Innovation



Researchers create
artificial beating heart


 

University of Minnesota researchers have created a beating heart in the laboratory.

By using a process called whole organ decellularisation, scientists from the University of Minnesota Center for Cardiovascular Repair grew functioning heart tissue by taking dead rat and pig hearts and reseeding them with a mixture of live cells. The research was vpublished online in the 13 January 2008 issue of Nature Medicine.

“The idea would be to develop transplantable blood vessels or whole organs that are made from your own cells,” said Doris Taylor, PhD, director of the Center for Cardiovascular Repair, Medtronic Bakken professor of medicine and physiology, and principal investigator of the research.

While there have been advances in generating heart tissue in the lab, creating an entire 3-dimensional scaffold that mimics the complex cardiac architecture and intricacies, has always been a mystery, Taylor said.

It seems decellularisation may be a solution – essentially using nature’s platform to create a bioartifical heart, she said.

Decellularisation is the process of removing all of the cells from an organ – in this case an animal cadaver heart – leaving only the extracellular matrix, the framework between the cells, intact.

After successfully removing all of the cells from both rat and pig hearts, researchers injected them with a mixture of progenitor cells that came from neonatal or newborn rat hearts and placed the structure in a sterile setting in the lab to grow.

The results were very promising, Taylor said. Four days after seeding the decellularised heart scaffolds with the heart cells, contractions were observed. Eight days later, the hearts were pumping.

“Take a section of this ‘new heart’ and slice it and cells are back in there,” Taylor said. “The cells have many of the markers we associate with the heart and seem to know how to behave like heart tissue.”

“We just took nature’s own building blocks to build a new organ,” said Harald C. Ott, MD, co-investigator of the study and a former research associate in the Center for Cardiovascular Repair, who now works at Massachusetts General Hospital. “When we saw the first contractions we were speechless.”

Researchers are optimistic this discovery could help increase the donor organ pool. In general, the supply of donor organs is limited and once a heart is transplanted, individuals face life-long immunosuppression, often trading heart failure for high blood pressure, diabetes, and kidney failure, Taylor said.



Researchers hope that the decellularisation process could be used to make new donor organs. Because a new heart could be filled with the recipient’s cells, researchers hypothesize it’s much less likely to be rejected by the body. And once placed in the recipient, in theory the heart would be nourished, regulated, and regenerated similar to the heart that it replaced.



 D
ate of upload: 25th January 2009

                                  
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