Gene-modified stem cells: the next generation therapy for complex bone fractures

As much as 20% of the 7.9 million fractures that are treated in the U.S. each year fail to heal, thus causing much disability and pain. State-of-the-art therapies that are currently being developed include the use of the patient’s own stem cells in order to speed up the healing process. Adult stem cells reside in the bone marrow and in other tissues, serving as the body’s reservoir for repair cells. Yet stem cells need to be triggered to take part in the repair of tissues. One of the attractive ways to do so is by activating specific genes in the stem cells that “force” them to act and repair. The process is called “genetic engineering,” but has so far been limited and complicated by the need to grow the cells in Petri dishes for a few weeks.

In the May 2011 issue of Molecular Therapy, Dr. Jay Lieberman and colleagues recently proposed an attractive and faster “same-day” approach to obtain genetically engineered stem cells. The researchers obtained a sample of stem cells from rat bone marrow and genetically engineered them using a special virus carrying a gene for bone formation. The cells were then immediately implanted into a bone defect. The researchers reported that the “same-day” cells efficiently repaired the bone defects. Moreover, they showed that the new method led to acceleration in the healing process and yielded higher quality of bone, compared to the bones treated with cells that were grown in Petri dishes.

The “same day” strategy proposed by Lieberman’s group holds great promise for the treatment of complex fractures and other conditions of bone loss due to trauma, cancer or birth defects.