Scientists from Tel Aviv University printed an artificial heart by using human adipose tissue recently. Although it is only a miniature prototype, it is the first artificial heart designed and printed successfully by human, which contains cells, blood vessels, ventricles and atria.
This 3D-printed heart can be seen as a breakthrough brought about by the combination of different disciplines including biology, material science, computer science and so on. Scientists firstly extracted some adipose tissue from human body and separated the “cellular” and “non-cellular” components. These cells were later used to induce pluripotent stem cells, while the non-cellular components such as collagen and glycoprotein were used to synthesizing “individualized gels”, serving as the “ink” of 3D printing.
Researchers found out that the gel made of its own material provided a good environment for the development of stem cells. In these gels, stem cells can differentiate into heart cells and endothelial cells efficiently. Tissue made of these cells can avoid rejection in allotransplantation effectively for the reason that all the materials come from patients themselves.
After differentiating the cells, the researchers went a step further and began using this method to print heart tissue and organs. By using CT scanning technique, they sketched out the general structure of the heart, which includes the shape of the heart, the sizes of the ventricles and atria and the direction of the major blood vessels. For networks of small blood vessels that can’t be captured by CT scans, the researchers used mathematical models to calculate the oxygen consumption in different regions and to distribute the course of the vessels properly. With the assistance of computer, a more complete network of blood vessels was obtained, which can be used in actual printing.
Limited to current technology, the printed heart is almost of the size of a cherry, about the size of a rabbit’s heart. This artificial heart is with complete structure and the cells of it can contract. However, it can not pump like a normal heart. And that’s where the researchers are headed next.
Cardiovascular disease is the most dangerous killer of humans currently. And a heart transplant is almost the only option for patients with severe disease. However, many patients die during their long waiting for the suitable organs. If 3D printing can be applied in human organ transplantation, the severe situation will be changed.