The new work done at the University of Wisconsin-Madison, helps move stem cells a small step closer to clinical reality by completely ridding the culture medium in which they are grown of animal products that could harbour viruses or other deleterious agents.
"We've been optimising media on the existing stem cell lines since 1998, but it has only been recently that there have been dramatic improvements," says James Thomson, the senior author of the new study and a UW-Madison professor of anatomy who seven years ago was the first to successfully grow human embryonic stem cells in the lab. "This is the first time it has been possible for us to derive new cell lines in completely defined conditions in medium that completely lacks animal products."
Other groups, Thomson notes, have cultured established human embryonic stem cells in animal-product free media, but those efforts included the use of poorly defined or proprietary products, and no one has previously demonstrated derivation of new cell lines in defined conditions.
The two new Wisconsin stem cell lines have survived for more than seven months in the new culture medium. Thomson says one of the new lines had an abnormal chromosome at four months, while the second line initially was normal but developed an abnormality by seven months.
In addition to testing the new stem cell culture medium on new lines, Thomson's group successfully cultured four existing stem cell lines in the new culture mix for extended periods, and their chromosomes remained normal.
The two new Wisconsin stem cell lines were derived from five blastocysts, embryos less than a week old and which were donated for research with the informed, written consent of patients who were no longer undergoing treatment for infertility.
MEDICA.de; Source: University of Wisconsin-Madison