Hopes of transplanting insulin-producing cells into diabetics have been boosted by a US-based research team.

In type I diabetics, cells in a gland called the pancreas which produce insulin - a vital body chemical which processes blood sugar - have been destroyed, so the patient needs frequent injections.

We're like alchemists changing lead into gold

Dr Susan Bonner-Weir

A research team from Canada recently proved that cells taken from other sources could be transplanted into a diabetic, and start working well enough to eliminate the need for insulin injections.

However, a major obstacle to transplants is finding enough of the these cells - called islet cells - to produce viable tissue for transplanting.

The latest research, published in the Proceedings of the National Academy of Sciences, could eventually lead to a solution.

The team, from Joslin Diabetes Center at Harvard Medical School in Boston, managed to convert other pancreatic cells - which are present more plentifully, into insulin-producing cells.

Dr Susan Bonner-Weir, who led the research, is hopeful that once the technique is fine-tuned, it may be able to produce large quantities of islet cells from tissue that might simply have been discarded otherwise.

Cells produced insulin

She said: "We're like alchemists changing lead into gold."

The team used a sophisticated technique to revert the ordinary pancreatic cells, called duct cells, into pancreatic stem cells.

These are immature cells that have the potential to become any one of a number of pancreatic cells, all performing different tasks.

Then, by culturing the stem cells in a particular way, they were "encouraged" to grow as islet cells.

Cells are transplanted into the patient's pancreas

The cells, growing onto a microscopic artificial matrix, even started forming structures which looked like the way islet cells are arranged in the pancreas.

Their insulin production increased by between 10 and 15 times, and insulin production was stimulated to increase when exposed to glucose - the sugar carried in the blood.

Mr Derek Gray, a lecturer and honourary consultant in transplantation at the Nuffield Department of Surgery at Oxford University, said the research brought islet transplantation a little closer.

He said that eventually, scientists would able to produce cells in sufficient quantities in the laboratory.

He said: "In the long term what we are looking for are cells in large numbers which are pretty much like human cells, with virtually no risk of rejection, with ideally some sort of cell line which you can keep going in vitro, reducing the need for animals.

"Slow advances are being made. We know now it's possible to cure diabetes with islet transplants - the problem is getting enough cells to give to them.

"I would hope that it would be possible to do this within the next decade - though, of course, there's no guarantee."