Engineering a Cure for Arthritis
It's
not the sort of statement you'd expect from a mechanical engineer. "We are looking at preventing
arthritis," says Tammy Donahue. While most of us think of
our health as the domain of medicine, Donahue applies principles from
solid and fluid mechanics classes to make a big difference in how we feel,
especially as we get older. Especially in our knees. For Donahue, an assistant
professor in the MEEM department, engineering is a great weapon in the
battle against osteoarthritis, the most common form of degenerative joint
disease. "It's a condition that's
mechanically induced," she explains. "As engineers, we're ideally
suited to understand the process." And the better the process
is understood, the better we can prevent it or develop drugs to combat
it, she hopes. Working with Eric Blough,
a visiting assistant professor of biology, Donahue is undertaking experiments
to determine just what happens as our knees wear out. Human knees are
hard to come by, so she uses cow knees provided by a downstate packing
plant. "Basically, we smack
the heck out of these knees, simulating running across a field, and see
what happens biochemically in the lab," she says. The focus of their work is
the meniscus, a disc of cartilage in the center of the knee joint. Like
all cartilage, it is about 70 percent water held in a sponge-like matrix.
Under gentle or moderate pounding, as when you walk around the block,
the meniscus works like a hydraulic shock absorber, releasing liquid and
then absorbing it again. However, when the meniscus
takes a beating--basketball, soccer and tennis come to mind--the fluid
stays in the matrix. And instead of cushioning your knee, it pummels the
bone ends. "The meniscal cells don't like that," Donahue says. "Our long-term goal is
to stop these harmful biochemical reactions through the use of pharmaceuticals,"
Donahue said. In a second project, they
extract the meniscal cells and subject them to shear stress, running fluid
back and forth over them to simulate the action in a joint. The cells
release calcium, which has been shown to stimulate the production of the
cell-killing chemical nitric oxide. Nitric oxide has been linked to a
whole host of degenerative diseases, including arthritis. "It's going really well,"
Blough said. "It's a promising area of research. "It really helps to incorporate
an interdisciplinary approach," he added. "People from different
fields have different perspectives on the same problem. That can lead
to solutions you'd never imagine if you only looked at a problem one way." 8/21/02
The researchers are working on two related projects to better understand
what's actually going on. In one, they compress a disc of meniscus and
then measure what proteins are generated in response.
