Cardiac researcher Doris Taylor discovered a way to make hearts more accessible in the public health field through a process known as decellularization.
Credit: Courtesy of Flickr.
"The Future of Heart Transplantation." Picture courtesy of Flickr.
Cardiac researcher Doris Taylor discovered a way to make hearts more accessible in the public health field through a process known as decellularization.
That sparkly heart emoji on your smartphone is supposed to be symbolic for “shiny and new love.” Thanks to Doris Taylor, we might have shiny new hearts for those waiting on the donor list.
In 2005, cardiac researcher Doris Taylor had an idea that could tackle congestive heart failure, a condition roughly 62 million people are living with in the U.S. alone. Heart failure, a condition in which the heart is no longer able to pump blood through the body, requires a patient to undergo a heart transplant. Unfortunately, a new heart is a tall order for the public health system—there’s a long waiting line for donor hearts. Even if the patient is able to live long enough to receive a donor heart, the patient’s immune system may reject the donated organ. A donated organ typically has the original owner’s antigens, natural proteins secreted by certain cells. Sometimes, a patient’s immune system can mistake the antigens for a virus, and attack the life-saving organ.
So, Taylor had some difficult challenges to overcome: where would she get the hearts, and how would she alter them so the patient’s body would accept them? Well, the first part of the question was the easiest.
Creating the Ghost Heart
Taylor rinsed rat hearts with detergent until the blood vessels and color drained out of them, leaving the heart’s skeletal tissue behind. This skeletal tissue, when drained of blood, is white and is what gives a “ghost heart” its name. By removing the blood vessels, she also removed the antigens that the organ recipient’s body might reject.
However, there is another problem: a heart cannot function without cells. So, Taylor took heart cells from newborn rats and injected them into the ghost heart. She used stem cells because they are undifferentiated cells that have the capability to turn into any cell they need to, like a heart, liver, or kidney cell. Eight days later, the rat’s heart began to beat on its own. Not only had Taylor created the first functioning heart in a lab, she can ensure the heart will be compatible with the recipient.
While she proved the procedure could work in rats, Taylor eventually wants to use the procedure on pig hearts, which are more similar in structure and size to human hearts.
However, the experiment isn’t over yet. Taylor must find a way to ensure that this new heart will be able to pump 7,000 liters of blood throughout the body every day without any help. Not only this, but if the recipient is young, the heart needs to be able to grow.
The trickiest of them all—Taylor has to find a way to incorporate the new heart with the maze of blood vessels in the recipient’s body. After all, a heart is no good if it can’t pump any blood!
Is this the beginning of the end to the organ shortage?
As the number of patients on the wait-list rises, the number of available organs decreases. Advances in medical care have lengthened the lifespans of potential organ donors, and family members are refusing to give consent. Can the ghost heart experiment eventually be used on human hearts? Can it be replicated for other organ transplants, like kidneys or livers? What political impacts could this medical breakthrough have on our society?
When it comes to what we know about the heart, we have to give some credit to Charley’s hero of course: Leonardo da Vinci. Although he was an amateur scientist, Leonardo’s original drawings and theories of how the heart functions were far more detailed and better understood than would be suggested for his time. For example, he knew blood flows through the heart when arterial valves open and close. This is a concept that even modern cardiologists get wrong!
Unfortunately, Leonardo’s dissection of a human heart, his anatomical drawings and detailed notes were never published in his lifetime. In fact, they weren’t discovered again until about 250 years after his death, so this knowledge was lost. Medicine has been working to catch up ever since.
What else do you think we would know about the heart had we discovered Leonardo’s work earlier?
