The top image shows a patch of epithelial cells. The white lines in the middle image mark the electric current flowing from positive to negative over the cells. The bottom image shows how the cells track the electric field, with blue indicating leftward migration and red signaling rightward movement. (Images by Daniel Cohen)
Creating artificial tissues can be done in a variety of ways, including 3D printing and molding sheets of cells into different shapes. These methods can be difficult to control when trying to get large numbers of cells to their right locations. Now researchers from Berkeley and Stanford have reported in Nature Materials on a new method of using electricity to herd whole groups of cells to their final location.
The team applied a DC current of five volts per centimeter through epithelial cells, perhaps the most common type in our bodies, which made them crawl like a microscopic drove of cattle in the electric current field’s direction. The team was able to make the cells turn left and right, u-turn, and split into groups that go off in different directions.
Besides using this technology to produce artificial tissue constructs, the researchers are looking into whether the same approach can help guide the healing of wounds using smart electronic dressings.
From the announcement:
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 behaviors 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 behavior of sheep, we might be able to similarly herd biological cells for tissue engineering.”
Galvanotaxis – the use of electricity to direct cell movement – had been previously demonstrated for individual cells, but how it influences the collective motion of cells was still unclear.
“The ability to govern the movement of a mass of cells has great utility as a scientific tool in tissue engineering,” said study senior author Michel Maharbiz, UC Berkeley associate professor of electrical engineering and computer sciences. “Instead of manipulating one cell at a time, we could develop a few simple design rules that would provide a global cue to control a collection of cells.”
Study in Nature Materials: Galvanotactic control of collective cell migration in epithelial monolayers…
UC Berkeley: Scientists ‘herd’ cells in new approach to tissue engineering…