Chemotaxis of Lipopolysaccharide-Stimulated RAW264.7 Macrophage Cell Line in Microfluidic Channels

Abstract

Chemotaxis, the directed movement of cells in a gradient of chemoattractant, is essential for leukocyte migration under inflammatory conditions, but its accurate analysis is limited because of technical limitation. To investigate chemotactic activities of macrophage cell line, we stimulated RAW264.7 cells with a lipopolysaccharide (LPS) and observed the chemotactic migration of the stimulated RAW264.7 cells in the microfluidic channel. The microfluidic channel platform included the PDMS chamber and channel structure, which is 450 mu m long, 10 mu m wide, and 3 mu m high. The viability, surface phenotype, and production of nitric oxide of LPS-stimulated RAW264.7 cells were analyzed. The chemotactic migration number and speed of LPS-stimulated RAW264.7 cells to chemoattractant CCL5 in the microfluidic channels was evaluated. It was demonstrated that the microfluidic channel structure was feasible for analyzing the chemotactic migration of RAW264.7 macrophage cell line at the single cell level.