Author

Nina A. Smith

Date of Award

2019

Degree Type

Thesis

Degree Name

Master of Science in Chemical Engineering

Department

Washkewicz College of Engineering

Subject Headings

Biomedical Engineering, Biomedical Research, Chemical Engineering

Abstract

Magnetophoresis of red blood cells (RBCs) at varying partial pressures of oxygen (pO2) is hypothesized to rejuvenate stored blood to be utilized beyond the FDA regulated 42-day storage time. Magnetophoresis is a particle or cells motion induced by an applied magnetic field in a viscous media. The average magnetophoretic mobility of an oxygenated RBC is -0.126x10-6 mm3-s/kg, and a deoxygenated RBC is 3.66x10-6 mm3-s/kg, presenting magnetophoresis as a resource for RBC rejuvenation in hopes of storing it longer than 42 days. The main objective of this paper was to determine if controlling the pO2 within an RBC suspension, can singly- doubly- triply- or fully deoxygenated RBCs be identified by means of cell tracking velocimetry (CTV). These results agreed with the cooperative binding scheme developed by Hill, especially from ~30-40 to 160 mmHg. From 0 to 30 mmHg, further research must be completed to characterize the binding behavior of oxygen and hemoglobin. The validation of the magnetic energy density gradient value (Sm, currently at 365 T-A/mm2) utilized within CTV, and the exact location for the field of view (FOV, currently set to 4.5 mm from the edge of the magnet assembly) were needed to state particle motion was independent of location within the CTV channel. The FOV location was successfully verified 4.5 mm from the edge of the magnet assembly, however, the Sm value, 880 T-A/mm2, was 140% higher than the original. Spectrophotometry was utilized to validate the oxygenation state of RBCs. Results confirmed spectrophotometry was a reliable model for RBC magnetophoresis. CTV post-processing was tested with glioma progenitor cells. Scatter plots generated for these experiments demonstrated cells with different magnetic mobilities in a sample can be detected. To fully characterize the glioma progenitor cells, more experiments must be completed. Lastly, applying a temperature gradient to the magnetic deposition microscopy (MDM) assembly to enhance the separation of RBCs was explored. Preliminary results determined, introducing a temperature gradient of 40°C was large enough to affect the RBC sedimentation rate in the channel. After, modeling within COMSOL was completed, however, more time and knowledge of COMSOL is needed to generate practical results.

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