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Queen of Hearts

February 14, 2011

Eva Gusnowski

Valentine’s Day is here again.  Millions of heart-shaped boxes, candies and valentines are given out on this day every year.  But what if we could give a heart to someone who really needed it?  And I don’t just mean any heart; I mean their heart.

 

        Eva Gusnowski, bioartificial heart, decelluarization



Every year there are at least 4000 people in Canada that require an organ transplant.  Last year, only 1803 transplants were performed across the country and 195 people died while they were waiting for an organ.  In the United States, at least 3000 people are consistently on the waiting list for heart transplants alone, but only 2000 donor hearts are available for transplant every year.  In addition to the small number of organs available, transplants are also limited by infectious diseases, blood type and compatibility; further reducing the pool of suitable donor organs.

Many scientists have now begun to investigate how a heart can be repaired after its been damaged so transplants might be altogether unnecessary.  In a 2007 study, human embryonic stem cells were induced to form myocardiocytes (heart muscle cells).  In addition to a cocktail that promotes cell growth, the myocardiocytes were then injected into rat hearts that had been damaged by infarction (which means tissue death due to a lack of oxygen).  After transplantation, the human-derived myocardiocytes were able to form muscle grafts in the damaged heart, attenuated heart failure and helped the hearts to retain global contractile function.  This is obviously a potential method to help damaged hearts, but what if the level of damage is too great to be rescued by this method and they absolutely need a new heart?

This leads us to one of the most exciting areas of organ transplant research.  In 2008, a study was published out of the University of Minnesota in Dr. Doris Taylor’s lab that described the generation of a bioartificial heart.  That’s right; they made a functional heart in a lab.
 

        Eva Gusnowski, bioartificial heart, decelluarization

 

In order for organs to form properly, they need a scaffold to grow on.  During human development the cells make the scaffold themselves.  Cells secrete a jelly-like scaffold called a matrix so that they can remain attached and maintain the organ’s structure.  The process of generating bio-artificial hearts starts by obtaining a cadaver heart.  In this case, the rat heart was used again.  All of the cells were washed away using strong detergents, leaving the jelly-like matrix in the shape of a heart (FYI: these are often called “ghost hearts” because they are transparent).  These decellularized hearts were then seeded with heart cells obtained from newborn mice and left to grow.

Amazingly, the seeded hearts formed beating hearts within 8 days. Over a period of 28 days, the hearts were analyzed and were found to function normally as a naturally derived heart does.  (To see this unreal process live, go to http://www.youtube.com/watch?v=j9XzN0-TQZc)  The ultimate goal is to decellularize cadaver hearts and seed them with an individual’s own heart cells.  This would give a heart that is made to match that individual’s blood type and other markers, essentially eliminating the need for anti-rejection drugs during transplantation, and also getting rid of a lot of problems associated with blood type and pathogens. 

And it doesn’t even stop there.  The same lab is applying this technique to pig hearts, showing this technology can be scaled to hearts close to the size and complexity of human hearts.  They are also currently investigating the generation of livers and other solid organs, which means we have the potential to have personalized organs in the very near future.

 

        Eva Gusnowski, bioartificial heart, decelluarization



So today when you give your sweetie a valentine and drink that glass of wine, give a cheers to our homies at the University of Minnesota and to the Queen of Hearts.  After all of that chocolate, we all might need their help some day.

BE HEARD

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