Livers grown in the laboratory could eventually solve organ transplant shortage
Made-to-measure organs for transplantation are a step closer to reality after scientists grew miniature human livers in the laboratory.

By Richard Alleyne, Science Correspondent
Published: 1:00PM GMT 31 Oct 2010
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The researchers created "working livers" the size of a walnut which functioned normally in laboratory conditions.
They believe that in around five years they will be able to upscale the process and transfer the procedure from laboratory to hospital.

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The development could eventually solve the transplant shortage and also remove the need for powerful drugs to prevent the body rejecting the organ.
"We are excited about the possibilities this research represents, but must stress that we're at an early stage and many technical hurdles must be overcome before it could benefit patients," said the project director, Associate Professor Shay Soker from the Wake Forest Institute for Regenerative Medicine in North Carolina.
"Not only must we learn how to grow billions of liver cells at one time in order to engineer livers large enough for patients, but we must determine whether these organs are safe to use in patients."
More than 600 liver transplants are carried out each year in Britain, but it is estimated that more than a fifth of patients die waiting.
Many livers have to be discarded because they are too old or too damaged to be of any use.
The technology opens up the prospect of growing other replacement organs, including kidneys or pancreases, for patients who are able to donate stem cells.
Artificially grown livers could be transplanted into patients or used to test the safety of experimental drugs.
Pedro Baptista, co-author, said: "Our hope is that once these organs are transplanted, they will maintain and gain function as they continue to develop."
The new technique works by effectively chemically stripping the old liver down too its basic "scaffold" or exoskeleton in a process of called "decellularisation".
Onto this frame of connective tissue and blood vessels, they then regrow the new liver using stem cells from the patient.
Stem cells from embryos could also be used.
Laboratory livers that were nourished by a special bioreactor for a week began growing and functioning like human organs, they said.
Liver disease is the fifth biggest killer in England and Wales, after heart disease, cancer, stroke and respiratory disease, and the only major cause of death that is still increasing year on year.
Some 16,087 people in Britain died from liver disease in 2008, a 4.5 per cent increase on the previous year, and the number of deaths is predicted to double in 20 years.
Sarah Matthews, for the British Liver Trust, said: "Technology such as this is much needed. Currently supply isn't meeting demand, and for every one person who receives a liver transplant, 10 people die.
"Expanding waistbands and heavy drinking habits are having an impact on the quality of donor organs available in the UK, therefore we desperately need developments in liver science. We are encouraged by these results but would also like to warn patients that this technology is a good few years off from becoming available," she said.
The research was presented at the annual meeting of the American Association for the Study of Liver Diseases in Boston.