PrimeGen, a small biotech company based in Irvine, CA, says that it has solved one of the major hurdles in using reprogrammed stem cells for human therapies. Last year, scientists announced that they had successfully created embryonic-like stem cells from adult cells, circumventing the ethical and technical hurdles associated with embryonic stem cells. But the method used viruses to deliver genes, raising concerns over cancer risk.

According to an article in Forbes,

PrimeGen claimed Tuesday it had circumvented this problem. Instead of genes, it uses unspecified carbon-based “delivery particles” to insert four proteins into cells to stimulate the reprogramming process. This caused some of the cells to revert to being much like embryonic stem cells, PrimeGen said. PrimeGen said it has done the experiment with retinal, skin and testicular cells.

“Our goals are ambitious–we believe with this therapy, we can be in clinic in 2010,” said PrimeGen president John Sundsmo in an interview. He said he couldn’t release details on what the delivery particles are until the company finalizes an agreement with a corporate partner.

However, some scientists are skeptical. Rather than being published in a peer-reviewed scientific journal, the findings were released during a brief presentation at a stem-cell industry conference in New York.

According to Forbes,

Many outside scientists said they weren’t familiar with the work and weren’t quite sure what to think. “Until the work goes through [peer-review], it would be difficult to evaluate,” says James Thomson, the researcher at University of Wisconsin, Madison, who created the first embryonic stem cells in 1998. George Daley, of Harvard University, said he was “pretty suspicious of publication by press release.”

Nonetheless, “if this is real it really is a significant step,” says Arnold Kriegstein, director of the Institute for Regenerative Medicine at U.C.-San Francisco. “They could be on to something.”