We've known that flesh wounds create disturbances in the skin's bioelectric field since Emil du Bois-Reymond first placed an injured hand in a galvanometer in 1843. Thanks to a new discovery from a team at the University of Berkeley, we might soon be able to harness those currents to heal ourselves with electricity.
As Bois-Reymond originally discovered in the mid-19th century, damaged human tissue generates a different electrical field than intact flesh on account of the damage to nervous tissue that regulates potassium and sodium ion flow. This difference in electrical current between intact and damaged flesh can actually be measured on a galvanometer.
Bois-Reymond was aware that this electrical field change was occurring, but was never able to exploit that information. The UC Berkeley team has. They have discovered that groups of cells can be "herded" to flow across a surface using electrical fields rather, than physically manipulating them. The results of the US Berkeley research have been recently published in the journal Nature Materials.
When applying an electrical charge of 5V/cm to plates of epithelial cells — the kind that form smooth sheets of epithelium tissue lining your kidneys, cornea, and body cavity — the Berkeley team found that the cells would continually migrate along the current's path. Eventually, the team was able to coerce the cells to migrate at will, turning left and right, moving forward and back, even U-turning. And as you can see from the video above, the cells can even be incited to form the Cal Bears logo.
"This is the first data showing that direct current fields can be used to deliberately guide migration of a sheet of epithelial cells," said study lead author Daniel Cohen, who did this work as a student in the UC Berkeley-UC San Francisco Joint Graduate Program in Bioengineering. "There are many natural systems whose properties and behaviours arise from interactions across large numbers of individual parts — sand dunes, flocks of birds, schools of fish, and even the cells in our tissues. Just as a few sheepdogs exert enormous control over the herding behaviour of sheep, we might be able to similarly herd biological cells for tissue engineering."
This breakthrough could even jump-start the invention of "smart bandages" that not only cover and protect an injury site, but also actively direct the wound's healing by exerting an electrical field and expediting the movement of new skin cells into position. [Nature via Kurzweil]