Last Modified 10:38 AM, July 9, 2009

September 15, 2005—

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.
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.

"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."

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