Scientists have created the first ever human-sheep hybrids, paving the way for organs to be grown in animals which can be transplanted into humans.

The successful Stanford University project could even open the door to finding a cure for type 1 diabetes by creating healthy pancreases to regulate blood sugar.

While scientists have previously developed human-pig hybrids, sparking excitement that they could use them grow human organs, no team has been able to take it to the next step.

But Stanford's team, which has already successfully transplanted pancreases into mice, is tipped to be the first after now that they have produced a human-sheep model to use.

Scientists have created the first ever human-sheep hybrids, paving the way for organs to be grown in animals which can be transplanted to humans

'We have already generated a mouse pancreas in rats and then transplanted those in to diabetic mouse and were able to show almost a complete cure,' project lead Dr Hiro Nakuachi, a professor of genetics at Stanford, told the American Association for the Advancement of Science conference.

'It could take five years or it could take 10 years but I think eventually we will be able to do this.'

The breakthrough could also help to alleviate the global shortage of organ donors.

Around 76,000 people in the US and 6,500 in the UK are on an organ transplant list, and it can take up to five years to reach the top.

Thirty-two people die a day waiting for a life-saving organ.

The development comes less than two years after the US government said it would approve funding of these controversial experiments, but later backtracked after receiving more than 20,000 complaints from animal rights groups.

Pablo Ross, associate professor of animal science at the University of California, Davis who is part of leading the venture, admitted he harbors similar concerns.

It depends on how far the human cells roam in the animal, he said. If they spread further than intended, it could be impossible to approve for ethical reasons.

But he insisted it is one of the most promising explorations in medicine right now.

Researchers have previously developed human-pig hybrids but have not yet been able to use the process to grow human organs

‘We have this amazing life-saving technology right now [with organ transplantation] but there aren’t enough for everybody,’ said Pablo Ross, associate professor of animal science at the University of California, Davis.

‘Imagine you could grow organs in nine months to an adult size.’

We could even reach a point, he says, when these organs aren’t just used to save lives but that they could circumvent other conditions like diabetes.

Transplanting organs from pig or sheep directly to humans has not been successful but researchers believe using human stem cells may be an alternative solution.

Researchers have previously developed human-pig hybrids but have not yet been able to use the process to grow human organs

To create their 'chimera' - as hybrid animal-humans are called - the team grew embryos containing sheep and human cells, and kept the surrogate animal carrying them alive for three weeks.

The team now plans to implant human stem cells into sheep embryos and hope that human DNA will be able to grow organs such as a pancreas.

It would be a world first if a human organ could be grown inside a sheep.

