From
now on, we will be mostly reporting the steady advent of successful protocols that can
be directly applied very soon. Here we
now know that we can install a scaffold and seed it safely with differentiated
stem cells to completely restore the bone.
In three years at most this will spring out of the lab and into current
practice.
Almost
every special tissue is now been tackled and with burgeoning success.
Thus we
can predict that the wheel chair will be largely obsolete except for the
terminally ill and those in recovery in about six years. This may seem aggressive, but the cost of
potentially able bodied men and women to society is clearly sufficient to
promote a crash program of restoration therapy.
It
will be very welcome.
Mice have been poked, prodded, injected and dissected in the
name of science. But there are limits to what mice can teach us – especially
when it comes to stem cell therapies. For the first time, researchers
have turned skin cells into bone in a creature more closely related to
humans: monkeys.
In a study published Thursday in the journal Cell
Reports, scientists report that
they regrew bone in 25 rhesus macaques using induced pluripotent stem
cells (iPSCs) taken from the creatures’ skin. Since macaques are more closely
related to humans, their discovery could help push stem cell therapies into
early clinical trials in humans.
While this is the good news, the bad news is that iPSCs can
also seed tumors in monkeys; however, the tumors grew at a far slower rate than
in previous studies in mice. This finding further emphasizes the key role
primates likely will play in testing the safety of potential stem cell
therapies.
Repairing Bone
Researchers used a common procedure to reprogram macaque skin
cells, and coaxed them into pluripotent cells that were capable of building
bone. They seeded these cells into ceramic scaffolds, which are already used
by surgeons used to reconstruct bone. The cells took, and the monkeys
successfully grew new bone.
In some experiments, the monkeys formed teratomas – nasty tumors
that can contain teeth and hair – when they were injected with
undifferentiated iPSCs, or cells that have the potential to change into any
kind of cell. However, the tumors grew 20 times slower than in mice,
highlighting an important difference between mice and monkeys.
Fortunately, tumors did not form in monkeys that were injected
with differentiated iPSCs, or cells that were programmed to create bone
cells.
Advancing Research
Researchers say their successful procedure proves that monkeys
will play an important role in research on therapies using iPSCs.
These monkeys will help scientists test and analyze risks associated with the
therapies and improve their safety.
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