Several diseases, counting hepatitis & cirrhosis, can result in liver failure. And many people suffering from these diseases are just waiting for a liver transplantation. But the sad truth is that only a few livers are available. In order to tackle this shortage, a research team from Rockefeller University, Boston University, and MIT has discovered a new method to engineer liver tissue. They have done this by organizing small subunits that enclose 3 cell types inserted into a biodegradable tissue scaffold. The researchers, in a mice study with impaired livers, found that after being set in the abdomen, the small structures extended 50-fold and had the potential to execute normal liver tissue functions.
So, according to the researchers, this is a ray of hope for several individuals that experience chronic liver disease but do not qualify for a liver transplant. The present work is anchored on the earlier work done by Sangeet Bhatia’s lab. They, in 2011, had designed an engineered tissue scaffold that could be inserted into mouse’s abdomen. There, the liver cells would incorporate with the circulatory system of the mouse, permitting it to get a blood supply and initiate executing normal liver functions.
Nonetheless, those implants comprised less than 1 Million hepatocytes, whereas a healthy human liver has approximately 100 Billion hepatocytes, and Bhatia considers that at least 10–30% of that figure would be required to assist most patients. Thus, to increase their hepatocyte count, the team decided to take benefit of a vital attribute of liver cells—that they can proliferate to produce new liver tissue. The liver has the potential of regenerating and it is the mature cell that divides, devoid of an intermediate stem cell, which is extraordinary.
The team developed microfabricated structures that integrate with spherical “organoids” composed of fibroblasts and hepatocytes, as well as endothelial cell cords, which are blood vessels’ building blocks. These 2 forms of structures are systematized into patterns and entrenched into fibrin. After the implantation of the constructs into a mouse, they get regenerative signals from the adjacent surroundings. These signals, which comprise enzymes, molecules & growth factors, are naturally made when liver injury ensues. These signals activate the endothelial cells to produce blood vessels and to liberate factors that activate hepatocyte proliferation, leading to a 50-fold extension of the original tissue.
The liver performs numerous roles for the body, the majority of which are associated with metabolism regulation, detoxification of damaging constituents, and bile production. Validation of the implanted human livers demonstrated that patterns of all of these functions were taking place normally within the host mice. At present, the researchers are also attempting to explore the other aspects of this study.