Rice University scientists have determined that skin cells coordinate their motions as they race to cover and ultimately heal wounds. Investigators compared this motion to the way many birds swoop and flock in unison. 

In the past, it was believed that only the cells at the edge of a growing patch of wounded skin were actively moving. Dividing cells were thought to passively fill in the middle of a wound. But Herbert Levine, Ph.D.,  Rice’s Director for the Center for Theoretical Biological Physics, discovered that the process works much more efficiently if highly activated cells in every part of the patch exert force as they pull their neighbors along.

Levine has introduced what he says is “the first iteration of a computer model to analyze the two-dimensional physics of epithelial sheets,” that is, sheets of skin cells. The paper on this research, produced by Levine and colleagues at the University of California at San Diego and in Germany and France, appeared Jan. 25 in the Proceedings of the National Academy of Sciences. Levine and colleagues create computer models of processes seen by experimentalists to flesh out the rules that govern biological systems. 

The team looked to the skies for inspiration. “Birds look around and decide which way all their neighbors are flying,” Levine said. “The idea that they would move as independent birds but also coordinate is where the idea of flocking came from. This way of thinking hadn’t been applied to epithelial tissue motility in wound healing.”