Researchers at MIT, Rockefeller University and Boston University have developed a new way to create liver tissue from the "seeds" of the future organ, implanted into the patient's diseased liver. "Seeds" increase tenfold and perform the functions of a normal liver.
“Our goal is to one day apply this technology to increase the number of organ transplants, which are now very limited,” said Professor Sangeeta Bhatia, senior author of the Science Translational Medicine article. However, there is no question of a real transplant in this case. The method involves updating the tissues of the patient's diseased liver. The modified liver will make life easier for millions of patients suffering from chronic diseases, but not eligible for organ transplants.
In 2011, Professor Bhatia's laboratory developed a shell the size and shape of a contact lens, which was implanted into the abdominal cavity of a mouse during testing. There, artificially grown liver cells integrate with the circulatory system and begin to act like a normal liver. However, the number of hepatocytes (liver cells) in the implant was less than 1 million, while there are about 100 billion in a healthy human liver. For the normal functioning of the implant, at least 10 - 30% of this number is required, Bhatia said.
Many diseases can lead to liver failure, including hepatitis and cirrhosis. More than 17,000 Americans are on the waiting list for liver transplants, but there are significantly fewer organs available for transplantation.
Therefore, scientists took advantage of the liver's ability to regenerate its tissues without the intervention of stem cells. They developed spherical organelles from hepatocytes and fibroblasts, as well as endothelial cells, combined them into structures and encased them in a sheath of fibrin, a protein that is involved in the process of blood clotting.
Once this structure enters the mouse, it receives a signal to begin regeneration, including growth factors, enzymes and molecules that are produced when the liver is damaged. The signals stimulate the formation of blood vessels from endothelial cells and the growth of hepatocytes, which leads to an increase in the original tissue size by 50 times, according to MIT News.
“The idea is that this is an organ seed, and it needs to be made so that it can respond to regenerative signals, but it will be the minimum unit of what should come out in the end,” says Bhatia. "The amazing thing is that the architecture of the resulting tissue is a lot like the architecture of a real liver."
A functional liver was raised by Los Angeles scientists last year. To do this, they used stem cells and progenitor progenitor cells. The implants are not similar in shape to a real liver, but they perform all its functions.
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