Stem cells are so fragile that in shipping them from one lab to another, almost 99 percent of the cells die. UW-Madison researchers have pioneered a technique to improve stem cell survival by up to a factor of 20.
Currently, cells are \cryopreserved"" for transportation, meaning they are frozen at -320 degrees Fahrenheit to prevent them from disintegrating. But the freezing process can create ice crystals in the cells, which destroys the cell membranes.
The researchers, UW-Madison professors of chemical engineering Sean Palacek and Juan de Pablo, discovered a preservative that can be added to the solution to inhibit ice crystal formation.
The preservative is trehalose, a sugar produced by some organisms that can survive at low temperatures.
""We add trehalose to the matrix [a gelatin-like solution] and that protects the cells,"" said de Pablo. Trehalose is already used to protect other types of cells used in research, so it was a natural choice as a stem cell preservative.
Anyone else could have come up with the idea, acknowledges de Pablo, but ""we're one of only three or four groups in the country with the expertise to freeze cells. We're among the only ones who could turn this theory into practice."" De Pablo and Palacek will publish their results in an upcoming issue of the journal Biotechnology and Bioengineering.
Stem cells are early-stage cells that can be turned into any type of cell, such as a heart, muscle or brain cell.
""Stem cells are really the future of medicine; they will help us improve health care in ways we can't even imagine now,"" said de Pablo. Still, he says his team's research has even more lofty goals for the technology it is pioneering.
Freezing cells has always been fraught with practical limitations, but if de Pablo and Palacek can improve the cells' ability to remain viable even after freezing, they may be able to freeze-dry other cells, including tissues, organs and especially blood.
This research comes as welcome news to organizations who depend on tissue donations.
""Right now, blood donations we receive are good for 42 days. If they're not used in that time, we have to discard them,"" said Sara O'Brien, spokeswoman for the American Red Cross. ""But if we had [freeze-dried blood] products, we could extend their shelf life indefinitely.""
O'Brien said this would also give the Red Cross improved power to deal with large-scale disasters.
""Freeze-dried blood? Wow-that would be an absolute blessing,"" she said.
