Unbelievably
they have actually done it. They have
been able to restore failed heart tissue with new tissue in a substantial
manner. This was one of the original
dreams when stem cells were first recognized three decades ago. Now we are seeing real delivery.
The next
decade will see the full advent of therapeutic tissue replacement become
standard. It will also see teeth
replacement and bone replacement as well.
That is not a lot of time.
As usual it is understated, but real progress
has been far swifter than expected and time frames appear to represent the
maximum needed these days.
Human
stem cells used to repair damaged monkey hearts
By Nick Lavars
May 2, 2014
In what could mark a significant
breakthrough in the treatment of heart disease, researchers at the University
of Washington (UW) have successfully repaired damaged tissue in monkey hearts
using cells created from human embryonic stem cells. The findings demonstrate
an ability to produce these cells on an unprecedented scale and hold great
potential for restoring functionally of damaged human hearts.
The researchers were exploring ways of
restoring human hearts damaged by myocardial infarctions, a common type of
heart attack that blocks major arteries and prevents oxygen from reaching the
heart muscle. This lack of oxygen in turn causes damage to the muscle tissue
and impacts the ability of the heart to pump blood. The researchers are aiming
to restore these hearts to full functionality using cells grown from human
embryonic stem cells.
"Before this study, it was not known
if it is possible to produce sufficient numbers of these cells and successfully
use them to remuscularize damaged hearts in a large animal whose heart size and
physiology is similar to that of the human heart," says Dr. Charles Murry,
professor of pathology, bioengineering and medicine at UW and leader of the
research team.
In testing the approach, the researchers
anesthetized pigtail macaques and induced controlled myocardial infarctions
lasting for 90 minutes apiece, an established model for studying myocardial
infarctions. Two weeks later, the scientists injected one billion heart muscle
cells into the damaged muscle, ten times the amount researchers had previously
been able to generate.
Over the following weeks, the injected
cells infiltrated the damaged tissue, maturing to form new muscle fibers and
beat in synchrony with the heart. Three months after the injections, the
cells appeared fully integrated with the original tissue.
"The results show we can now produce
the number of cells needed for human therapy and get formation of new heart
muscle on a scale that is relevant to improving the function of the human
heart,” says Dr. Michael Laflamme, UW assistant professor of pathology.
The researchers say that the injected
stem cells regenerated 40 percent of the damaged heart tissue, though some
side effects were observed. In the first weeks after the injections, the team reported
occurrences of irregular heartbeats, also known as arrhythmias. However, the
problem subsided after two to three weeks once the cells had matured and become
stable.
From here, the researchers will work to
reduce the risk of arrhythmias and also to clearly demonstrate that the cells
are capable of substantially improving the functionality of a damaged heart.
They are hopeful the approach will be ready for clinical trials in humans
within four years.
The team's research was published in the
journal Nature.
Nick was born outside of Melbourne,
Australia, with a general curiosity that has drawn him to some distant (and
very cold) places. Somewhere between enduring a winter in the Canadian Rockies
and trekking through Chilean Patagonia, he graduated from university and
pursued a career in journalism. He now writes for Gizmag, excited by tech and
all forms of innovation, Melbourne's bizarre weather and curried egg
sandwiches.
No comments:
Post a Comment