From Scientific American:
Soon after the exciting discovery of a method to turn human adult cells into stem cells in 2007 came the frustration of actually trying to make that transformation efficient. In creating induced pluripotent stem (iPS) cells, scientists typically only get 0.01 percent of a sample of human fibroblast (skin) cells to change. A group led by Duanqing Pei of the Guangzhou Institutes of Biomedicine and Health in China has found that a simple chemical can boost the efficiency by 100-fold—namely, vitamin C.
The researchers can trigger the conversion to iPS cells by introducing genes or proteins to adult cells, typically with a virus. Once the cells become pluripotent, they have the ability to become any cell in the body, thereby offering the promise of repairing damaged organs and treating disease. But scientists have yet to come up with the ideal recipe. “It’s a worldwide effort to boost efficiency and make this more practical for much wider participation from the scientific community,” Pei says.
More here.