Research of Deen Group


William Deen closed his lab in 2012 upon partial retirement, and is no longer accepting new research students or fellows. The common theme of his group's research had been the application of engineering principles to biological materials or systems. Most problems worked on were motivated by a desire to understand normal or pathophysiological processes in the body, and their implications for the prevention, diagnosis, or treatment of human disease. Much of the work entailed collaboration with physicians, physiologists, and other biological scientists.

One major focus was the fundamentals of water and macromolecule transport in liquid-filled spaces of molecular dimensions. This is important for understanding mass transfer in body tissues, as well as for designing synthetic membranes or other separation devices. A key objective was to develop models to predict transport hindrances in porous or fibrous materials, based on the size, shape, and electrical charge of the permeating molecule and the nanostructural properties of the material. The theoretical models were tested using membranes or gels of well-defined structure. They were used also to interpret experiments that probe the permeability properties of kidney capillaries in health and disease. Progress was made in relating the ultrastructure of those capillaries to their transport characteristics, through detailed analyses of convection and diffusion at the cellular and subcellular levels.

Another major interest was the transport and reaction of nitric oxide (NO) and its derivatives in biological systems. It is well established that NO is routinely synthesized throughout the body and that it is a key intercellular messenger molecule (e.g., in the regulation of blood pressure). Transient increases in NO synthesis are important also in the response of the immune system to infection, in that the toxicity of NO helps to kill invading microorganisms. However, sustained high levels of NO synthesis (as may occur with chronic infection or inflammation) carries with it the risk of collateral damage to host tissues, including DNA or protein modifications that may lead to cancer. To provide insight into the biological effects of NO and of the various reactive NOx species derived from NO, we studied reaction kinetics and diffusion in aqueous solutions and cell cultures. Using such data, we developed computational models to predict the chemical consequences of cellular NO synthesis in vivo or in vitro.

View chronological list of research publications.

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