Growing Livers on Computer Chips
April 4, 2001 -- Computer-chip technology is leading to a new generation of artificial livers -- a concept that could one day lead to new treatments for patients whose own organ is failing.
Researchers at the University of California, San Diego, report the development of a new silicon-chip-based system that keeps normal liver cells alive. These dime-sized "liver bioreactors" contain specially treated silicon chips shaped like muffin tins, with a single, living liver cell in each well of the tin. Tiny holes in the tins let nutrients nourish the cell and let wastes wash away.
It's not just razzle-dazzle science. People with liver failure often die before their livers can repair themselves or be replaced with transplants. An alternative is to try to develop a synthetic organ.
Current prototypes are not yet commercially available, but the models in development borrow some of the science from kidney dialysis machines. Since the liver is far more complex than the kidney, however, artificial livers have to filter blood through cartridges filled with actual liver cells taken from pigs or, in more recent devices, from humans. The problem is that liver cells are very finicky; it's very hard to keep them alive inside these machines or even tell how healthy they are.
"You shove the cells in and hope they function," study co-author Sangeeta N. Bhatia, MD, PhD, tells WebMD. "Now, potentially, we could see how they are doing."
"The goal is to make an artificial bioreactor out of silicon," co-author Michael J. Sailor, PhD, tells WebMD. "If you could keep those cells alive long enough to perform their function for a couple of weeks, it would be a major advance."
In studies reported Tuesday at the annual meeting of the American Chemical Society in San Diego, Bhatia, Sailor, and colleague Boyce E. Collins, PhD, announced their finding that silicon chips can be engineered to create the kind of environments that can happily house living liver cells.
"The idea is that as people understand more and more about the molecular biology of cells, we will be able to replicate the conditions under which cells live in the body," Collins tells WebMD. "We could reproduce whatever it is that helps the cells grow better as a tissue than as a group of disorganized cells."
The current studies demonstrate that this concept might be achieved -- but it has not yet resulted in an actual artificial liver. Still, stacks of these silicon chips could one day be at the heart of such a device.
"I have a feeling this will make a contribution to somebody's artificial liver sometime down the road," Collins says. "The miniaturization of our device is exciting because you can put 300,000 cells onto one tiny chip, and then you could stack the chips to quickly have a large cell population that can do a lot of blood filtering. The year 2005 bio-liver will probably use this technology."