"Shaping tissues and organs involves an interplay between genetics and physics. If you can't measure the physical side of it, you can't completely understand the problem," Camps said.
Scientists had previously developed several methods to quantitate how cells push and pull on each other while growing in a dish in the lab. But they had no good way to measure these forces while the cells are building 3D tissues in their natural environment.
Camps decided to invent one. As a doctoral student, he had used oil droplets to measure forces exerted by a network of protein filaments that drive cell movement. Inspired by that work, he decided to try using oil microdroplets as force transducers in living tissues.
Camps and Ingber identified a special oil called a fluorocarbon that remains separate from the cell membrane, like oil does from water, and is safe for cells and tissues. Then they devised a special coating for the droplets so it sticks to cells or to the extracellular matrix. This enabled them to measure how cells push and pull within living tissues.
They also coated droplets with a chemical that made their surface glow when illuminated with a laser, then videotaped under a microscope as cells tugged and pressed on the droplet in 3D. The oil droplets on their own are spherical, but squeezing or stretching them deforms them as if squeezing or stretching a water balloon. By measuring how de
|Contact: Dan Ferber|
Wyss Institute for Biologically Inspired Engineering at Harvard