Incredible potential: Image shows IPS embryonic stem cells (L, top), which can develop, into cells of many tissues, such as muscle (L, bottom), nerves (R, bottom) and cartilage (R, top). Harnessing the power of stem cells would revolutionise medicine.
Credit: AFP/Kyoto University/Shinya Yamanaka
Embryonic stem cells are the primitive cells that grow into the roughly 200 types of cell that comprise the body's tissues.
Scientists aim to coax these cells into becoming lab-dish replacements for heart, liver, skin, eye, brain, nerve and other cells destroyed by disease, accident, war or normal wear-and-tear.
Parkinson's disease, Alzheimer's, Type 1 diabetes, cancer and cardiac degeneration are among the many disorders that, in theory, could be healed by this wonder cure.
Of the two categories of stem cells, the biggest interest by far has focused on embryonic stem cells. These are so-called pluripotent cells, meaning that they have ability to differentiate, or diversify, into many different tissues.
But embryonic stem cell research has been controversial. These master cells are extracted from early embryos that are allowed to grow for five to six days in culture.
The harvested stem cells are kept in self-replicating 'lines' for study, but the embryos themselves – usually surplus embryos from in-vitro fertilisation (IVF) – are destroyed by the process.
American Christian conservatives have long opposed this research, saying that a human embryo equates to a human life.
In August 2001, former president George W. Bush banned all U.S. federal funding for research that entailed new lines of human embryonic stem cells. That move caused an outcry among U.S. researchers, who warned investment and talent in their field would shift to other countries.
In July 2006, an attempt in the senate to lift some restrictions was barred by Bush, wielding his presidential veto for the first time.
President Barack Obama has vowed to scrap the ban, and a White House official said the president would sign executive order Monday reversing Bush administration restrictions on federal funding for embryonic stem cell research.
The official would not divulge the exact wording of the order, but confirmed, on condition of anonymity, that it would be in line with Obama's campaign vow to restore funding to embryonic stem cell research.
