A research team at Sydney's Prince of Wales Hospital has developed and patented a technique for growing human embryonic stem (ES) cells without using animal-derived feeder cells.

Using fibroblast skin cells from aborted human foetuses, Dr Kuldip Sidhu's team, in the hospital's diabetes transplant unit, has developed the first feeder-cell system that does involve animal cells.

Sidhu said all but one of the 240-odd human stem cell lines currently maintained in culture around the world are sustained by a layer of feeder cells, typically from mice, and fetal calf serum. Using animal feeder cells and animal serum involves a theoretical risk that animal viruses or prion proteins could contaminate the ES cells and infect transplant recipients.

The new feeder cell line has been dubbed Endeavour 1. The Australian Patent Office issued a patent for the new technology on January 10.

"If we want to use embryonic stem cells for therapeutic purposes, we need to get rid of all animal products," Sidhu said. "We're now a step closer to providing those conditions."

Sidhu's team is working with an ES cell line imported from the US in 1998, one of the five human ES cell lines approved for stem-cell research in Australia before April 2002, when Commonwealth legislation barred researchers from creating new stem-cell lines from surplus IVF fetuses.

The researchers are now seeking to establish collaborative projects with other stem cell research groups in Australia and overseas.