Instead of waiting years in line for a donated organ, what if sick patients could simply build a fresh liver from scratch?
The day when organs can be printed as easily as newspapers remains far in the future. But a San Diego company has taken another small step toward making it a reality.
Monday, at the Experimental Biology conference in Boston, Organovo announced that it has assembled three-dimensional liver tissue from living human cells, and that this tissue functions like livers inside human bodies.
"Liver cells in particular need to be in a three-dimensional environment to function properly," said Organovo's Chief Technology Officer Sharon Presnell, referring to a persistent problem in pharmaceutical research. It's a problem of depth perception.
When researchers need to test potential drugs on human tissue, they currently rely on flat cell cultures. The problem is, two-dimensional tissue just doesn't work like real organ tissue. As a result, a lot of early drug experiments deliver results that won't be duplicated in humans.
To address that problem, Organovo set out to make a three-dimensional model of the human liver. They do that by collecting existing human liver cells (gleaned from surgical waste, biopsy leftovers, donated livers that aren't suitable for transplants) or creating them from stem cells. Think of these cells as the ink in an ordinary desktop printer.
Then, they load the cells into a machine that deposits them, one by one, into a honeycomb formation about half a millimeter thick. Once the cells mature, they form tissue that functions like the liver in your body. Organovo expects drug testing in this three-dimensional tissues to be much more accurate than the current two-dimensional cell cultures.
This marks the first time Organovo has taken on the liver, a much more complicated target than others it's tackled so far, such as blood vessels. The company plans to begin selling the 3-D-printed liver tissue to drug researchers as early as next year.
Presnell admits that scaling up Organovo's printed liver tissue into something that could be transplanted into a human body will be a formidable challenge. But not an insurmountable one.
She said, "I'm not saying I'm going to give you an entire liver in a box, but I do believe we will see implantable liver tissue in my lifetime."
