Patch Helps Heart Grow New Cells

Rat study suggests a way of repairing lost cardiac tissue.

By Steven Reinberg
HealthDay Reporter
Monday, July 16, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

MONDAY, July 16 (HealthDay News) -- A special patch placed on a damaged area of the heart regenerates cardiac cells after heart attack and improves heart function, a new study finds.

Success with the patch in rats may lead the way to new methods of repairing damaged human hearts and possibly spare some patients the need for a heart transplant, according to researchers reporting in the July 15 online edition of Nature Medicine.

"Normally, adult human hearts do not regenerate because the heart doesn't make more cardiomyocytes (heart muscle cells) after injury," explained lead researcher Dr. Bernhard Kuhn, from the Department of Cardiology at Children's Hospital Boston. "It would be desirable to induce the heart to make new cardiomyocytes after injury."

To that end, Kuhn's team created a patch that contains a compound called periostin, which helps cardiomyocytes divide and multiply. "If you do that over a number of cycles, you do get an increase in cardiomyocytes," he said. "So, the cardiomyocytes you have lost are replaced."

Periostin is a natural component of tissue surrounding cells. It comes from the skin lying around bone and helps stimulate cells to divide.

During a heart attack, cardiac cells die from lack of blood and oxygen. This damage prevents the heart from working normally. Typically, lost or damaged cardiac tissue cannot regrow.

In their experiments, Kuhn's team made patches from a material called Gelfoam and soaked the patches with periostin. They placed the patches on the damaged heart muscle of rats in which they had induced a heart attack.

After 12 weeks, the rats treated with the periostin patch experienced a 16 percent improvement in their heart's cardiac pumping ability. They also had less scarring of heart tissue, a reduction in the size of the damaged area of the heart, and more blood vessels feeding the area. In contrast, rats that received a patch without periostin showed no change in their heart function.

The hearts of rats treated with periostin showed a 100-fold increase in the number of heart cells and an average of 6 million more heart cells, far outnumbering the amount of dying cells.