Microfluidic platforms for studying cell behavior

Neutrophil chemotaxis and intercellular signaling via diffusible molecules are vital physiological processes in the human body. The two processes play a role in diseases and disorders such as rheumatoid arthritis, tumorigenesis, and sepsis. A better understanding of the two processes will aid in the development of new therapeutics. However, conventional methods used to study chemotaxis and intercellular signaling have limited control over the microenvironment. Control over the microenvironment is required to generate multiple independent gradients and modulate spatial and temporal presentation of signaling molecules, which is needed to study neutrophil chemotaxis and intercellular signaling respectively. Microfluidic platforms have the potential to study these biological processes due to the inherent control over the microenvironment. Here, we used PDMS-based microfluidic platforms to study neutrophil chemotaxis and intercellular signaling. The microfluidic platforms were used to generate stable opposing linear gradients of the intermediary chemoattractants LTB4 and IL-8. In the opposing linear gradients, neutrophils exhibited an oscillatory behavior migrating between the two chemoattractant maxima. Finally, a microfluidic platform to study intercellular signaling via diffusible molecules was developed and validated. The microfluidic platforms developed and used here enable detailed study of important biological phenomena such as neutrophil chemotaxis and intercellular signaling via diffusible molecules