**Speaker:**Julie A. Stenken, Department of Chemistry and Biochemistry, University of Arkansas.

**Date:**Wednesday, March 13th, 2019, 5:15PM-6:15PM

**Location:**SCEN 204

**Title: **Mathematical modeling for Microdialysis Sampling – From FORTRAN to COMSOL.

**Abstract:** Microdialysis sampling is a technique that uses a hollow-fiber semipermeable membrane (o.d. ~ 200-600 microns) to sample fluid directly from complex matrices. The vast majority of uses for microdialysis sampling has been in biomedical research to collect solutes from mammalian tissues. While understanding the device from a conceptual point of view, i.e., it serves as an artificial capillary in the tissue space is straightforward, the mathematical descriptions for the solute mass transport and ultimately the amount of material recovered into the microdialysis device is far more complex. The combination of different mass transport regions along with the fluid flow through the inner lumen of the microdialysis sampling device sets up a quite complex series of descriptive equations and boundary conditions. The complexity involved with modeling solute mass transport through tissue occurs because the various diffusion and kinetic processes affecting transport are heterogeneous, and oftentimes these parameters (e.g., rate constants or localized density) are unknown. This talk will describe the application of different mathematical models and descriptions for microdialysis sampling used by the speaker over the last 25 years. These examples will include early analytical/steady-state methods to assess diffusivity through new dialysis membranes, to FORTRAN modeling of localized drug metabolism to our current interests in creating and assessing unique fluidic devices to improve sampling using COMSOL.

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