Researchers at Tel Aviv University say their ‘major medical breakthrough’ will advance possibilities for transplants
Cardiovascular disease is the world’s leading cause of death, according to the World Health Organization, and transplants are currently the only option available for patients with end-stage heart failure. But the number of heart donors is in short supply and many die while waiting. Even when they do benefit, they can fall victim to their bodies rejecting the transplant — a problem a team of researchers at Tel Aviv University is seeking to overcome.
The Tel Aviv team has unveiled the world’s first complete 3D printed heart with human tissue and blood vessels calling it “a major breakthrough,” advancing the possibility for transplants. “Using the patient’s own tissue was important to eliminate the risk of an implant provoking an immune response and being rejected,” according to Tal Dvir, who led the research and is senior author of the study published in the journal Advanced Science.
Dvir says this marks “the first time anyone anywhere has successfully engineered and printed an entire heart replete with cells, blood vessels, ventricles and chambers. Until now, scientists in regenerative medicine — a field positioned at the crossroads of biology and technology — have been successful in printing only simple tissues without blood vessels.” When asked to sum up this groundbreaking accomplishment, he states, “Our results demonstrate the potential of our approach for engineering personalized tissue and organ replacement in the future.”
So, you may wonder, where do you begin when 3D printing a living heart? The first step involves taking a biopsy of the fatty tissue that surrounds the abdominal organs from the patient. Researchers then separate the cells in the tissue from the rest of the contents, namely, the extracellular matrix linking the cells. After which, the cells are reprogrammed to become stem cells and the matrix is processed into a personalized hydrogel that serves as the printing “ink.”
When mixed with the hydrogel, the stem cells differentiate into cardiac or epithelial cells, creating patient-specific, immune-compatible cardiac patches with blood vessels, which later become an entire heart. “At this stage, our 3D heart is small, the size of a rabbit’s heart,” added Dvir. “But larger human hearts require the same technology.”
He also notes, “The biocompatibility of engineered materials is crucial to eliminating the risk of implant rejection, which jeopardizes the success of such treatments. Ideally, the biomaterial should possess the same biochemical, mechanical and topographical properties as the patient’s own tissues. Here, we report a simple approach to 3D-printed thick, vascularized and perfusable cardiac tissues that completely match the immunological, cellular, biochemical and anatomical properties of the patient.”
Next, the researchers plan to train the hearts to behave like hearts, Dvir explained, “The cells need to form a pumping ability; they can currently contract, but we need them to work together.” If researchers are successful, they plan to transplant the 3D-printed heart in animals and, after that, humans.
Although we may be years away from having organ printers in the finest hospitals around the world to enable these procedures to be conducted routinely, this is certainty a groundbreaking step toward engineering customized organs that can be transplanted with less risk of rejection.
More than 113,000 people are currently on the national transplant list. And with a shortage of donors, this means that about 20 people die every day while waiting for an organ, according to the U.S. Department of Health.