"It's very dramatic," says Denis Wirtz, a Johns Hopkins professor of chemical and biomolecular engineering and co-author of the Nature Methods paper. "The cell stretches way, way out across the chip and then, on command, the tail snaps toward the body of the cell."
Cells survive this programmed-release process and can be tested again and again, the researchers said.
Bridget Wildt, a materials science and engineering doctoral student in Searson's lab, used the device to perform and record movies of the live-cell experiments. Wildt tested cells from the connective tissue of mice during these experiments, but the team plans to try other types of cells in the future.
"In the movies, you can see that the cell doesn't move immediately after the chemical reaction is triggered. We refer to this phenomenon as the induction time of the cell," Wildt says. "After this induction time, the cell then snaps back and contracts. We analyze the rate of the cell's contraction and then compare this information to separate cells released under different conditions using chemicals called inhibitors. From these results we are beginning to understand the processes that regulate cell detachment at the molecular level."
The researchers have speculated that the induction time for cancer cells, as compared to noncancerous cells, would be shorter because cancer cells are more pliable. In the near future, Wildt says, they plan to test this hypothesis in experiments with cancer cells. If this assumption proves correct, it may give them a tool to differentiate between cancerous and noncancerous cells.'/>"/>
|Contact: Mary Spiro|
Johns Hopkins University