The National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health (NIH) has awarded the NYU College of Dentistry a four-year grant in the amount of $1.99 million to develop biomaterials that promote bone formation and inhibit bone loss in osteoporosis. The grant’s principal investigator is Dr. Racquel Z. LeGeros, Professor of Biomaterials and Biomimetics and the Leonard I. Linkow Professor of Implant Dentistry.

Osteoporosis is characterized by brittle bones, and occurs when the rate of bone loss becomes much greater than the bone formation rate. It’s estimated that 80 percent of osteoporosis cases occur in women, particularly after menopause, and that a woman’s risk of hip fracture from osteoporosis is equal to her combined risk of breast, uterine, and ovarian cancer. As the industrialized world’s population ages, the number of hip fractures due to osteoporosis is projected to rise worldwide to 6.3 million by 2050, from 1.7 million in 1990. In the United States, where an estimated 10 million Americans suffer from osteoporosis, the disease is responsible for more than 1.5 million fractures a year.

Although some osteoporosis treatments can reduce the rate of bone loss, these have not been shown to be very effective in rebuilding bone that has already been lost. Many treatments also have serious side effects. For example, supplements of estrogen, a hormone that dwindles at menopause, can prevent bone loss, but may slightly increase the risk of breast cancer. Last fall, a group of researchers recommended that estrogen not be prescribed solely to treat or prevent osteoporosis because of this risk.

Dr. LeGeros’s research aims to develop novel materials from three ions that have separately been associated with bone formation, biomineralization, and the management of bone loss. “We will combine the three ions — magnesium, zinc, and fluoride — in a calcium phosphate matrix,” she said. “Then we will see if these biomaterials affect the strength, density, quality, and composition of bones in rats with induced osteoporosis.”

Although Dr. LeGeros has researched calcium phosphate-based materials for bone repair before, this is the first time that she has headed a study on osteoporosis. Her previous major research has focused on calcium phosphates associated with normal and pathological calcification, and on calcium phosphate coatings for orthopedic and dental implants.