Brazilian researchers, based in São Paulo, claim to have used bioprinting to make liver spheroids – miniature versions of the liver – from human blood cells. These miniature organs are said to perform all the functions expected of them, namely the production of vital proteins, the storage of vitamins and the secretion of bile. Liver tissue has been obtained in 90 days: a breakthrough that could become an alternative to organ transplantation, which sometimes takes too long due to a lack of donors.
In the field of bioprinting, all the attention is focused on the creation of functional organs: it is worth noting the progress made this year, notably by Dr. Tal Dvir’s team, which succeeded in bioprinting a heart composed of blood vessels and tissues. The challenge now is to keep these organs alive over time. One of the first companies to look into bioprinting liver tissue was Organovo. Brazilian researchers are now joining the race with their 3D printed mini-livers.
The team would have succeeded in creating a small liver by bioprinting | Credits: Daniel Antonio/Agência FAPESP
Conducted at the Human Genome and Stem Cell research center hosted at the University of São Paulo, the study is the result of a combination of several bioengineering techniques such as pluripotent stem cell culture and cell reprogramming with bioprinting. The researchers used the Inkredible bioprinter from Cellink, one of the industry’s leading manufacturers, to create their liver tissue. What is different from the other work done so far is that the cells were pooled in the bioink before being extruded. Ernesto Goulart, co-author of the study, explains: “Instead of printing individualised cells, we developed a method for grouping them before printing. These clusters of cells, or spheroids, make up the tissue and maintain its functionality much longer.” This method avoids the gradual loss of contact between cells and thus the loss of functionality of the tissues.
Bioprinting a small liver in 90 days
Researchers say it took 90 days to develop these small, bioprinted livers from patient blood collection to tissue production. The first step being to reprogram the patient’s blood cells into induced pluripotent stem cells. These are then differentiated into liver cells and their spheroids can then be integrated into the bioink. The printing process can now begin. The cultivation of the 3D printed cell structures took 18 days.
The liver bioprinting process | Credits: Agência FAPESP
To test this method, the scientists explain that they bioprinted three different small livers from the cells of three volunteer patients. They studied the functionalities of the liver as well as the maintenance of cell contact. Goulart concluded: “Our spheroids functioned much better than those obtained from single-cell dispersion. As expected, during maturation the markers of liver function were not reduced.”
The researchers say this experiment could be done on a larger scale and on other organs. Good news for the medical sector! In the meantime, you can find the entire study published in Biofabrication.
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