Breast Boost

19:00 23 May 01


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.



Secret chamber



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.



Disappearing fat



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 [during breast enlargements], 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.



Hard to control



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 cosmetic surgery applications.

"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.


Marina Murphy



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