Ph.D., Chemical Engineering
B.S., Chemical Engineering and Biomedical Engineering
Accoustic Fields in Bioprocessing, Mathematical Modeling of Metabolism
Acoustic Fields in Bioprocessing
The small size and fragile nature of the mammalian cells that are used to produce pharmaceuticals and tissue for organ replacement result in inherent processing difficulties. Specifically, mass transport to and from the cells may be deficient, especially in bioreactors with high cell concentrations. Excessive agitation can damage the cells, and hydrodynamic entrainment may result in the loss of viable cells from bioreactors in perfusion mode. We are working on several novel designs for the purpose of achieving high cell concentrations and high productivity using applications of acoustic fields. This work is in conjunction with Dr. Donald Feke at CWRU. Our team has demonstrated the effectiveness of a method to separate different populations of cells in suspension according to size and acoustic properties. The fractionation of the cells was accomplished by subjecting the cells to synchronized ultrasonic standing waves and laminar flow fields propagating in the orthogonal direction. It was found that the acoustic method is fast, efficient and can be operated continuously with a high degree of selectivity and yield with low power consumption. Another method for the collection and retention of mammalian cells within a highly porous polyester mesh having millimeter-sized pores, was studied. Cell retention occurs via energizing the mesh with a low intensity, resonant acoustic field. The resulting acoustic field induces the interaction of the cells with elements of the mesh or with each other, and effectively prevents the entrainment of cells in the effluent stream. In addition, the acoustic field was shown to produce a negligible effect on cell viability.
Mathematical Modeling of Metabolism
The Center for Modeling Integrated Metabolic Systems (MIMS) consists of an inter-disciplinary initiative among scientists from Case Western Reserve University and Cleveland State University focusing on complex biomedical systems. Our sub-group is developing a comprehensive mathematical model of metabolism and transport in the human liver. We collaborate with researchers at CWRU who gather metabolic data from both perfused livers and from intact organisms. The data are used to develop reaction and transport kinetics and to validate the model. The model will provide a tool for understanding the regulation of metabolism in the healthy liver under a variety of stresses, and can eventually be used as a framework to analyze the diseased state and proposed remedies.
Research is conducted in the well-equipped Biochemical Engineering Laboratory in the Chemical Engineering Department. The laboratory is equipped with tissue culture facilities, including laminar flow hood, incubators, microscopes, fully-instrumented (2) 1-liter bioreactors, glucose-lactate analyzer, ELISA plate reader, UV/Vis spectrophotometer, autoclave, -70C freezer, centrifuge, and other instrumentation specific to the research projects. Equipment for fermentation (shaker bath, 1-liter fermentor) are available in the separate Fermentation Lab.