Stem Cell Patch Repairs Damaged Hearts

A newly identified human cardiac master stem cell is being used to artificially create a strip of ventricular heart muscle tissue that essentially works "like slapping a Band-Aid on the heart.”

Researchers at the Harvard Stem Cell Institute (HSCI, Boston, MA, USA) employed a two-colored fluorescent reporter system to isolate first and second heart field (FHF and SHF, respectively) progenitor cells from developing mouse embryos and embryonic stem cells; genome-wide profiling of coding and noncoding transcripts revealed the distinct molecular signatures of these progenitor populations. The researchers then identified a committed ventricular progenitor cell in lineage that was capable of limited in vitro expansion, differentiation, and assembly into functional ventricular muscle tissue, representing a combination of tissue engineering and stem cell biology. The committed ventricular progenitor cell was then grown into a patch of tissue on a thin layer of polymer film, using technology first developed for the manufacture of microelectronic components; once placed on the film, the cells reorganized themselves spontaneously to form a section of cardiac tissue. The created heart muscle tissue was implanted into mice where the ventricular muscle had died, and the dimensions of the piece of were controlled by limiting their growth into the heart. The researchers added that other questions would have to be answered before the stem cell technology could be put to medical use, such as how to create an appropriate blood supply for the grafted heart muscle tissue. The study was published online on October 15, 2009 in Science.

"What we would like to do now is find new ways to deliver a heart patch that is three-dimensional; for doing this in animals, I anticipate being able to do some version of this in the coming year,” said lead author Kenneth Chien, M.D., Ph.D., director of the Massachusetts General Center for Cardiovascular Research (CVRC, Boston, USA) and a member of the HSCI. "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.”

One possibility of the new technology is that the ventricular patch would be placed over the area of tissue damaged by a heart attack (much like a plaster), 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.

Related Links:
Harvard Stem Cell Institute
Massachusetts General Center for Cardiovascular Research