Tel Aviv University researchers have "printed" the world's first three dimensional (3D) vascularised engineered heart using a patient's own cells and biological materials. Their findings were published on 15 April in a study in Advanced Science.
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.
"This is the first time anyone anywhere has successfully engineered and printed an entire heart replete with cells, blood vessels, ventricles and chambers," said Prof. Tal Dvir of TAU's School of Molecular Cell Biology and Biotechnology, who led the research for the study.
Heart disease is the leading cause of death among both men and women in the United States. Heart transplantation is currently the only treatment available to patients with end-stage heart failure. Given the dire shortage of heart donors, the need to develop new approaches to regenerate the diseased heart is urgent.
"This heart is made from human cells and patient-specific biological materials. In our process these materials serve as the bioinks, substances made of sugars and proteins that can be used for 3D printing of complex tissue models," Prof. Dvir said in a 15 April press statement.
In early 2017, a team of biomedical engineering researchers, led by the University of Minnesota created a laser 3D-bioprinted patch to address the issue and help heal the scarred heart tissue after a heart attack. When the cell patch was placed on a mouse following a simulated heart attack, the researchers saw significant increase in functional capacity after just four weeks. The patch was made from stem cells and structural proteins (that do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs) belonging to the heart, it became part of the heart and was absorbed into the body, requiring no further surgeries.
According Avir, while people have managed to 3D-print the structure of a heart in the past, they have not done so with cells or with blood vessels. "Our results demonstrate the potential of our approach for engineering personalized tissue and organ replacement in the future," he added.
For the research, a biopsy of fatty tissue was taken from patients. The cellular and a-cellular materials of the tissue were then separated. While the cells were reprogrammed to become pluripotent stem cells, the extracellular matrix (ECM), a three-dimensional network of extracellular macromolecules such as collagen and glycoproteins, were processed into a personalized hydrogel that served as the printing "ink". After being mixed with the hydrogel, the cells were efficiently differentiated to cardiac or endothelial cells to create patient-specific, immune-compatible cardiac patches with blood vessels and, subsequently, an entire heart.
The researchers are now planning on culturing the printed hearts in the lab and "teaching them to behave" like hearts, according to Prof. Dvir. They then plan to transplant the 3D-printed heart in animal models. He hopes that in the next decade, there will be organ printers in the finest hospitals around the world, and these procedures will be conducted routinely.
3D printing belongs to a class of techniques known as additive manufacturing, or building objects layer by layer. Today, 3D printers not only make jewellery and toothbrushes but also football boots, racing-car parts, custom-designed cakes, human organs, houses, aeroplane parts and even more efficient lithium-ion batteries. And yes! They even provide blueprints for 3D-printed guns. Five years ago, Indian plastic surgeons at the Jawaharlal Institute of Postgraduate Medical Education and Research (Jipmer) in Puducherry restored the deformed skull of a three-year-old girl to its original shape with the help of a 3D printer.