research on regenerative medicine. They're exploring multiple therapeutic approaches for regenerating bone, cartilage, tendons and ligaments.

FROM LAB TO LEG: Hankenson and collaborators are closing in on regenerative therapy to rebuild bones and tissues in animals and humans. Photo courtesy of Penn Vet
FROM LAB TO LEG: Hankenson and collaborators are closing in on regenerative therapy to rebuild bones and tissues in animals and humans. Photo courtesy of Penn Vet

Hankenson's work focuses specifically on using adult mesenchymal stem cells from the patient. By harvesting, culturing, expanding the patient's own MSCs, then delivering them directly back to the patient,

"we're able to better answer questions about the biology of bone formation and regeneration," explains the veterinary researcher. "These MSCs more accurately mimic [in-the-body] biology."

Hankenson was recently appointed the Dean W. Richardson Professorship in Equine Disease Research. He and Penn Vet are also leading in a much larger project funded by the Department of Defense, the Osteosynthesis and Trauma Care Foundation and the National Institutes of Health. With collaborators from Penn's School of Engineering and Applied Science, the Perelman School of Medicine, and the Children's Hospital of Philadelphia, he's exploring how Notch signaling regulates bone regeneration.

In brief, Notch signaling helps neighboring stem cells communicate with each other and assume their developmental role in regenerating bone or tissues. It's a key part of a multi-pronged regenerative therapy being developed.


Accelerate healing?
With MSC and notch signaling, can bone and tissue healing be accelerated?

"That's a great question," responds Hankenson. "We don't yet have a good sense of what the acceleration possibility is with this therapy.

"Biological systems have temporal limitations. Likely, it can only go so fast. This therapy may be best for clinical situations where healing is compromised because of missing bone or [loss of blood vessels to tissue]."

But Hankenson believes it could accelerate healing. While Penn's work with Notch signaling is largely in vitro, "we have [mouse model] studies supporting its role in promoting bone formation. But we're still some years away from viable clinical therapy."

Would it have helped Barbaro? "Remember, he had severe compound fracture of his lower leg. His bones were healing well. "But," replies the researcher, "he succumbed to contralateral limb overload laminitis. If we can promote more robust healing of fractured bones by using a biological therapeutic, we could perhaps prevent that laminitis."

Hankenson and a former student, Dr. Mike Dishowitz, have formed a start-up biotechnology company that's developing this therapy for human and animal applications.