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鈥橞rien 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鈥檚 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 鈥渃hamber鈥� 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
鈥渨ound-healing鈥� response. Over time, the scaffold disintegrates.
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The key to the technique鈥檚 success, says Cronin, is a 鈥渧ascular loop鈥� in the
chamber that generates new blood vessels to supply the growing tissue. But he
won鈥檛 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鈥� 鈥渕ilk line鈥�,
where the cells are pre-programmed to form breast and fat tissue. Growing human
breasts would involve a similar technique. Immune rejection wouldn鈥檛 be a
problem, but Cronin鈥檚 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. 鈥淲e can move fat around [during
breast enlargements], but we can鈥檛 always vascularise it鈥� it calcifies or just
disappears altogether,鈥� he says. He also points out that there could be cancer
risks. 鈥淚f 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?鈥�
Tissue engineer Julia Polak from Imperial College School of Medicine in
London agrees. 鈥淚n 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,鈥� she warns. But she
says the technique does have potential. 鈥淚t is certainly exciting. It is the way
tissue engineering should be going鈥攇etting the body to regenerate itself
rather than trying to grow complex body parts in a 鈥榯est tube鈥�.鈥�
Cronin predicts that financial backing to develop his new technology will
centre on cosmetic surgery applications. 鈥淭here is an obvious spin-off into
breast augmentation and facial aesthetic surgery,鈥� he says. But he does admit
the end result could be hard to control. 鈥淲e were just so happy at getting the
desired tissue to grow at all that we haven鈥檛 even got around to working out how
to control issues such as size and shape,鈥� he says.