Culturing embryonic stem cells can be a genuine pain. These finicky, constantly-shifting cells require quite a bit of care and growing them can be more art than exact science.
However, a team of researchers at the University of Wisconsin-Madison has reported the development of a fully defined culture system that could provide much more uniform results and for those cells that might be used for therapy, they could provide a safer product.
The research team, UW-Madison professor of chemistry Laura Kiessling, unveiled an inexpensive system that takes much of the guess work out of culturing the embryonic stem cells.
“It’s a technology that anyone can use,” says Kiessling. “It’s very simple.”
Presently, human embryonic stem cells are cultured for research purposes, mostly. Culture systems have improved over time, but cell scientists still use plastic surfaces covered with mouse cells or mouse proteins to grow batches of human embryonic stem cells. Both embryonic or induced stem cells are grown with these cell culture conditions. These culture conditions, however, increases the chances of contamination of the cells by animal pathogens such as viruses, a serious concern for cells that might be used in therapy.
The new culture system utilizes a synthetic, chemically-made substrate of protein fragments, and peptides that have an affinity for binding stem cells. If used in combination with a defined growth medium, the system devised by the Wisconsin team can culture cells in their undifferentiated states for up to three months and possibly longer. The culture system, according to the new report, also works for induced pluripotent stem cells, those adult cells genetically reprogrammed to behave like embryonic stem cells.
Kiessling noted that embryonic stem cells maintained in this culture system were subsequently tested to see if they could differentiate into desired cell types. Embryonic stem cells grown in the defined culture medium performed just as well as cells grown in less defined, commercially available cell culture systems.
The first clinical trials involving human embryonic stem cells are underway and that as more tests in human patients are initiated, confidence in the safety of the cells will be central to patients and clinicians.
“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.”