Stem Cells Grow Heart Tissue in Lab

Oct. 16 -- THURSDAY, Oct. 15 (HealthDay News) -- Researchers report a major step toward the goal of literally rebuilding a broken heart -- creating a strip of working heart muscle in the laboratory by using a newly identified human cardiac master stem cell.

"This work moves us closer to heart stem cell therapy," said Dr. Kenneth Chien, director of the Massachusetts General Center for Cardiovascular Research, a member of the Harvard Stem Cell Institute and leader of a group reporting the work online Oct. 15 in Science.

That therapy, he said, would be "almost like slapping a Band-Aid on the heart."

One possibility is that a thin layer of muscle cells of the ventricles, the heart chambers that pump blood to the body, would be placed over the area of tissue damaged by a heart attack, where it would expand and grow into working heart muscle. Another is that the cells would be injected into the damaged area, with the hope that they would grow to form healthy new tissue.

"For doing this in animals, I anticipate being able to do some version of this in the coming year," Chien said. "Talking clinically, I believe that in five years or so the groundwork would be laid for very early clinical studies to deliver these cells to humans."

A key discovery was identifying the specific stem cells used to produce the strip of heart muscle, Chien said. Those cells were identified in humans just two months ago, the latest step in a series of discoveries, first in mice and then in humans, that, among other things, determined that a completely different stem cells gives rise to the left side of the heart, where most disease occurs, he said.

Once those cells were identified, a technique developed in the laboratory of Kevin Kit Parker, an associate professor of applied science at Harvard's School of Engineering and Applied Sciences, was used to grow the strip of heart muscle.

The cells are grown on a thin layer of polymer film, he said, with the same technology used to form the microelectronic components found in cell phones and other advanced gadgets.