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Woman could soon be able to grow their own natul breast transplants.
19:00
23 May 2001
Silicone
breast implants could soon be unnecessary, claim researchers in
Australia. They say their work will make it possible for women to grow
their own.
Tissue
engineer Kevin Cronin of the Bernard O''Brien Institute of Microsurgery
in Melbourne told delegates at a recent meeting of the Royal
Australasian College of Surgeons that he has successfully grown breast
and fat tissue in rats, mice and rabbits. If the
technique works in
people, it could be used for cosmetic surgery or breast reconstruction
after mastectomy.
Rather
than growing the patient''s tissue in the lab and then transplanting it
back into the body, as has been done in animal studies in the past,
Cronin grows the tissue on site.
A "
chamber" containing a scaffold is implanted into the area where new
tissue is needed. Cells from surrounding tissue then migrate into the
chamber and form a three-dimensional blob of tissue, in what Cronin
calls a "wound-healing" response. Over time, the scaffold disintegrates.
The
key to the technique''s success, says Cronin, is a "vascular loop" in
the chamber that generates new blood vessels to supply the growing
tissue. But he won''t reveal details about how it works or what it is
made of until a patent has been granted.
Cronin
has already grown fat and breast tissues in female mice by implanting
the chamber into their groin fat pad. This area is on the animals''
"milk line", where the cells are pre-programmed to form breast and fat
tissue.
Growing
human breasts would involve a similar technique. Immune rejection
wouldn''t be a problem, but Cronin''s mice did occasionally develop
infections around the implanted chambers.
Dai
Davis, a plastic surgeon from Stanford Hospital in London, says
supplying blood to the new tissue will be difficult. "We can move fat
around
, but we can''t always vascularise
it... it calcifies or just disappears altogether," he says.
He
also points out that there could be cancer risks. "If you are using
cells from a woman who has had breast cancer, how do you know that the
new tissue is not also going to turn into a cancer?"
Tissue
engineer Julia Polak from Imperial College School of Medicine in London
agrees. "In the case of someone who has already had breast cancer, it
would be difficult to ensure that the cells used to regenerate the
breast tissue did not also contain the cancer-causing genetic
machinery," she warns.
But
she says the technique does have potential. "It is certainly exciting.
It is the way tissue engineering should be going - getting the body to
regenerate itself rather than trying to grow complex body parts in a
''test tube''."
Cronin predicts that financial backing to develop his new technology will centre on lications.
"There is an obvious spin-off into breast augmentation and facial aesthetic surgery," he says.
But
he does admit the end result could be hard to control. "We were just so
happy at getting the desired tissue to grow at all that we haven''t even
got around to working out how to control issues such as size and
shape," he says.