Researchers from the University of Pittsburgh have successful grown miniature, mature livers from human tissue cells, which were also then successfully transplanted to rats. After the transplants, these livers have survived in their hosts for 4 days. Results of this research was recently published in Cell Reports.

These lab-grown livers produce bile acids and urea just like normal livers do, with exception that they were grown using induced pluripotent stem cell. Even though it takes about two years for a liver to mature in nature, researchers, headed by Alejandro Soto-Gutierrez, associate professor of Department of Pathology of the University of Pittsburgh were able to do in under a month.

Researchers have received miniature livers by reprogramming human skin cells into induced pluripotent stem cells, forced them to differentiate into various liver cells and then grafted them into rat livers that were stripped of cells.

The final part of the study was to transplant the livers into five immunosuppressed rats, bred to reduce rates of organ rejection. After four days, researchers checked the status of the rats. All transplants had problems with blood flow within and around transplants, however, livers were working – blood samples from rats contained human liver proteins.

Doctor Soto-Gutierrez thinks that the results of this study are positive and are the first step towards potential growth of organs for transplantation in labs.

“The long-term goal is to create organs that can replace organ donation, but in the near future, I see this as a bridge to transplant.” – said Soto-Gutierrez.-  For instance, in acute liver failure, you might just need hepatic boost for a while instead of a whole new liver”

Although these results were promising, there are still challenges that need to be addressed in future studies such as long-term survival and safety issues.