The energy supply that drives sperm could be harnessed to power nanomachines, say medical scientists at Cornell University in New York, US.
Sperm generate their energy partly on-site, modifying the enzymes involved in the breakdown of glucose so that they can attach themselves to a solid structure running the length of the sperm tail. Glycolytic enzymes convert the sugar into adenosine triphosphate (ATP), supplying energy along the bending and flexing tails that enable sperm to swim.
Alex Travis, Chinatsu Mukai and others looked at the early steps in the glycolysis pathway to see if they could reproduce the process on a solid nickel-nitrilotriacetic acid chip.
Replacing the sperm-specific targeting domain of the hexokinase enzyme with a tag that binds to a special gold surface, the researchers found that the enzyme remained functional when tethered. They then tagged the second enzyme in the pathway, and found that this too remained active when tethered. With both attached to the same support, the enzymes act in series, with the product of the first reaction serving as a substrate for the second.
“One of the major limitations in making implantable nanomedical devices practical is providing power to them,” says Travis. “You can load liposomes with ATP to power a biological reaction, but then you lose control over the rate at which the reaction takes place. If you can engineer a device that can generate its own energy, then it can potentially last much longer, and also help regulate the rate at which it performs its task.”
As well powering nanoscale machines, Travis says that the process could be used in a nanoscale pump that releases chemotherapeutics or antibiotics in specific places at specific rates.
Travis and his colleagues have a provisional patent on their discovery, and are looking for commercial partners to take the technology forward.
Figure: The biochemical process known as glycolysis that drives the movement of sperm could be harnessed to power nanomachines, say Cornell University scientists (source: Chinatsu Mukai/Cornell University).
Article first published in Nanomaterials News.