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
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.
From 1992 to 2001, Dr. LeGeros was the principal investigator and
the director of a $6.55 million NIDCR grant, which established the
Northeast Minority Oral Health Research Center at NYU. The grant
was conducted in collaboration with The Forsyth Institute in Boston.