Growing human embryonic stem cells in the lab is no small feat. Culturing the finicky, shape-shifting cells is labor intensive and, in some ways, more art than exact science.
But a team of researchers led by Laura Kiessling, a UW professor of biochemistry and chemistry, has developed a culture system that promises a more uniform and, for cells destined for therapy, safer product. The system is inexpensive and takes much of the guesswork out of culturing the all-purpose cells. “It’s a technology that anyone can use,” says Kiessling. “It’s very simple.”
At present, human embryonic stem cells are cultured mostly for use in research settings. And while culture systems have improved over time, scientists still use lab dishes coated with mouse cells or mouse proteins to grow batches of human cells. Doing so, however, increases the chances of contamination by animal pathogens such as viruses, a serious concern for cells that might be used
“The disadvantages of the culture systems commonly used now are that they are undefined—you don’t really know what your cells are in contact with—and there is no uniformity, which means there is batch-to-batch variability,” Kiessling explains. “The system we’ve developed is fully defined and inexpensive.”
Instead of mouse cells or proteins, Kiessling’s new culture system utilizes synthetic, chemically made protein fragments. The system can culture cells in their undifferentiated states for up to three months and possibly longer. It also works for induced pluripotent stem cells, the adult cells genetically reprogrammed to behave like embryonic stem cells.
Cells maintained in the system were subsequently tested to see if they could differentiate into desired cell types, and performed just as well as cells grown in commercially available cell culture systems, Kiessling says.
The first clinical trials involving human embryonic stem cells are underway. As more tests in human patients are initiated, confidence in the safety of those cells will be a top concern, notes Kiessling.