New bioengineered solutions

A procedure that helps many patients afflicted by diseased coronary arteries is balloon angioplasty. In this procedure, performed about 400,000 times in the U.S. each year, doctors use a special, catheter-mounted balloon to re-open clogged arteries. But in as many as a fifth of cases, the artery clogs up again.

Elazer Edelman’s lab focuses on problems of the vasculature, and one of his goals is reducing the odds that arteries will close up after treatment. Edelman, a faculty member with the Harvard-MIT Division of Health Sciences and Technology (HST), and his associates are in effect seeking to provide damaged blood vessels with the benefits of a brand new internal lining.

Helen Nugent, a postdoctoral fellow in Edelman’s lab, notes that the vessels’ native lining, called the endothelium, helps block reproduction of the microscopic muscle cells in the vessels’ own walls. “It secretes compounds that regulate the growth and biology of these smooth muscle cells,” she notes. But angioplasty, along with coronary-artery bypass operations, can badly damage the lining, thus impairing the growth-control machinery.

“When that happens, the smooth muscle cells start to migrate and proliferate,” says Nugent. “That not only undoes the procedure’s benefits but can block the artery all the more.”

The researchers’ solution? Create new tissue made up of endothelial cells and wrap it around the vessels.

To grow the tissue, the researchers use a “scaffolding” of a sponge-like material that’s highly effective at fostering such growth if seeded with the right cells. Moreover, when implanted on an artery, notes Nugent, “it molds itself to the vessel’s shape.”

Preliminary tests show the implants do very well at reestablishing normal growth controls in the treated arteries. Human trials will be next, and Nugent’s looking forward to them. “I’m excited by the idea that one of our lab’s innovations might actually help alleviate human disease,” she says.

by Richard Anthony « Previous | Next »

On Topic: health science+technology