
Imagine a tiny robot or drug-delivery device that could swim through your veins, using blood sugar as its fuel. Such a device could be powered by the same chain of chemical reactions that propel sperm toward an egg, according to researchers at Cornell University.
The researchers are trying to reproduce (pardon the pun) the steps whereby a sperm's whiplike tail generates energy. (Sperm also generate energy using the mitochondria in their midsection.) Running the length of the tail is a fibrous sheath with 10 enzymes attached to it. These enzymes act in series to break down glucose into ATP, the energy source for cells, in a process known as glycolysis.
So far, the Cornell researchers have managed to attach three of the 10 enzymes to a computer chip and confirm that the enzymes still work. If they can attach all 10 enzymes, they'll have a working version of a sperm engine, which could then be attached to nano-devices. The researchers presented their findings at the American Society for Cell Biology's annual meeting today.—Dawn Stover

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