Substrate Viscoelasticity Impacts Cells’ Ability to Migrate

A research team at Stanford University has worked to develop and test new types of material that closely imitate the real tissue that surrounds cells. New findings built on this work—published in Nature Materials—upend the textbook view of cell migration and bring better insight into the impact of a material's elastic and viscous properties on cells.

"We found that it makes a big difference if the cancer cells are on a very rigid plastic or if they're on a soft and viscoelastic material, like a Jell-O," said Kolade Adebowale, who is lead author of the paper. "This adds to a lot of recent evidence that the behavior of cancer is not just about the cancer cells—it is also about the environment that the cancer cells interact with."

When the researchers studied the movement of cancer cells on their more tissue-like substrate, the results contradicted existing expectations. "We found that when the substrate is viscoelastic, the cells can migrate quite robustly, even though it is soft," said Ovijit Chaudhuri, who is senior author of the paper. Not only did the study find that cells can migrate on soft, viscoelastic substrates, the researchers also discovered the migration movement is unique. On a stiff, 2D surface like tissue culture plastic, cells adhere to the surface and form a fan-like protrusion. On the viscoelastic materials the team created, the cells didn't spread out so extensively. Instead, they filopodia to drive their movement. Further, their experiments showed the cells use molecular clutch to migrate on the substrates.

"I think what was most surprising was that the material property—viscoelasticity—can have such a dramatic impact on the ability of cells to migrate," said Adebowale. "This challenges the textbook view of how we understand cell migration," said Chaudhuri. "Cells migrate differently on viscoelastic tissue than they do on glass, plastic petri dishes or elastic gels. So, if we want to study cell migration, we need to use viscoelastic substrates." While the study looked at single-cell migration, cancer cells migrate as a group in the body and various stages in development involve the collective movement of cells. Next, the researchers hope to answer the question of how viscoelasticity impacts collective cell migration.