SCIENTISTS have grown near-human kidneys in pigs for the first time.
The “chimera” organs — made up of a mixture of human and pig cells — survived for 28 days inside the animal, Chinese researchers said.
They could pave the way for fully-human organs needed for transplants being grown in pigs in future, helping to meet overwhelming demand.
Dr Liangxue Lai, of Wuyi University, said: “Rat organs have been produced in mice, and mouse organs have been produced in rats.
“But previous attempts to grow human organs in pigs have not succeeded.
“Our approach improves the integration of human cells into recipient tissues and allows us to grow human organs in pigs.”
Around 5,000 Brits currently need transplants because they are living with the late stages of deadly kidney disease.
However the average wait time takes two to three years because not enough kidneys are available, with around 1,100 operations performed a year.
The delay is too long for many patients, with 45,000 Brits dying of chronic kidney disease annually.
The new research, published in Cell Stem Cell, sought to address this issue by looking at a new way of getting human organs that doesn’t rely on donors.
Researchers took human stem cells — which can turn into any cell in the body — and put them into pig embryos.
These cells caused the embryos to develop human-like kidneys rather than their normal organs.
The embryos were implanted into surrogate pig mothers, where they developed for four weeks before being taken out to see how the organs fared.
Five embryos had developed structurally normal kidneys that were made up of up to 60 per cent human cells.
The researchers said they may be able to develop a fully human kidney in a pig in the future.
Dr Miguel Esteban, of Guangzhou Institutes of Biomedicine and Health, said: “We would probably need to engineer the pigs in a much more complex way.
“That also brings some additional challenges.”
Independent experts praised the “pioneering” research, saying it could prove to be the “ultimate solution” to the need for more organ transplants.
Professor Darius Widera, of the University of Reading, said: “In the future, this technology could address the current shortage of compatible donors for kidney transplantation.”
