BBC Wednesday, 23 May, 2001, 18:05 GMT 19:05 UK

'Grow your own breasts'

Scientists claim a laboratory breakthrough could make it possible or women to grow their own breast implants.

At present, women seeking breast enhancement have had to rely on artificial implants.

However, there is growing evidence that these pose a significant risk to health if they leak.

New Scientist magazine reports that tissue engineer Kevin Cronin, of the Bernard O'Brien Institute of Microsurgery in Melbourne, is working on a safer alternative.

Dr Cronin told a 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.

Scientists have previously carried out experiments on animals in which they have grown tissue in the lab and transplanted back into the body.

Within the body

However, Dr Cronin actually grows the tissue within the body itself.

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. Over time, the scaffold disintegrates.

Dr Cronin says the key to the technique's success 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.

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.

Problems

Mr Dai Davis, a plastic surgeon from Stanford Hospital in London, says supplying blood to the new tissue will be difficult.

He told New Scientist: "We can move fat around [during breast enlargements], but we can't always vascularise it - it calcifies or just disappears altogether."

Tissue engineer Julia Polak from Imperial College School of Medicine in London warned that the technique could be fraught with danger if used to re-build the breasts of women who have had breast cancer.

"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."

However, she said the technique did 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."

Christine Williamson, head of the pressure group Silicon Support UK, said artificial implants had ruined the health of many women.

She said research from the US indicated that silicon implants increased the risk of cancer, suicide and diseases of the connective tissue.

She told BBC News Online: "This technique could be wonderful news for women who have had a mastectomy or problems with only one breast growing. It could save a lot of them dying or becoming seriously ill.

"The complications associated with artificial implants are now coming to light as proper research is done for the first time.

Ms Williamson said she would be happy to be the first human to test the technique.

-- Anonymous, May 23, 2001