BOSTON, June 16 (UPI) -- U.S. scientists say they've developed a technique that might some day allow the growth of transplantable replacement livers.
Massachusetts General Hospital researchers in Boston said they've used structural tissue from rat livers as scaffolding to grow tissue regenerated from liver cells.
"Having the detailed microvasculature of the liver within a biocompatible, natural scaffold is a major advantage to growing liver tissue in a synthetic environment," said research associate Basak Uygun, the paper's lead author. She said the technique of "decellularizing" organs leaves the vascular system intact, facilitating repopulation of the structural matrix and the subsequent survival and function of the introduced liver cells.
The scientists said their procedure is a refinement of an approach to re-engineering replacement rat hearts reported in 2008 by University of Minnesota researchers. Since liver tissue is more delicate than heart tissue, the team developed "a gentler way" of flushing living cells from the liver's structural matrix.
They then reintroduced hepatocytes, the cells that perform most of the liver's primary functions, and those cells penetrated the vascular network and became embedded in the matrix, leaving major vessels clear to carry the blood supply.
The repopulated matrix displayed normal liver function for up to 10 days in culture, and recellularized grafts were successfully connected to the circulation of live rats with minimal cellular damage and normal hepatocyte function.
"Even though this is very exciting and promising, it is a proof-of-concept study only," researcher Korkut Uygun, the paper's senior author, said. "Much more work will be required to make long-term functional liver grafts that can actually be transplanted into humans."
The study appears in the early online edition of the journal Nature Medicine.