Brazilian Liver
Brazilian scientists have printed a small copy of the liver
Using human blood cells, researchers from the University of Sao Paulo were able to obtain organoids - "mini–livers" - that perform all the typical functions of the liver: the production of vital proteins, the storage of vitamins and the excretion of bile. The innovation makes it possible to produce liver tissue in the laboratory in just 90 days and in the future may become an alternative to organ transplantation, the press service of the FAPESP research foundation reports.
The scientists presented a description of the development in an article published in Biofabrication (Goulart et al., 3D bioprinting of liver spheroids derived from human induced pluripotent stem cells sustain liver function and viability in vitro).
To obtain an artificial organ, the researchers used several bioengineering methods: "reprogramming" cells, culturing pluripotent stem cells (these cells can turn into any kind of cells) and three-dimensional bioprinting. Thanks to this strategy, the tissue printed on the bioprinter retained liver function longer than in previous experiments.
The innovative part of the study is how the cells were incorporated into the bio-ink used to print tissue on a 3D printer. Instead of printing individual cells, the scientists grouped them into separate "clumps" before printing. Thanks to these "clumps" of cells, or spheroids, the contact between cells in the tissue is not lost over time, and therefore its functionality is preserved, the authors note. Spheroids were formed during differentiation when pluripotent cells transformed into liver tissue cells (hepatocytes, vascular wall cells and mesenchymal cells).
"There are still many stages to go through before we get a full-fledged organ. But we are on the right path to very promising results. In the very near future, instead of organ transplantation, it may be possible to take cells from a patient and "reprogram" them to make a new liver in the laboratory. Another important advantage: zero probability of rejection, given that the cells belong to the patient himself," said Mayana Zatz, director of the Center for Human Genome and Stem Cell Research, one of the authors of the work.
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