Physics Colloquium - Fall 2009 - Edward Brown
Dept of Physics & Astronomy
University of Maine, Orono, Maine
Presents
Edward Brown
Assistant Professor, Dept. of Biomedical Engineering
University of Rochester
Studying the tumor extracellular matrix with nonlinear microscopy
The tumor extracellular matrix is a complex material that influences tumor growth, tumor cell motility, and the availability of nutrients and therapeutic reagents. We are exploring this material with two complementary optical tools: second harmonic generation (SHG) and multiphoton fluorescence recovery after photobleaching (MPFRAP). In our SHG work we are utilizing the polarization and scattering properties of SHG to understand the structure and organization of the tumor extracellular matrix. This organization influences the process of tumor metastasis, and using SHG we are beginning to understand the cells and signals responsible for matrix organization, with the goal of disrupting matrix organization and hence inhibiting metastasis. In our MPFRAP work we are modifying the MPFRAP technique to quantify diffusive transport in the presence of significant convective flows, enabling us to explore diffusive transport in physiological compartments that were previously inaccessible. In this talk we will discuss both of these projects.
Figure 1. Left: The ratio of the fit diffusion coefficient to the true diffusion coefficient, as a function of flow velocity. Using our new model, MPFRAP can now probe diffusion in the presence of flow over flow speeds an order of magnitude higher than previously possible. Right: An image of the ratio of forwards- to backwards-scattered second harmonic signal from a tumor section. The forwards-to backwards-scattering ratio provides quantitative insight into the fibrillar substructure of collagen in tumors.
Friday, October 2, 2009
3:10 p.m.
137 Bennett Hall
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