Washington, June 17 : A new study in mice by researchers at the University of North Carolina has shown that adult stem cells improve the healing of broken bones.
The study also showed that adult stem cells could eventually serve as a new treatment for the 10 to 20 percent of fractures that fail to heal.
"Lack of fracture repair often leads to several surgeries, long periods of immobilization, pain, bone deformities, and sometimes death," said the study's senior investigator, Anna Spagnoli, MD, of the University of North Carolina.
"The precise reason why a patient's fracture does not heal remains unknown in most cases," she added.
According to researchers, a key reason for bone union failure may be a deficiency in adult stem cells, which normally become reparative cells in response to damage.
Spagnoli said that stem cells in human bone marrow, called mesenchymal stem cells, could become bone, cartilage, fat, muscle, and blood vessel cells.
Directing these stem cells into the repair mode is one of the objectives of a new branch of medicine called regenerative medicine.
Spagnoli said that these adult stem cells, which can be obtained from a patient's bone marrow in a minimally invasive procedure, have been reported to improve fracture healing in a few patients.
However, animal studies are required before clinical trials can begin.
Spagnoli and her colleagues, therefore, performed a study in mice with leg fractures.
They took adult stem cells from the bone marrow of mice and engineered the cells to express a potent bone regenerator, insulin-like growth factor 1 (IGF-1).
Then they transplanted the treated cells into mice with a fracture of the tibia, the long bone of the leg.
Using computed tomography (CT or CAT) scanning, they showed that the treated mice had better fracture healing than did untreated controls.
Researchers found that the stem cells migrated to the fracture site and increased the bone and cartilage that bridged the bone gap.
"Our study provided critical data needed to implement a novel therapeutic approach in patients with impaired fracture healing," Spagnoli said.
She added that if scientists can duplicate the results of this animal study in humans, it might lead to a way to help those who suffer fractures that do not heal properly.
The results will be presented Monday, June 16, at The Endocrine Society's 90th Annual Meeting in San Francisco.