Mending Broken Hearts
Reported October 13, 2009
(Ivanhoe Newswire) — Bioengineers at Duke University believe they have taken an important first step toward growing a living “heart patch” to repair heart tissue damaged by disease.
In experiments using mouse embryonic stem cells, the researchers created a mold to form a three-dimensional patch made up of heart muscle cells, known as cardiomyocytes. The new tissue exhibited the two most important attributes of heart muscle cells — the ability to contract and to conduct electrical impulses. The mold looks a lot like a piece of Chex cereal.
Researchers grew the cells in an environment similar to natural tissues. They encapsulated the cells within a gel made up of the blood-clotting protein fibrin, which provided mechanical support to the cells, allowing them to form a three-dimensional structure. They also found that the cardiomyocytes flourished only in the presence of another class of cells known as cardiac fibroblasts, which make up 60 percent of all cells present in the human heart.
“We found that adding cardiac fibroblasts to the growing cardiomyocytes created a nourishing environment that stimulated the cells to grow as if they were in a developing heart,” Brain Liau, graduate student in biomedical engineering at Duke’s Pratt School of Engineering was quoted as saying.
“When we tested the patch, we found that because the cells aligned themselves in the same direction, they were able to contract like native cells. They were also able to carry the electrical signals that make cardiomyocytes function in a coordinated fashion,” said Liau.
Researchers say more work is needed before humans can receive the patches. Next they plan to test their model using non-embryonic stem cells.
SOURCE: Annual Scientific Sessions of the Biomedical Engineering Society, Pittsburgh, PA, 2009