A potato clock
Did you ever make a potato clock as a kid? You know, that science experiment where you jam copper and zinc wires into potatoes and connect them with miniature jumper cables to power a clock?
Did you know that the reaction that makes elementary school potato clocks tick could also fight infection and disease?
In published research, Professor Jeremy Gilbert found that when titanium and magnesium particles are galvanically coupled, like zinc and copper in a potato clock, an electrochemical reaction develops that produces a cell-killing effect. If applied to medical treatments, it may lead to treatment options for all kinds of infections—from superbugs to cancerous tumors.
“What makes the potato clock work is the large voltage difference between the copper and zinc. It causes a current to follow through the potatoes to drive the clock. There’s a voltage difference between the two metals that makes it possible. The bigger the difference, the stronger the reaction. Magnesium and titanium have nearly a two-volt difference. It’s a very strong coupling and it produces a powerful effect,” says Gilbert.
That powerful effect—a reductive electrochemical reaction that generates reactive oxygen intermediates—kills cells in close proximity.
Gilbert, an expert in biological implants like hip replacements, believes that one way these findings could be put to use in infection prevention for titanium implants. Infections that take hold on the surface of implants are notoriously challenging to defeat. They withstand even the most powerful antibiotics. By adding magnesium to the titanium surface of an implant, the implant itself is given the ability to kill bacteria before they are able to harm the patient.
This research also reveals an application for killing cancer cells. Our body normally has mechanisms to stop cells from dividing uncontrollably, but when it fails to do so, cancer develops. The negative voltages that Gilbert and his fellow researchers apply induce cellular apoptosis, or cell death, so it may be a way of killing cancer cells that don’t get the message to die off naturally.
This fundamental breakthrough provides a foundation for scientists to build upon and is a strong example of how science that can be understood for something as simple as a potato clock can be used to blaze a new trail in other areas.
Gilbert says, “It’s a novel idea to use an electrochemical process to adapt implants to control infections or treat other conditions. These findings will be the underpinning for new ideas in healthcare.”
