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

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Clean Technology 2008

A Bridged µLane System for Molecular Diffusivity Measurement and Cell Response Analysis

Q. Kong, M. Vazquez
City College of New York, US

Keywords:
microfluidic device, diffusivity, concentration gradient, chemotaxis

Abstract:
The diffusion of small molecules between cells and tissues is often critical in biological study, as molecular concentration gradients are well-known to regulate homeostasis, assist in wound repair, and direct cancer metastasis. However, precise measurement methods of diffusion coefficients for biological compounds, such as growth factors and hormones, remain under development and investigation. Using the novel techniques of microfabrication, we have developed a microfluidic device of two-layer PDMS, the so-called bridged µlane system, to measure the diffusivity of small molecules and establish measurable concentration gradients of these biomolecules along micron distances. The diffusivity of Dextran was firstly measured within the lane system as a control to facilitate the measurement of the diffusivity of Epidermal Growth Factor (EGF), widely used in cell behavior study. Further, by establishing measurable, non-linear, transient and steady-state molecular concentration gradients within the bridged µlane system, distinct EGF gradients generated via convective diffusion were observed to initiate changes in cell migration, morphology, and proliferation within our system. Cells were found to migrate in different patterns while non-linear EGF gradients within the lane stimulated more cells to move at higher concentration gradient. Further experiments of cell chemotaxis within 3-D extracellular matrixes were performed to study cancer metastasis.


Nanotech 2008 Conference Program Abstract