April 4, 2011 (LifeSiteNews.com) – Researchers at the University of Minnesota used adult stem cells to create a living human heart that they hope will revolutionize transplants.
The breakthrough, said lead researcher Dr. Doris Taylor, could ultimately mean that “donated” hearts are no longer used in transplant operations, circumventing the ethical problems involved in organ donation and obviating the need for drugs to combat immune system rejection.
Dr. Taylor, director of the university’s Center for Cardiovascular Repair, is one of the world’s leaders in heart organ repair and regeneration and has said it is her goal to create a living heart that can be transplanted into a patient, entirely out of stem cells.
She presented her team’s findings at the American College of Cardiology’s annual conference in New Orleans.
“The hearts are growing, and we hope they will show signs of beating within the next weeks,” she told the Daily Mail. “There are many hurdles to overcome to generate a fully functioning heart, but my prediction is that it may one day be possible to grow entire organs for transplant.”
The breakthrough is a follow-up on work Dr. Taylor completed in 2008 in which her team used stem cells to rebuild the hearts of rats. They removed all the muscle cells in a rat heart, leaving just a “scaffold” of other tissues such as blood vessels and valves. This scaffold was then repopulated with stem cells, which took their cues from the scaffold tissue to regenerate healthy, functioning heart muscle.
The latest step in Dr. Taylor’s research took that theme one step further and removed the muscle cells from a heart obtained from a human donor, regrowing the muscle using stem cells taken from a second person. The researchers say that a heart taken from a pig may also be suitable.
The muscle cells are removed using detergents, leaving an extracellular matrix or “skeleton.” The stem cells used this skeleton to grow millions of new heart cells and create heart muscle tissue.
“We are a long way off creating a heart for transplant, but we think we’ve opened a door to building any organ for human transplant,” she said.
A similar technique was used in March last year to create a new trachea for a ten year-old boy.
In related news, a team of researchers at the University of Miami has shown that damaged heart tissue can be repaired by injecting the patient’s own stem cells directly into the heart. In the experiment, published in the March edition of the Journal of the American College of Cardiology, donated stem cells were injected into the hearts of eight male volunteers who suffer from chronically enlarged, low-functioning hearts. The Miami researchers have already documented a significant reduction in size, scar tissue, and a notable improvement in heart function.
The creation of whole working organs for transplant is the “Holy Grail” of stem cell research. Stem cells that have been used in this research and in some current disease treatments have been taken from patients’ skin, bone marrow, fat, teeth and blood.