IT'S ALIVE!! BEATING HEART CREATED IN LAB

"It's Alive!!! It's Alive!!!!" --  Dr. Victor Frankenstein

 

BEATING HEART CREATED IN LABORATORY

Julie Steenhuysen
Rueters -- Monday, 14 January 2008

US researchers have created a beating heart in the laboratory and say the discovery may lead to customised organ transplants for people.

The study, which appears in the latest Nature Medicine  journal, offers a way to fulfil the promise of using stem cells to grow tailor-made organs for transplant.

"The hope would be we could generate an organ that matched your body," lead researcher Professor Doris Taylor, director of the  University of Minnesota  Centre for Cardiovascular Repair, says.

Using a process called decellularisation, the researchers grew functioning heart tissue from dead rat and pig hearts.

Decellularisation is the process of killing all the cells in an organ, in this case an animal cadaver heart, and preserving the architecture of the organ such as the chambers, valves and blood vessel structure.

Taylor says she knew decellularisation had been used in making tissue heart valves and blood vessels and decided to try it on whole organs.

"We hung these organs in the lab and we washed out all the cells. When you are done, you have this thing that looks like a ghost tissue," Taylor says.

The research team then repopulated the "ghost tissue" with new heart cells taken from newborn and neonatal rats, fed them a nutrient-rich solution and left them in the laboratory to grow.

Four days later, the hearts started to contract.

 CONTRACTIONS

The researchers used a pacemaker to co-ordinate the contractions. They hooked up the hearts to a pump so they were being filled with fluids and added a bit of pressure to simulate blood pressure.

Eight days later, the hearts started to pump.

While there have been advances in generating living heart tissue in the laboratory, this is the first time an entire, three-dimension bio-artificial heart has been brought to life.

"We recognised that nature has created the perfect scaffold and wondered whether there is a way in the lab to give nature the tools and get out of the way," Taylor says.

The researchers chose immature heart cells because they thought these were most likely to work.

"The hope ultimately, although we've got a ways to go, is that we could take a scaffold from a pig or a cadaver and then take stem or progenitor cells from your body and actually grow a self-derived organ," Taylor says.

LIMITATIONS

 

Professor Wayne Morrison, director of the  Bernard O'Brien Institute of Microsurgery  in Melbourne, says the study is "novel and interesting".

However, Morrison, whose research group last year successfully grew beating heart muscle from adult stem cells inside a rat, says the scientists now need to show this research can be transferred into living animals.

"Another limitation is that in order to add cells back to the heart they needed to inject the structure with 50-75 million cells," he says.

Morrison says at least 100 rat hearts would be needed to make one artificial heart under this process.

"This was also a criticism of our own research, which needed about 10 hearts," he says.

"I think there is a long way to go for all of us in terms of where we go to get the cells that ultimately would make a real human heart.

"We can't just access 100 other hearts as they have done here."