Duke researchers are on their way to discovering how to mend a broken heart—literally.
Although testing has only been conducted on mice, researchers say they may soon have a new way to repair cardiac damage, such as the damage done by a heart attack.
“The idea is to construct a cardiac patch, which could then be applied onto the injured surface of the heart,” said Nicolas Christoforou, a research associate in biomedical engineering who is one of several engineers working on the patch.
During a heart attack, a clot stops the flow of blood to the heart, damaging the heart muscle.
After a heart attack, it is possible to remove the clot and take medicine to help prevent another heart attack, but the heart will never function as it did before, Christoforou said.
“The damage done is damage done,” he said.
He added that over time, the weakened part of the heart will cause the muscle to overwork itself and could lead to heart failure.
Researchers are designing the heart patch to strengthen the heart and function in a similar manner to the original heart tissue, Christoforou said.
The cardiac patch was originally developed using embryonic stem cells, which can turn into most other types of cells if different genes are inserted, he said.
Embryonic stem cells, however, have recently been replaced by stem cells from skin, which function like embryonic stem cells, he noted. The development of these cells, called induced pluripotent stem cells, has made it easier and cheaper to get large amounts of cells and has also eliminated the ethical issue associated with embryonic stem cells.
Christoforou said the goal is to get these cells to function like the cells that make up cardiac tissue and then use them to build up the strength of the damaged heart.
Despite the progress of this new cell-based therapy, a patch for human hearts is still a long way off, said Wendy Bian, a fifth-year graduate student in biomedical engineering.
“The cardiac patch that we are currently testing on mice is working great,” said Nenad Bursac, assistant professor of biomedical engineering, who studies cardiac tissue development.
He said testing the patch on humans is more difficult for several reasons. It is more expensive to acquire human cells than mouse cells. Also, human cells are more fragile and proliferate more slowly, which makes the process slower than when dealing with mouse cells.
He added that there are many advantages to the new method for heart repair compared to the current method, in which cells are injected directly into the heart. In the current method, most of the injected cells do not survive and therefore are not useful for heart repair.
“A major advantage of the cardiac patch would be the survival of more cells, which leads to a greater improvement of heart function,” Bursac said.
He added that cells within the patch would be differentiated before entering the body, which also increases effectiveness.
Implanting the patch, however, would require open chest surgery, Bursac said.
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