The new work, which is reported today (Jan. 1, 2006) in the journal Nature Biotechnology, 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 harbor viruses or other deleterious agents.

Successfully growing living cells outside the body generally requires providing the cells in a lab dish with the right mix of nutrients, hormones, growth factors and blood serum. But those methods have often depended on animal cells - such as those obtained from mouse embryos in the case of embryonic stem cells - and other animal products to keep the cells alive and thriving in culture. Some scientists worry that animal viruses and other problematic agents might be taken up in the human cells and infect human patients, should those cells be used for therapy.

"All of the concerns about contaminating proteins in existing stem cell lines can essentially be removed using this medium," says the Nature Biotechnology paper's lead author, Tenneille Ludwig, a UW-Madison research scientist working at WiCell who led the effort to develop the new culture media. "This work helps us clear some of the major hurdles for using these cells therapeutically."

"We've been optimizing (culture) 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
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Contact: Terry Devitt
trdevitt@wisc.edu
608-262-8282
University of Wisconsin-Madison
1-Jan-2006