Israeli researchers have created a mini heart of human tissue with a 3D printer. Their development was also presented in the journal „Advanced Science“. But how far is research really? Is the heart of the printer actually already an alternative to organ donation?
Decisive for 3D printing of organs or organ-like bodies is the material. The Israeli researchers have been working with pluripotent stem cells for their study. First, they extracted adipose tissue – fat cells – and used it to make heart cells in several steps. What sounds like science fiction is nothing new in the professional world. For this one reprograms these fat cells back to stem cells. In other words: the clock is reset and from already specialized cell types all-rounders are made again which can develop into every cell type. In this case, heart muscle cells and endothelial cells that line blood vessels were grown from fat cells.
Cells + hydrogel = „Biotinte“
These cells were then each mixed with a viscous gel, a kind of „biotin“. From cardiac muscle ink and blood vessel ink, a 3D printer has then printed layer by layer a structure that roughly resembles that of a heart: heart muscles with blood vessels. But it must be noted that what has been created is far from being a human heart. It’s about the size of a human fetus – not that of a full-blown heart. In addition, the structure does not work yet: The „heart“ can not contract synchronously – so it does not strike. Similar approaches already existed.
Also supporting tissue from patient cells
However, what is new in the approach of the Israeli researchers: The hydrogel they use, the supporting tissue for the „heart“, the researchers also produced from the samples of the donor. So they were able to produce the organ-like structure, with a few additions, entirely from human tissue of the cell donor. And this opens up the perspective that at some point organs can be produced that do not cause rejection reactions, as is known, for example, from donor organs.
This also applies to the „cardiac patches“, a kind of patch that the Israeli researchers tested in the study. Such patches can be used as part of the therapy of a heart attack to colonize dead tissue again with fresh cells. And the researchers have also made these patches from the body’s own tissue.
Operable organs from the printer
There are already promising approaches for the cultivation of individual pieces of tissue from patient cells, such as skin grafts. But it can still take years before it can actually print ready organs. Because the interlocking of different functions of a complex organ like heart or a kidney is not easy to imitate. The authors of the study say for themselves: In order to do so, more cells must be processed in the next steps.
Likewise, the maturation of the organ as well as the exact imitation of its architecture are still open construction sites. The complex interplay of different cell types, which, in the course of evolution, perfectly matches the complexities of different cell types that ultimately make a heart beat, still poses a challenge to science.
