Researchers Grow Miniature, Working Human Livers in the Lab

Decellularized Hearts
A heart is washed of its cells, leaving behind only the structural skeleton that gives the tissue its shape.Courtesy of University of Minnesota

Research presented at Sunday's American Association for the Study of Liver Diseases in Boston marked a preliminary but potentially groundbreaking development in the search for the lab-engineered organs of the future. Scientists at the Institute for Regenerative Medicine at Wake Forest University Baptist Medical Center have engineered the first functioning miniature livers from human liver cells ever created in a lab setting. The technique could open up new avenues for engineering a range of vital tissues in the lab.

To create the mini livers, the team took animal livers and washed out the animal cells with a mild detergent, a method known as "decellularization" that leaves behind only the cellular scaffold that gives the organ its structure. They then piped human cells into place via the natural vessel network that remains in the liver after the decellularization process. Connected to a bioreactor – a machine that mimics the conditions inside a living body by feeding nutrients and oxygen to the organ – the human cells began to form human liver tissue, albeit in miniature stature.

The final goal of this research, of course, is to find a means to engineer donor livers in the lab to close the supply-demand gap between those who need livers for transplant and the shortage of donor organs on hand. But engineered livers could also be used to test drugs for safety and efficacy in the lab.

Animal livers have been created in the lab using this process before, but it was never clear if researchers could do the same with human cells. Now that they've demonstrated the ability, the next step will be to get one into a living animal and see how it functions. Then, ostensibly, they'll try to grow larger, more complex organs equivalent to full-grown human organs. As such, the era of made-to-order livers is still a ways off. But this important step forward for bio-engineering could contribute not only to lab-grown livers, but also to other engineered tissues that are in short supply, like kidneys or pancreases.