More than
half a million people die in the United States from heart failure each
year, thousands of them while awaiting a transplant. But with the
release of a new scientific paper comes a potential solution to the
deficiency: growing new ones.
That’s
exactly what a team of researchers at Massachusetts General Hospital’s
Center for Regenerative Medicine (CRM) set out to do. Their work, published this week in the journal Circulation Research, proves
the idea has the potential to be a game changer. Using skin cells
reprogrammed into stem cells, the researchers were able to generate
functional heart tissue.
The
process would not only eliminate the need for perfect match donors, but
it would dramatically reduce the chance of immunorejection. Considering
that an estimated 22 people die per day awaiting an organ, the implications could be huge.
Led
by Dr. Harold C. Ott, assistant professor of Surgery at Harvard Medical
School, the team built on previous studies in rats. In order to
generate a new heart, researchers need what’s called a scaffold to give
it shape. Growing this part of the heart, which is made up of proteins,
is lengthy and difficult.
To
bypass this step, the researchers used 75 hearts from the New England
Organ Bank. All of the hearts were deemed unfit for transplantation, the
deceased either brain dead or having suffered cardiac arrest. Through
these hearts, the team was able to use a “detergent” that strips it of
remaining living cells. Once these components were gone, the researchers
were left with a perfect scaffold to seed the new cells.
source : thedailybeast.com
The final
step, called genetic manipulation, involved reprogramming skin cells
(using RNA) into stem cells and injecting them into the heart to
simulate the real environment.
"Generating functional cardiac tissue involves meeting several challenges," said
Dr. Jacques Guyette, one of the study’s lead researchers. "These
include providing a structural scaffold that is able to support cardiac
function, a supply of specialized cardiac cells, and a supportive
environment in which cells can repopulate the scaffold to form mature
tissue capable of handling complex cardiac functions."
The
CRM team’s report is notable not just for its success in generating
stem cell-derived heart tissue, but because it was the first to analyze
the remaining scaffold of the heart after decellularization. For Ott,
the success of the experiment is an “important step towards novel device
engineering strategies” that could potentially “enable patient-specific
disease modeling and therapeutic discovery.”
As
exciting as the endeavor is, Ott and his team aren’t the only ones
making strides. Researchers at the University of Toronto Canada recently announced
that they had successfully grown heart cells around a skin suture,
creating a 3D model of the heart that functions like the real thing. The
discovery could be hugely beneficial for testing out new drugs and,
could eventually substitute for real organ transplants.
Guyette
and Ott, like the U of T team, have their eyes set on generating an
intact and viable heart as well—a scenario that Guyette concedes is not
yet within reach. “Regenerating a whole heart is most certainly a
long-term goal that is several years away, so we are currently working
on engineering a functional myocardial patch that could replace cardiac
tissue damaged due a heart attack or heart failure," he said.
“Our team is excited to further develop both of these strategies in future projects,” added Ott. For the 5.1 million
people in the United States with heart failure—half of whom will die
within five years of their diagnosis—the new developments can’t come
soon enough.
source : thedailybeast.com
