In an innovative move, a U.S. biotech company has found a new way of making stem cells without destroying embryos, touting it as a way to defuse fierce political and ethical debates over the use of such cells for research and medical treatments.

Some opponents of the research said the method still doesn't satisfy their objections, and many stem cell scientists and their supporters called it inefficient and politically wrong-headed.

Robert Lanza of Clinton, Mass., is vice-president of medical and scientific development at Advanced Cell Technology. The biotech firm has developed a new way of creating stem cells without destroying human embryos.
(Julia Malakie/Associated Press)

But a spokeswoman for U.S. President George W. Bush, who vetoed legislation last month that would have allowed federal funding for embryonic stem cell research in the United States, called it a step in the right direction.

And Robert Lanza, an executive with Advanced Cell Technology, which created the new stem cell lines, said: "This will make it far more difficult to oppose this research."

Stem cells have become a Holy Grail for advocates of patients with a wide variety of illnesses because of the cells' potential to transform into any type of human tissue, perhaps leading to new treatments.

But the Vatican, Bush and others have argued that the promise of stem cells should not be realized at the expense of human life, even in its most nascent stages.

The new method works by taking an embryo at a very early stage of development and removing a single cell, which can be coaxed into spawning an embryonic stem cell line. With only one cell removed, the rest of the embryo retains its full potential for development.

Unlikely to resolve ethical battle

The method was described online Wednesday in the British journal Nature. The journal published a similar paper by Advanced Cell Technology last year demonstrating the technique's viability in mice.

"The science is interesting and important," said John Harris, a professor of bioethics at the University of Manchester in Great Britain, commenting on the biotech company's efforts.

But few believe it will resolve the bitter ethical battle over stem cell research.

"This will please no one," predicted a longtime critic of the company, Glenn McGee, director of the Alden March Bioethics Institute in Albany, N.Y.

Some stem cell researchers complain that the new approach, though it may hold future promise, simply isn't as efficient as their current method of creating stem cells. That procedure involves the destruction of embryos after about five days of development, when they consist of about 100 cells.

Meanwhile, hard-line opponents of stem cell science argue that the technique solves nothing, because even the single cell removed by the new approach could theoretically grow into a full-fledged human.

Some also object over the possibility the procedure could harm the embryo in an unknown way.

Piggybacking on existing treatment

U.S. law currently bans federal funding of any research that harms human embryos.

A White House spokeswoman said the method's eligibility for funding could not yet be determined, "but it is encouraging to see scientists at least making serious efforts to move away from research that involves the destruction of embryos."

Scientists at Advanced Cell, based in Alameda, Calif., devised a clever means of piggybacking on existing fertility treatments to avoid the creation, manipulation or destruction of embryos specifically for the production of stem cells.

The fertility procedure, known as preimplantation genetic diagnosis, or PGD, is used when parents want to avoid having a child with a lethal or severely debilitating birth defect. About 1,000 such procedures are performed each year in the United States.

PGD begins with in vitro fertilization to produce numerous embryos. At a very early stage of development, when the embryos are no more than a ball of eight to 10 cells, a technician extracts a single cell from each one.

The extracted cells are tested for genetic disorders, and those free of defect are then implanted in the mother in the hope they will develop.

The new stem cell production method takes a cell extracted during PGD and allows it to divide. One of the two resulting cells is genetically tested as in normal PGD; the other is cultured to encourage the development of stem cells.