Scientists seeking new ways to repair damaged arteries and ailing hearts have processed stem cells from a human embryo to form tiny vessels.It is the first time that human embryonic stem cells have been nutured to the point where they will develop into blood vessels that could nourish the body, according to Robert Langer, leader of a laboratory team at the Massachusetts Insititute of Technology. But it is not likely to be the last, as scientists continue to pursue research into uses of stem cell despite the debate over the ethics of using the cells. The new development has been reported recently on online issue of proceedings of the National Academy of Sciences. Dr.John Gearhart of the Johns Hopkins School of Medicine said the research is a "nice illustration" of how stem cells can serve as a source of various types of cells in blood cells, in blood vessels."I think this is terrific," said Gearhart, who was not part of the research team. It's another good example of the isloation of an important cell type from human embryonic stem cells. These are the kinds of papers we are going to see in great number,Gearhart added. Langer said that the work shows that endothelial cells can be made from human embryonic stem cless. Endothelial cells are found in the veins, arteries and lymph tissue.
They are key to the cellular structures that carries blood throughout the body. He said that if the technique is refined, scientists may eventually be able to make bolld vessels in the laboratory, which can be used to replace diseased arteries in the body."Thousands of operations are done every year where doctors take vessels from one part of the body and transplant them to another" said Langer. Such vessels might be made out side body from embryonic stem cells. Endothelial cells in the laboratory might also be used to restore circulation to cells damaged by heart attacks. He said the processed stem cells may be able to reestablish blood flow in case of heart failures due to blocked arteries. The research was conducted under a private grant but Langer said the cell culture used in one of the 61 cell cultures that have been apporved by the National Insittutes of Health for Federally Funded Research. The use of embryonic stem cells is controversial because extracting the cells kills a living human embryo.