Bones that refuse to heal may one day be set straight by a drug that stimulates the growth of new blood vessels, according to new research from the University of California, San Francisco. So far, however, the growth factor drug has been tested only in mice, and it could be years before it is used in hospitals.
These results were presented at this week's annual meeting of the Orthopaedic Research Society, in Orlando, Florida.
As cancer and cardiology researchers already know, VEGF, or vascular endothelial growth factor, promotes blood vessel growth. Oncologists at a few biotech companies are running clinical trials of anti-VEGF drugs to reduce the flow of blood to tumors. Cardiologists are studying whether VEGF can sprout new blood vessels to bypass blocked arteries in patients with inoperable heart disease.
Blood vessel growth, known as angiogenesis, is also thought to help deliver the chemicals needed for bone cells to rebuild after a fracture, says Jill Helms, PhD, DDS, assistant professor of orthopedic surgery at UCSF. "Vascular invasion is one of the critical steps of bone repair," said Helms, who collaborated with Zena Werb, PhD, a professor of anatomy at UCSF.
While most broken bones will repair to their original strength within a matter of weeks, some breaks stubbornly refuse to heal for months, years, or longer, she said. Scientists have suggested a few factors that may interfere with bone healing, such as nutrition, illnesses such as diabetes, and damage to soft tissue surrounding the bone. Helms and her colleagues suspected that soft tissue damage interrupts proper blood flow to the fracture, and that proteins that encourage angiogenesis, such as VEGF, might help to heal these stubborn breaks.
To test VEGF as a possible treatment, Helms' team worked with 20 mice with
broken limbs that were being treated with pain-relieving drugs. After
splinting the legs of these mice, the researchers sh
Contact: Kevin Boyd
University of California - San Francisco