"The ability of the superhealer mice to have superior healing after a fracture may go beyond the properties of their stem cells and be some beneficial factor, like a growth factor, that we don't know about yet," Guilak said.
The delivery of 10,000 typical or superhealer stem cells to the joint prevented the mice from developing PTA, unlike a control group that received only saline.
Diekman said the team looked at markers of inflammation and saw that the stem cells affected the inflammatory environment of the joint after fracture.
"The stem cells changed the levels of certain immune factors, called cytokines, and altered the bone healing response," said Diekman, who is also with the Duke Department of Biomedical Engineering.
Guilak said that very few studies have purified stem cells to the degree they were purified for this study. They used mesenchymal stem cells, which are bone marrow cells not destined to become part of blood.
Diekman said that one of the challenges in the field is isolating and developing a system for sorting the specific cells they wanted, the mesenchymal stem cells, which form a very rare cell type in the bone marrow.
"We found that by placing the stem cells into low-oxygen conditions, they would grow more rapidly in culture so that we could deliver enough of them to make a difference therapeutically," Diekman said.
|Contact: Mary Jane Gore|
Duke University Medical Center