GUY RAZ, host:
We're back with ALL THINGS CONSIDERED from NPR News. I'm Guy Raz.
(Soundbite of printer)
RAZ: Your typical ink-jet printer can produce a lot of things, from documents to decent photos, but a scientist from the University of Missouri thought the mechanism behind them could actually do something a lot more complicated.
Gabor Forgacs thinks they could print our organs, as in human organs, and he's built a high-tech printer to do just that. Here's how it works.
Dr. GABOR FORGACS (Scientist, University of Missouri): You scoop out cells from the patient.
RAZ: So if you want a new heart, some cardiac cells, if you want a new stomach, some stomach cells, and so on. And he takes this cluster of cells.
Dr. FORGACS: That may contain anything between 10 to 30,000 cells.
RAZ: And he mixes it into a liquid, something Gabor Forgacs calls bio-ink, and just like in the printer connected to your computer, this bio-ink shoots out of a cartridge. And it's printed, dot by dot, onto a gelatin-like sheet of paper, or what he calls bio-paper.
Dr. FORGACS: It is a material that mimics what we have in our body between the organs, that surrounds the organs. It's called the extracellular matrix. Cells love it.
RAZ: And when placed together on the bio-paper, the bio-ink, those cell clusters, starts to fuse and form shapes, but at this point, the printout is still two-dimensional. So another sheet of bio-paper is layered right on top with another cluster of bio-ink.
The principle is a little like building a skyscraper. You start with the bottom level, then build up.
Dr. FORGACS: Then imagine that comes the second story, and then comes the third story.
RAZ: And on and on until you have something that starts to look like an organ. Forgacs' printer is connected to a computer that then directs how those layers should be shaped, a predesigned scheme a little like paint-by-numbers.
Dr. FORGACS: And that scheme you can get by taking an X-ray or a CT image of the organ, and you try to repeat the outline of the organ. Of course, it's very complicated, but we have now the precision to place the cells according to this scheme and end up with a three-dimensional object.
RAZ: The layers of bio-paper between the cell clusters eventually melt away as the cells start to fuse.
Dr. FORGACS: They fuse both in the plane, so a circle will turn into a little doughnut-shaped object, and they also fuse in the third dimension. So imagine that if you put circular arrangements on top of each other, the stories are like circles, then eventually they fuse and you get a cylinder.
RAZ: And those cylinders are what Dr. Forgacs is on the verge of perfecting right now. He and his team are close to printing out human blood vessels.
Hearts and livers are still a ways away. The first step is to implant these printed blood vessels inside a human body. But how would those printed organs know how to function?
Dr. FORGACS: When we are in embryo, you can ask the same question: how does the embryo know how to form those complicated organs? These are the product of evolutions of many, many millions of years. They know what to do.
RAZ: Now, whether Gabor Forgacs' science can mimic evolution is still a question. The 3-D bio-printer is a long way from showing up at your local hospital, but he thinks human testing can actually begin fairly soon.
Dr. FORGACS: In the next five years there will be a great breakthrough.
RAZ: In the meantime, Forgacs and his team at the University of Missouri are experimenting on rats. They've already implanted some with nerve grafts created with the bio-printer.