Stem cells, the progenitors of living tissue, could alter the face of cosmetic surgery, claim scientists today, who report that implants of flesh grown from bone marrow could provide better material for reconstructive surgery following cancer treatment.

Jeremy Mao, of the University of Illinois, in Chicago, told the American Association for the Advancement of Science meeting in Washington that saline and silicone implants for breast augmentation could leak, rupture or mask the growth of tumours.

But implants from a patient's natural tissue, cultured outside the body from stem cells and then grown around biodegradable scaffolds to provide the right shape, might one day sidestep those problems.

In 2003, American plastic surgeons performed more than 8.7m operations, including 6.2m reconstructions, many of them following tumour removal. But even purely cosmetic procedures involving lips, breasts and buttocks, have involved adding "bulk", and over 10 years "tissue engineers" have been working on finding better ways to sculpt human flesh.

Dr Mao and his colleagues will report in April, in the journal Tissue Engineering, that they took adipose, or fat-generating cells, from a human donor and seeded them on to a liquid skeleton of hydrogel, which could be moulded into any shape.

They planted some of these forms in to laboratory mice with lowered immune systems - which meant the alien tissue would not be rejected - and looked again after four weeks. By then, the implants had generated more adipose tissue, and had also kept their shape and dimension.

It will be many be years before humans can be fitted with implants made from their own tissue. But the experiment shows that it is possible.

"What we foresee for humans is that, say [someone] is unfortunate enough to have breast cancer surgery and needs breast reconstruction - you can take adipose stem cells from her and do the same procedure," Dr Mao said. "You would mould them into the shape of the other normal breast, or the missing portion of breast, and instead of implanting silicone or saline structures use the stem-cell derived adipose implant.

"There are several disadvantages of current procedures. They can rupture or leak, and they can block breast cancer detection in the future. The technique is also applicable for other soft tissue - facial tissue like the lips and so on."

In 2001, after years of debate, Britain authorised controversial medical research that was using embryo stem cells. These are the agents that in 40 weeks turn a single fertilised egg into 10 trillion cells of up to 300 different kinds. Embryo stem cell research in the US has not got government support, but researchers have claimed some remarkable successes there using "adult" stem cells - cells capable of generating only a limited range of tissue.

In their research, Dr Mao and his colleagues started with a line of stem cells from the bone marrow of a healthy young volunteer. Under the right conditions, these cells transformed themselves into bone, cartilage and fat.

So stem cells could offer the raw material for rebuilding damaged bodies or enhancing wrinkled faces. But researchers still have to work out how to turn cells in a lab dish into implants that will go on growing once they have been transferred to a patient, and which will keep their shape.

"You could do a liposuction, harvest the stem cells and use them for regeneration," Dr Mao said. "Patients will have a choice - a stem cell-grown structure or an artificial implant. How fast this will progress is a matter of regulatory issues that are hard to predict. The technology should be mature within a decade."