Human Liver Grown From Umbilical Cord Stem Cells
By Fiona MacRae, Daily Mail, October 31, 2006
In a breakthrough that will one day supply entire organs for transplants, British scientists have grown the world’s first artificial liver from stem cells.
The technique will be developed to ultimately create a full-size functioning liver. The liver that was grown, dubbed the “mini-liver”, is currently the size of a one pence piece.
The tissue was created from blood taken from babies' umbilical cords just a few minutes after birth and the Newcastle University researchers called it a “Eureka moment”.
Preventing disasters such as the recent “Elephant Man” drug trial is a possibility since the mini organ can be used to test new drugs. Animal experiments would also be reduced by using the lab-grown liver tissue.
Repairing livers damaged by disease, injury, alcohol abuse, and paracetamol overdose could be possible within the next 5 years.
Entire organ transplants could take place using organs grown in a lab in only 15 years.
Hundreds of Britons are in desperate need of a new liver each year; the breakthrough provides renewed hope for the future.
72 people died waiting for a suitable donor in 2004. And 336 patients are currently waiting for a liver transplant.
The liver tissue is created from stem cells - blank cells capable of developing into different types of tissue - found in blood from the umbilical cord.
The stem cells were successfully separated from the blood removed from the umbilical cord minutes after birth by the Newcastle scientists working in partnership with US experts.
The stem cells were placed inside a piece of electrical equipment developed by NASA to mimic the effects of weightlessness, called a “bioreactor”. The cells multiplied more quickly than usual because they were free from the force of gravity.
The cells were then coaxed into becoming liver tissue using various hormones and chemicals.
So far, tiny pieces of tissue, less than an inch in diameter have been created.
Sections of tissue, large enough for transplant into sick patients will eventually be possible given some time.
The tissue could be used to test new drugs within the next two years say the Newcastle scientists. Prior to animal and human trials, the current method of testing drugs is conducted within a test tube.
However, the testing procedure is not without risk. Six healthy volunteers were left fighting for their lives during Northwick Park drug trials earlier this year.
Before new drugs are given to humans, lab-grown human tissue could be used to determine if there are any flaws in the formula that need to be corrected.
"We take the stem cells from the umbilical cord blood and make small mini-livers,” said Colin, a professor of regenerative medicine at Newcastle University.
"We then give them to pharmaceutical companies and they can use them to test new drugs on.
"It could prevent the situation that happened earlier this year when those six patients had a massive reaction to the drugs they were testing."
The number of animal experiments could also be reduced with the use of mini-livers.
The artificial liver could be used to directly benefit people's health within 5 years.
In much the same way a dialysis machine is used to treat kidney failure, the researchers envision sections of artificial liver being used to keep patients needing liver transplants alive.
The liver’s remarkable ability to quickly regenerate itself would be taken advantage of with this technique.
All of the functions that are usually carried out by a patient’s own liver would be taken over by an artificial liver that the patient would be hooked up to.
The patients own liver would be afforded enough resting time to regenerate and repair any damage while the artificial liver would do the work during several “dialysis” sessions a day over a period of several months.
The search for a suitable donor for transplant could also be extended by prolonging the health of the individual patient.
For those whose livers have been damaged beyond repair, it is hoped that it will be possible to create sections of liver suitable for transplant within the next 15 years.
This procedure would eliminate the need for an entire liver transplant in many cases.
Whole livers created in a lab for transplant use would come several years later.
The Newcastle team is the first to create sizeable sections of tissue from stem cells from the umbilical cord. Other researchers have created liver cells from embryonic stem cells.
However, the latter process leads to the death of the embryo. This makes the Newcastle team’s breakthrough incredibly appealing given that it will be ethically acceptable.
The Newcastle researchers foresee a time when cord blood from millions of babies born each year is banked, creating a worldwide donor register for liver dialysis and transplant.
For patients with liver problems, computerized registries could then match the cord blood with their tissue type or immune system to minimize the risk of rejection.
There are approximately a dozen cord blood banks around the UK and more than 11,000 British parents have so far chosen to preserve their children’s cord blood. It is already used to treat leukemia.
"One hundred million children are born around the world every year - that is 100 million different tissue types,” says Professor McGuckin.
"With that number of children being born every year, we should be able to find a tissue for me and you and every other person who doesn't have stem cells banked."
Co-researcher Dr. Nico said that their, “dream is that every metropolitan city would have such a bank.”
"If you could type the blood all, you would have to do is dial it up on your computer and fly it from Bristol to Newcastle or even Newcastle to Kuala Lumpur," he added.
Many liver experts have welcomed the breakthrough.
“The stem cell is going to change the way we deliver treatment,” said Professor Nagy, of London's Hammersmith Hospital.
Alison, Chief Executive of the British Liver Trust said that, "stem cell technology represents a huge leap forward in treating many diseases. With liver disease in particular it has the potential for tremendous advances."
A spokesman for UK Transplant, which runs the country's organ donor register, added that, “there is a lot going on in research that may have benefits for transplant patients. But, in the here and now, the obvious way to help these people is by more people adding their names to the organ donor register and to make their wishes known to their family."