Study moves scientists 1 step closer to
creating youthful heart patches from old cells
 |
This is an image of an aged stem cell
after growth factors were added.
Credit: Faculty of Medicine,
University of Toronto
|
A
new method of growing cardiac tissue is teaching old stem cells new
tricks. The discovery, which transforms aged stem cells into cells
that function like much younger ones, may one day enable scientists
to grow cardiac patches for damaged or diseased hearts from a
patient's own stem cells—no matter what age the patient—while
avoiding the threat of rejection.
One method of avoiding the risk of
rejection has been to use cells derived from a patient's own body.
But until now, clinical trials of this kind of therapy using elderly
patients' own cells have not been a viable option, since aged cells
tend not to function as well as cells from young patients.
"If you want to treat these people
with their own cells, how do you do this?"
It's a problem that Radisic and her
co-researcher, Dr. Ren-Ke Li, think they might have an answer for: by
creating the conditions for a 'fountain of youth' reaction within a
tissue culture.
Li holds the Canada Research Chair in
Cardiac Regeneration and is a Professor in the Division of
Cardiovascular Surgery, cross-appointed to IBBME. He is also a Senior
Scientist at the Toronto General Research Institute.
Radisic and Li first create a
"micro-environment" that allows heart tissue to grow, with
stem cells donated from elderly patients at the Toronto General
Hospital.
The cell cultures are then infused with
a combination of growth factors—common factors that cause blood
vessel growth and cell proliferation—positioned in such a way
within the porous scaffolding that the cells are able to be
stimulated by these factors.
Dr. Li and his team then tracked the
molecular changes in the tissue patch cells. "We saw certain
aging factors turned off," states Li, citing the levels of two
molecules in particular, p16 and RGN, which effectively turned back
the clock in the cells, returning them to robust and healthy states.
"It's very exciting research,"
says Radisic, who was named one of the top innovators under 35 by MIT
in 2008 and winner of the 2012 Young Engineers Canada award.
Li and Radisic hope to continue their
goal to create the most effective environment in which cells from
older patients can be given new life. "We can create much better
tissues which can then be used to repair defects such as aneurysms,"
Li says, as well as repairing damage caused by heart attacks.
The study was recently released in
the Journal of the American College of Cardiology, the top
journal in the field of cardiovascular medicine.
About IBBME
The Institute of Biomaterials and
Biomedical Engineering (IBBME) is an interdisciplinary unit situated
between three Faculties at the University of Toronto: Applied Science
and Engineering, Dentistry and Medicine. The Institute pursues
research in four areas: neural, sensory systems and rehabilitation
engineering; biomaterials, tissue engineering and regenerative
medicine; molecular imaging and biomedical nanotechnology; medical
devices and clinical technologies.
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