The team used two different chemicals, one of which attracted the cells and another that repelled them, to demonstrate how they could direct the neutrophils into moving along a path, either toward or away from the microparticles. They could also examine how the cells responded when there were conflicting signals sent by several of the artificial bacteria.
Chemotaxis – the migration of cells based on chemical signals in their environment – plays an important role in a number of biological processes and diseases beyond the immune system. "Understanding how cells move in response to chemical stimuli can help us better understand how a single egg develops into a complex organism or how brain cells grow into a network of neurons in a growing embryo, or how cancer cells spread through the body," Kress said. "This technique could give biologists insight into the ways many different types of cells respond to environmental stimuli in a wide range of situations."
Yale engineers use holographic optical tweezers to manipulate a microparticle, which mimics a bacterium by emitting a bacterial chemical "scent." The neutrophil cell follows the chemical trail to track down the intruder.
(Photo Credit: Eric Dufresne and Holger Kress/Yale University)
Yale engineers created microparticles that mimic bacteria and can be manipulated with holographic optical tweezers. The ones pictured here emit a repulsive chemical ?scent,? which the approaching neutrophil cell tries to avoid as it squeezes past.
(Photo Credit: Eric Dufresne and Holger Kress/Yale University)
Source: Yale University