Chemotaxis in microfluidic devices--a study of flow effects

Area of Science:

• Biophysics
• Cell Biology
• Microfluidics

Background:

• Microfluidic devices are widely used for studying cell chemotaxis.
• These devices provide excellent control over flow and chemical gradients at the cellular level.
• The impact of cell-induced flow perturbations is often overlooked in microfluidic chemotaxis studies.

Purpose of the Study:

• To investigate how three-dimensional cell shapes affect flow fields and chemoattractant gradients in microfluidic devices.
• To analyze the physics governing these interactions in a simplified 2D model.
• To characterize the 3D case and determine optimal flow conditions for chemotaxis experiments.

Main Methods:

• Analysis of underlying physics in a two-dimensional approximation.
• Systematic numerical finite element simulations to model the three-dimensional case.
• Characterization of flow field distortions and chemoattractant concentration distributions.

Main Results:

• Cells attached to microfluidic surfaces significantly perturb the local flow field.
• The concentration distribution across the cell membrane can deviate from ideal gradients due to these perturbations.
• The interplay between flow speed, geometry, and chemoattractant diffusion influences gradient accuracy.

Conclusions:

• Neglecting the 3D nature of cells in microfluidic chemotaxis studies can lead to inaccurate chemoattractant gradients.
• Understanding and quantifying these flow distortions is crucial for designing effective microfluidic experiments.
• Identifying optimal flow conditions can improve the reliability of chemotaxis research using microfluidic devices.