Dead hearts beat again

US researchers say they have coaxed hearts from dead rats to beat again in the laboratory and said the discovery may one day lead to customized organ transplants for people.

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

Her study, which appeared on Sunday in the journal Nature Medicine, offers a way to fulfil the promise of using stem cells - the body's master cells - to grow tailor-made organs for transplant.

How it was done
Taylor and colleagues used a process called decellularisation to wash away existing cells from the hearts of dead rats while leaving the basic collagen structure intact.

They injected this gelatine-like scaffold with heart cells from newborn rats, fed them a nutrient-rich solution and left them in the lab to grow.

Four days later, the hearts started to contract.

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.

"I have got to tell you, that was the home run," Taylor said in a telephone interview.

Healing hearts
Like many researchers, Taylor and colleagues had been working on a stem cell therapy to try to heal hearts damaged by heart attacks.

A British team last month said they generated mature, beating heart cells from embryonic stem cells that could be used to make a heart patch.

Others have tried injecting heart stem cells directly into the scarred heart in the hopes of regenerating damaged tissue.

The Minnesota team took another approach.

"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 said.

She and colleague Dr Harold Ott, who is now at Massachusetts General Hospital, knew that decellularisation already had been used in making tissue heart valves and blood vessels and decided to try it on whole organs.

They did the process with rat and pig hearts. But they only reported on the regeneration of the rat hearts.

A ghost tissue
"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 said.

The scaffold is made up of collagen, fibronectin and laminin.

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," she said.

Taylor said the process could be used on other organs, offering a potential new source of donor organs. It also could lead to organs that, in theory, would be less likely to be rejected by the body.

"This is an ingenious step towards solving a massive problem," Dr Tim Chico of Britain's University of Sheffield said in a statement. "This study is very preliminary, but it does show that stem cells can regrow in the 'skeleton' of a donor heart." – (Reuters Health)

Read more:
Stem cell patch to treat heart
Another stem cell breakthrough

January 2008

We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For 14 free days, you can have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today. Thereafter you will be billed R75 per month. You can cancel anytime and if you cancel within 14 days you won't be billed. 
Subscribe to News24
Voting Booth
The ANC's leadership race is heating up. Who do you think will be elected party president at Nasrec in December?
Please select an option Oops! Something went wrong, please try again later.
Results
Nkosazana Dlamini-Zuma has got it in the bag
6% - 203 votes
I foresee a second term for Cyril Ramaphosa
81% - 2613 votes
Don’t discount a Zweli Mkhize win
12% - 397 votes
Vote
Rand - Dollar
18.00
-0.9%
Rand - Pound
19.92
-2.5%
Rand - Euro
17.62
-1.4%
Rand - Aus dollar
11.67
-0.3%
Rand - Yen
0.12
-0.7%
Gold
1,662.28
+0.1%
Silver
18.77
-0.7%
Palladium
2,221.00
+3.3%
Platinum
870.50
+0.5%
Brent Crude
89.32
+3.4%
Top 40
56,921
-0.9%
All Share
63,264
-0.9%
Resource 10
59,793
+3.3%
Industrial 25
76,769
-2.2%
Financial 15
13,707
-2.8%
All JSE data delayed by at least 15 minutes Iress logo
Editorial feedback and complaints

Contact the public editor with feedback for our journalists, complaints, queries or suggestions about articles on News24.

LEARN MORE