Transplantation of adult stem cells help mend bone fractures

An animal study has shown that transplantation of adult stem cells, enriched with a bone-regenerating hormone, can help mend bone fractures that are not healing properly.

Anna Spagnoli, MD, associate professor of paediatrics and biomedical engineering led researchers at the University of North Carolina at Chapel Hill School of Medicine.

They demonstrated that stem cells manufactured with the regenerative hormone insulin-like growth factor (IGF-I) become bone cells and also help the cells within broken bones repair the fracture, thereby speeding the healing.

"This problem is even more serious in children with osteogenesis imperfecta, or brittle bone disease, and in elderly adults with osteoporosis, because their fragile bones can easily and repeatedly break, and bone graft surgical treatment is often not successful or feasible," Spagnoli said.

Fractures that do not mend within the normal timeframe are called non-union fractures.

Using an animal model of a non-union fracture, a "knockout" mouse that lacks the ability to heal broken bones, Spagnoli and her colleagues studied the effects of transplanting adult stem cells enriched with IGF-I.

"We found that stem cells empowered with IGF-I restored the formation of new bone in a mouse lacking the ability to repair broken bones," she said.

"This is the first evidence that stem cell therapy can address a deficiency of fracture repair," she stated.

This success in an animal model of fracture non-union, Spagnoli said, " It is a crucial step towards developing a stem cell-based treatment for patients with fracture non-unions."

IGF-I is currently approved for treatment of children with a deficiency of this hormone, causing growth failure.