The take home is that the technology works, but will now need
progressive development likely lasting years and perhaps decades,
although we already have effective deliverables.
Complex cell structures will surely take plenty of time to master yet
be solvable.
It is obvious though that this biotechnology and that is what it is,
will displace all restoration tasks in medicine and can partially do
that today.
Thus biological replacement will be common with at most the embedding
of carbon fiber to strengthen bone, such as in the skull and teeth.
We all could use teeth enamel with the strength of diamond.
This development along with the restoration of aged cells is our
medical future.
Lab-Grown 'Custom'
Organs May Be Future of Medicine
By DR. JESSICA NOONAN,
ABC News Medical Unit
June 25, 2012
What if dying patients
waiting for an organ transplant could receive a custom,
lab-grown replacement rather than waiting for a donor organ?
To some, this may
sound like science fiction -- and in many ways, it still is. But the
advances in the field of regenerative medicine that made headlines
last week suggest such lab-grown organs may become reality in the
future.
One of these advances
was Swedish scientists' creation of a custom veinthat has
carried blood from a little girl's intestines to her liver for a year
and counting. In another, a group in Japan successfully implanted
lab-grown livers made from human cells into mice -- organs that
metabolized drugs the way they would in a human.
And these developments
may be just the tip of the iceberg. From skin to blood vessels to
solid organs, work is underway to offer more options for patients
with faulty or damaged body parts.
Dr. Anthony Atala,
director of the Wake Forest Institute for Regenerative Medicine in
Winston-Salem, N.C., was part of the first group in the world to
successfully implant a lab-grown organ into the human body. Atala's
interest in the field began when he was training to become a
urologist and saw numerous children who had undergone bladder
replacement surgery. Many of them were experiencing leaks, and some
even suffered ruptures of their new bladders.
"That's when I
really thought, 'Why not try to grow these children new bladders from
their own cells?'" Atala said.
Atala collected a
small number of cells -- about the size of half a postage stamp --
from the original, inadequate bladders of children with spinal cord
birth defects. Each child's own cells were multiplied in the lab and
then placed on a biodegradable scaffolding. In seven weeks, the cells
had grown to fill in the scaffold, creating a new bladder. The
procedure was first performed in 1998, and by 2006 they had seen
long-term success of the organs.
"I still hear
from some of them occasionally," Atala said. "They are
still walking around with their engineered bladders, and they are
happy with them."
Since this first foray
into growing organs, Atala has been one of the many doctors on the
forefront of what some say could one day be a new paradigm in
medicine -- growing spare parts from a patient's own cells.
Atala currently heads
up more than 300 researchers in the Wake Forest University lab who
are working on growing more than 30 different organs and body
tissues.
In one trial for the
U.S. Armed Forces, his team is collecting healthy skin cells from
injured soldiers, processing them, and then spraying them onto battle
wounds as a tailored treatment for healing. For deeper wounds, they
are in the process of developing an ink jet printer that scans a
wound and creates a custom map of the defect.
"After the scan,
the printer can go back and print multiple layers of cells right over
the wound," Atala said.
The idea of using a
patient's own cells rather than relying on those of a donor is
important because it eliminates the need to find a "match."
For any transplant procedure there is a concern that tissues from a
donor will be rejected by a recipient's body.
Even though doctors
carefully analyze specimens under a microscope to find the most
compatible individuals, and even despite the powerful drugs used to
prevent the recipient's immune system from attacking the new body
part, the risk of rejection still causes doctors to hold their breath
in the days following a transplant.
Custom-made organs
from a patient's own tissues would solve this problem, obviating the
need for strong immune-suppressing medications that come with
significant side effects.
The other potential
benefit lies in availability. Growing a replacement tissue or organ
in the lab eliminates the dependence on waiting for a donor to die.
These parts cannot be grown overnight, but with people currently
waiting months to years for donor organs, there might be a point at
which the amount of time taken to grow a replacement is shorter than
the wait for a donated one.
It's a bright future.
But many hurdles remain before widespread use becomes a reality. Both
time and cost are obstacles to replacing even the simplest
structures, doctors said.
"The organization
and resources required for the process are significant and would
severely limit the applicability of the treatment strategy to large
groups of patients," said Dr. William Marston, professor and
chief in the division of vascular surgery at University of North
Carolina Hospitals in Chapel Hill.
And so far, the proof
that these creations are worth all the effort is a lacking. Experts
say more studies comparing the regenerated parts to donor and
artificial parts are needed in order to show they are at least as
good -- better, ideally -- than the current treatments.
But even before we get
this far, the tools need to catch up to the vision. And for now at
least, the technology to create some of the most in-demand organs for
human use is simply not yet there.
Currently, scientists
are able to create some types of tissues for human transplant use.
The simplest kind are flat, simple structures such as skin that
consist of one cell type. Tubular structures that involve two cell
types, such as blood vessels, are also possible using current
techniques and technology. Most recently, scientists have been able
to create hollow organs, like the stomach and bladder, that only
require two cell types but have a more complex shape.
What still lies out of
reach are the solid organs, such as the liver or kidneys.
"They require so
many more cells per centimeter," said Atala. "And they need
more blood vessels to keep the cells alive."
Despite the
challenges, Atala has had some early success with the creation of
solid organs. In 2010, his group was the first in the world to create
a functioning liver from human cells.
So far, these livers
have only been tested in an artificial lab setting. They would still
need to be studied in animal models before they could ever be
considered for humans. Also, Atala's livers weigh only one-fifth of
an ounce. They would need to reach at least one pound to have a
chance of sustaining human life -- "not an easy task,"
according to Atala.
But his group is not
alone. Researchers around the world are working feverishly towards
making lab-grown solid organs a possibility. The Boston University
Center for Regenerative Medicine successfully created rat lungs in
2010. They were even able to transplant the lungs into live rats and
sustain life for about six hours.
While the widespread
use of regenerated body parts may still be years away, these small
successes in lab and animal studies leave scientists hopeful that
solid organ regeneration may someday be a reality.
"I think the
field will evolve one area at a time," Atala said. "We just
keep going and advancing."
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