UC Davis clinical trial helps bones heal

For Diana Souza, working on her 23-acre ranch in the mountains east of Redding, California is a labor of love. But last year, a fall from a ladder left her with a badly fractured left arm that would not heal. Her arm became deformed from the cumulative effects of that fall and two previous fractures and several surgeries and Souza was faced with the real possibility of having only one working arm.

Souza told the story of the clinical trial at UC Davis that returned strength to her arm at the CIRM governing board’s Spotlight on Disease seminar on March 21st in Sacramento. Videos from these talks are now available on our website. She attributed her positive outcome to her orthopedic surgeon, Dr. Mark Lee, an associate professor of surgery at the UC Davis School of Medicine, who led the clinical trial. He’s testing a way of using stem cells from a patient’s bone marrow to help heal difficult fractures:

It was his clinical research using stem cells that I think made the biggest difference in my case. I still had to undergo a lengthy surgery and somewhat painful recovery but he could not have accomplished nearly as much and help enable my weak and unhealthy bones to repair themselves without using the stem cells he extracted from my bone marrow to fill in the holes and gaps in my bone which strengthen the bone and finally allowed my arm to heal properly and look normal.

Souza’s story of a hard-to-heal fracture isn’t an isolated incident. Everyday Dr. Lee sees victims of high-energy trauma such as car accidents. In these cases, severe bone fractures can lead to such massive bone loss that realigning and fixing the bone with metal implants is not enough to heal the bone. Dr. Lee, who also spoke at the Spotlight, explained the problem further as he showed images of severe fractures:

What you can see here is a massive area of missing bone. I think it’s important to realize that this is an area that will not heal without help. It’s a problem we don’t have great solutions for at this point in time.

The current gold standard treatment for these fractures involves taking healthy bone from one part of the body and implanting it at the fracture site. Although the method can be effective it has many drawbacks including the limited amount of bone graft, a slow healing time and an overall low reliability. In the clinical trial that healed Souza's arm, Lee isolated mesenchymal stem cells from her bone marrow and transplanted them into the site of her fracture. These cells have the ability to transform into osteoblasts, the bone-forming cells of the body. They also release proteins that help support bone repair and formation.

While Lee continues to optimize methods for harvesting mesenchymal stem cells, his colleague, Dr. Kent Leach, a biomedical engineer at the UC Davis College of Engineering, who also spoke at the meeting, is using these cells to discover better ways of growing new bone. He designs scaffolds that would ultimately be transplanted along with the stem cells to provide a temporary structure during the bone healing process. During the Spotlight seminar, Leach said that tweaking the composition of these scaffolds can significantly increase the ability of the stem cells to nurture the growth of new bone.

The hope at UC Davis is that these collaborative efforts between clinical researchers and biomedical engineers, not to mention veterinary researchers, will accelerate the path to new stem cell therapies. In her introduction to the talks, Claire Pomeroy, a CIRM governing board member and vice chancellor of UC Davis human health sciences, pointed out that this collaboration would not have been possible without CIRM support.

I would like to emphasize that all of these researchers work with the team at the UC Davis Good Manufacturing Practice facility located in the CIRM-supported Institute for Regenerative Cures [watch our video about that facility here]. That’s where these cells are being prepared in the safest and most efficient manner. With this collaboration and with support from CIRM, UC Davis is uniquely positioned, I believe, to move regenerative medicine from the basic science of biomedical engineering through small and large animal models at our veterinary school to human clinical trials at our medical center.

Diana Souza certainly can attest to some early success of these researchers’ efforts:

I’m healing. I’m healing quite well. My friends cannot believe the difference in my physical strength and well-being. And I cannot believe the difference. It’s incredible.

T.D.