There will be many important clinical trials of stem cells in 2011. They will test therapies to treat paralysis and blindness could reveal the therapeutic potential of human embryonic stem cells
Human embryonic stem cells (HESCs) are unique in their ability to form all 200 tissues of the human body. In principle, cells derived from them could regenerate almost any tissue or organ. But because they come from embryos that are later destroyed, their use is controversial. To pacify the opposition the stem cells need to live up to expectation.
Within weeks, surgeons will inject retinal cells derived from hESCs into the eye of an individual with Stargardt’s macular dystrophy, in the hope of delaying or preventing blindness, says Robert Lanza of Advanced Cell Technology (ACT) in Worcester, Massachusetts, which is developing the treatment. Eleven more patients are due to be injected in 2011. Any improvements in vision should be obvious and could take as little as six weeks to emerge.
The eye, however, is something of a special case. Insulated from the immune system, cells there are less likely to be rejected than in other parts of the body. To find out whether hESCs have broader therapeutic potential, we need to look to another, more ambitious trial.
In October, a paralysed person received a spinal injection of hESC-derived oligodendrocyte progenitor cells. Ten more patients are due to receive cells in 2011. The stem cells should repair damaged nerves and prompt the growth of new ones, says Geron of Menlo Park, California, which is developing this treatment.