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Medical Research Developing Proteins that Mimic Natural Tissue

A development in tissue repair is giving doctors an alternative way to repair and replace damaged tissues in the body.

At the Oregon Medical Laser Center in the western city of Portland, a team of scientists is working on building tissue from proteins found in the human body. Led by cardiologist Kenton Gregory, the researchers are creating biocompatible tissues made of a substance called elastin, a protein that is produced naturally in the body.

"It's a new field called 'bio-mimicry', where you mimic Mother Nature tissue engineering, and that's just evolved in the last few years," said Dr. Gregory.

One of the areas where Dr. Gregory hopes to use elastin is in the heart. He wants to replace metal stents, which are wire mesh tubes used to unblock arteries, with stents made from elastin.

Cardiologist Doctor David Roberts of the Sutter Institute in California, has used metal stents in his patients, and thinks they can be improved upon.

"The problem with stents is that they tend to scar along the inside after you put them in,” said Dr. Roberts. “So as high as one out of three, to one out of four, will plug back up."

Since elastin is made of human DNA, Dr. Gregory thinks the probability of the body rejecting elastin-coated stents, over metal or plastic, is lower.

"Synthetic molecules, they're are almost always rejected by the body to some degree, because the body's immune system recognizes those items as foreign, and tries to reject them or destroy them." Dr. Gregory said.

With a $6 million dollar grant from the U.S. Army, the Portland laboratory is studying elastin and other substances as tools for army medics on the battlefield.

One of the products they developed is a patch made from chitosan, which is a fiber extracted from the shells of crustaceans, like shrimp and crabs. The bandage stops serious bleeding by fusing itself directly to a wound, and it is currently used on soldiers in Iraq and Afghanistan.

Dr. Gregory and his team hope to develop elastin tissue for all kinds of replacements: skin, stomachs, intestines, arteries and eventually entire body parts.

Medical experts say the only possible negative repercussion of using laboratory-produced elastin to repair tissue, is that it could cause inflammation or calcification.