Scientists in Canada and Scotland have developed a virus-free method for generating embryonic-like stem cells that does not involve destroying embryos. Scientists say the new approach to growing so-called induced pluripotent stem (iPS) cells is an important step toward creating safe and reliable populations of cells for research and therapy. To create iPS cells, researchers turn back the clock in mature cells. They do this by reactivating dormant genes associated with pluripotency--a primitive state in which a cell has the potential to become any cell type in the body. Scientists first introduced iPS cells in 2006 and since then have...