Keeping Stem Cells Cold, Very Cold

Günter Fuhr isn't just head of the Fraunhofer Institut of Biomedical Technology. He's also a sort of bank director, although there are no ATM's outside his branch.

His institute doesn't deal with cold cash, but extremely cold temperatures. It's a cryogenics bank, developed and built by his team, which stores stem cell cultures.

In order to conduct research on the stem cell cultures, they have to be available at any time. That means, they must be preserved and stored, frozen in liquid nitrogen at negative 196 degrees Celsius, according to Fuhr.

"Normally cells are stored in plastic tubes that are about a centimeter long, and which hold about 10 milliliters of fluid," Fuhr sagt. "That is billions of cells. And usually one only needs just one drop with several million cells to have enough to answer many questions in medicine and biotech."

That is why the Fraunhofer Institute in St. Ingbert in southwest Germany is developing a vial that can dispense one million cells at a time. It is something akin to the films that tablets sometimes come in that allow them to be dispensed one at a time. But these vials can keep the stem cells in good condition for up to 30 years.

One of the institute's visions of the near future involves taking blood from the placenta and umbilical cord of a baby, which contain stem cells, shortly after birth. The cell cultures would then go to the cryobank where they would be frozen and stored, ideally for the lifetime of the individual. If the person were to later develop a serious illness, the stem cells could be defrosted and used in treatment.

Unique in the world

The Fraunhofer Insitute's cryobank is the only one of its kind in the world. Right now, it has the capacity to store the cell cultures of every single German resident in its 150 tanks. The maintenance of the cultures, however, is fairly complicated. To stay viable, samples cannot ice up and can only be handled with a special apparatus.

In order that the institute's databank can keep track of their condition, special chips that can withstand extremely low temperatures had to be developed that set off an alarm if a sample has been stored improperly.

Commercial future

Some of the tanks already have commercial uses, as several pharmaceutical companies are paying to store valuable samples in them. Since each of the tanks is valued at several million euros, security measures are strict, and somewhat unusual.

"The fire department can't extinguish any fires that might break out around them with water, since it would leak into the tanks and ruin them," said Fuhr. "The tanks are very special containers and are vacuum-sealed. They can withstand some 10 to 20 seconds right in the middle of a fire."

The institute has been able to sell its cryogenic technology to companies in Germany, the US and Spain. Other countries, such as Korea and Japan, have also shown interest. But there is still a ways to go before a profit is realized. The institute has made about 250,000 euros ($298,000) on an investment of three million.

Despite the negative profit margins, Fuhr says the institute is on the right path. In the US, investment in cryobanks is booming; in California alone, the governor has announced a $150 million investment in cell banks.

"We have much smaller sums to work with," he said. "But we have the know-how."