How 3-D Printing Can Help Mend a Broken Heart

A false-color scanning electron micrograph (SEM) of a blood clot protruding from an arterial entrance in a heart chamber. This type of clot, known as coronary thrombosis, is the usual cause of myocardial infarction (heart attack). P. Motta/G. Macchiarelli/Sapienza University/Science Photo Libary/Getty

Each year, more than 700,000 people suffer myocardial infarction, aka a heart attack. Thanks to medical advances, there are myriad ways for a doctor to get the blood properly pumping and save a person's life. A cardiologist might give a patient medication to clear or loosen blockages. Or a doctor might insert a catheter to remove the clot, or place stents in the artery so it stays open.

These interventions have vastly improved survival rates, but they don't heal the damage caused by a cardiac event. The heart is really just one big muscle, and trauma to any muscle does some damage, which becomes scar tissue. Scar tissue on the heart means it functions far less optimally, which eventually leads to heart failure.

Short of a transplant, there isn't a long-term option to fix a damaged ticker. But a team of researchers say they've come up with a high-tech solution that could revolutionize cardiology. Using 3-D printing technology, Brenda Ogle, an associate professor of biomedical engineering at the University of Minnesota-Twin Cities, has created a patch a doctor could apply to mend a patient's broken heart.

"The concept is to imprint proteins that are native to the body," says Ogle. "We've used stem cell–derived cardiac muscle—cardiac myocytes—and actually mixed those with other cell types needed for blood vessels." This, she says, prevents what would otherwise happen naturally: The formation of a different type cells known as fibroblasts, which secrete scar tissue.

Ogle and her team of 3-D printing experts, clinical cardiologists and stem cell engineers have successfully tried the patch on mice. First, the team induced cardiac arrest in the rodents. When they then placed the cell patch on a mouse, researchers saw a significant increase in the functional capacity of the organ after just four weeks. "We generated the continuous electric signal across the patch, and we can pace it: We can increase the frequency of beating up to three hertz, which is similar to a mouse heart," says Ogle who, this past January, published the findings of their experiment in Circulation Research, a journal from the American Heart Association.

The results of the experiment were so inspiring that in June 2016 the National Institutes of Health awarded her team a grant of more than $3 million, so they can now give pigs heart attacks and fix them with the patch. However, it will take some time to see their innovation in surgical departments, since using biological products such as cells requires a long regulatory process and, of course, quality assurance.

"The replacement of muscle has been the holy grail for some time," says Ogle. "Now we finally have the ability to take stem cells out of the body and develop the protocols to do that."