French doctors on Friday said they had used human embryonic stem cells to grow skin that one day may be used as potentially life-saving temporary patches for patients suffering bad burns.
The laboratory achievement has been tested on mice and not yet on human volunteers, but the researchers believe it could be a boon for surgeons striving to save patients awaiting skin grafts.
For more than two decades, the main way to help burns patients has been to take some of their skin cells, called keratinocytes, and grow them in a lab in order to replace the damaged area.
But this process takes around three weeks, and dehydration and infection for the patient can be fatal.
Two other interim possibilities to cover the wounds are "decellularised" skin from cadavers, but this source is rare, and biosynthetic substitutes that include bovine collagen. Both carry the risk of rejection by the patient's immune system.
The new technique, reported in The Lancet, draws on the power of stem cells from human embryos -- the highly potent, but also controversial, master cells that grow into the body's various tissues.
In the experiments, a team led by Christine Baldeschi of France's Institute for Stem Cell Therapy and Exploration of Monogenic Diseases seeded embryonic stem cells onto so-called feeder cells.
For the next 40 days, the tandem cells were cultured in a cocktail of drugs to make them grow, and then attached to an artificial matrix replicating the structure of skin.
The keratinocyte-like cells were then grafted onto five lab mice, which 12 weeks later developed a healthy skin.
In an interview with AFP, team member Marc Peschanski said more work needed to be done to adapt the technique to humans.
"Overall, we have a timeframe (for clinical trials) of the end of 2011, although this date is conditional upon a number of factors that could intervene at any moment," he said.
Embryonic stem cells are taken from early-stage embryos that are few days old, and then are allowed to reproduce in stem-cell "lines."
They are the most versatile of premature cells, but their use has stirred an ethics debate, especially in the United States, where some Christian religious groups say the technique amounts to murder.