2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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TechConnect Summit
Clean Technology 2008

Concentration gradient generation for mammalian cell culture using a novel microfluidic device

A. Shamloo, S.C. Heilshorn
Stanford University, US

Keywords:
microfluidics, concentration gradient, chemotaxis, endothelail cells

Abstract:
A novel microfluidic device was designed in order to generate stable, quantifiable concentration gradients of biomolecules in a cell culture chamber while minimizing the fluid shear stress experienced by the cells. This device is expected to have wide applicability in the study of shear-sensitive cell types such as endothelial cells, non-adherent cell types, and cells cultured in three-dimensional matrices. As a proof of concept, the migration of human umbilical vein endothelial cells (HUVEC) in response to quantified gradients of vascular endothelial growth factor (VEGF) was examined. Finite element simulation and experimental results for concentration distribution inside the cell culture chamber verified the stability of the gradient over multiple hours. HUVEC were observed to migrate towards higher VEGF concentrations across the entire range of concentrations studied (18-32 ng/mL, gradient=14 ng/mL/mm). Furthermore, enhanced numbers of protrusions were observed along the leading edge of the migrating HUVEC for all VEGF concentrations, resulting in an asymmetric distribution of filopodia. These results suggest that the slope of the VEGF concentration gradient, rather than the absolute VEGF concentration, may be the dominant force in regulating HUVEC polarization and subsequent directed migration.


Nanotech 2008 Conference Program Abstract