Scientists in South Korea have successfully produced stem cells by cloning embryos that are genetically identical to specific individuals.
The research team has created 11 new lines of stem cells by implanting genetic material from patients into donated eggs, successfully demonstrating the principle of therapeutic cloning, whereby tailored stem cells could be used to repair damaged tissue, or to otherwise treat diseases without problems of rejection.
The team, headed by Professor Hwang Woo-suk, produced the world's first cloned human embryos last year. In that experiment, they only managed to culture stem cells from one of the embryos, having started with 242 donated eggs. The clones were also exact replicas of the egg donors, rather than third parties.
This time, however, the researchers extracted DNA from the skin cells of volunteers - patients aged between 2 and 56, and suffering from a variety of illnesses from diabetes to spinal injuries. The eggs' original DNA was removed and replaced with the samples from the volunteers, a process called nuclear transference that was pioneered by the team that made Dolly the sheep. The stem cells are harvested when the embryos are just six days old.
The team began with 185 eggs, produced 31 embryos and collected stem cells from 11 of those.
Professor Hwang told the Financial Times that South Korea had established its world leading position in the research field because of the supportive political and social attitudes in the country. He contrasted this with attitudes in Europe and the US, where stem cell research is a highly controversial subject. He also said that the availability of eggs from fertile donors was an important factor in his success.
He went on to describe the breakthrough as "a giant step forward towards the day when some of mankind's most devastating diseases and injuries can be effectively treated through the use of therapeutic stem cells", the paper reports.
While many in the scientific community have acclaimed Professor Hwang's breakthrough, pro-life campaigners are less impressed, saying that experiments on human life have no place in a civilised society. Others called for more research into alternative sources of stem cells. ®