Artificial cells capable of powering medical implants designed
10 Oct 2008, 1733 Hrs

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Washington, Oct 10 Yale University researchers have designed a blueprint for artificial cells that are more powerful and efficient than the natural cells they mimic - and may soon be used for powering of tiny medical implants.

The scientists began with the question of whether an artificial version of the electrocyte - the energy-generating cells in electric eels - could be designed as a potential power source. "The electric eel is very efficient at generating electricity. It can generate more electricity than a lot of electrical devices," said Jian Xu, a postdoctoral associate in Yale's Department of Chemical Engineering.

It was Xu, who had drawn the first blueprint detailing how the electrocyte's different ion channels work together to produce the fish's electricity.

It was when Xu was a graduate student under former Yale assistant professor of mechanical engineering David LaVan, now at the National Institute of Standards and Technology.

"We're still trying to understand how the mechanisms in these cells work. But we asked ourselves: 'Do we know enough to sit down and start thinking about how to build these things?' Nobody had really done that before," said LaVan.

Based on the new blueprint, the researchers went on to design an artificial cell that could replicate the electrocyte's energy production.

"We wanted to see if nature had already optimized the power output and energy conversion efficiency of this cell. And we found that an artificial cell could actually outperform a natural cell, which was a very surprising result," said Xu.

The new artificial cell had the capability to generate 28 percent more electricity than the eel's own electrocyte, with 31 percent more efficiency in converting the cell's chemical energy - derived from the eel's food - into electricity.

Though eels use thousands of electrocytes to produce charges of up to 600 volts, LaVan and Xu have shown that it would be possible to create a smaller "bio-battery" using several dozen artificial cells.

The tiny bio-batteries would only need to be about one fourth-inch thick to produce the small voltages needed to power tiny electrical devices such as retinal implants or other prostheses.

Although the engineers came up with a design, it will still be some time before the artificial cells are actually built.

On reason may be that they still need a power source before they could start producing electricity. LaVan speculates the cells could be powered in a way similar to their natural counterparts.

He said that it's possible that bacteria could be employed to recycle ATP - responsible for transferring energy within the cell - using glucose, a common source of chemical energy derived from food.

With an energy source in place, the artificial cells could one day power medical implants and would provide a big advantage over battery-operated devices.

"If it breaks, there are no toxins released into your system. It would be just like any other cell in your body," said Xu. (ANI)