Working with stem cells
comes at a price. When
isolated, 99 percent of stem
cells die, making it prohibitively
difficult to manipulate their genes or
expand their numbers for clinical use.
By tinkering with the medium in
which cells are grown, researchers at
the Salk Institute for Biological Studies
created a type of stem cell with a
survival rate of 30 to 40 percent, vs.
1 percent. The cells are far easier to
culture, and their genetic defects are
more readily repaired.
The human version of the cells,
called region-selective pluripotent
stem cells, or rsPSCs, can also grow
inside a mouse, something other
human stem cells can’t do, says Jun
Wu, a research associate involved in
the work, published in May in Nature.
“It offers the first proof of concept
that it’s possible to incorporate
human cells efficiently into another
species,” Wu says. This suggests
someday it may be possible to grow
a human organ, such as a pancreas,
inside a pig and then transplant it
into a diabetic patient.