DePaola 9624991 This proposal investigates fundamental issues of the effect of physical stimuli on mammalian cell function and promotes Cellular Engineering education at undergraduate and graduate levels. The main research objective of this proposal is to investigate fundamental aspects of mass transport and fluid mechanics, involved in endothelial cell dysfunction in steady and pulsatile disturbed flow fields. The localization of atherosclerotic lesions in humans coincides with the presence of altered blood flows. We hypothesize that the complex characteristics of these disturbed flows (i.e. variable shear forces, flow separation, vorticity) regulate cellular and biochemical events close to the vessel wall, promoting endothelial cell dysfunction and arterial wall lesions. Endothelial cell cultures will be exposed to well controlled flows, dynamically similar to those occurring in human arterial bifurcations (preferred sites for atherosclerotic lesion development). Visualization experiments and finite element simulations will be used to characterize the flow and to evaluate fluid forces acting on the cell surface. Flow-induced alterations in endothelial function, including cell proliferation, cell migration, monolayer permeability, cytoskeletal fiber reorganization, expression of vascular adhesion molecules, and distribution of leukocyte adhesion to the endothelial monolayer, will be evaluated using in situ inrnunocytochemistry, immunofluorescence, time-lapse video microscopy and epifluorescence microscopy. The physical mechanisms involved in the modulation of endothelial cell function will be identified and mathematical models will be constructed to describe the dynamics of endothelial function and local cell interactions in relation to the flow characteristics. Cellular Engineering has developed into a highly specialized field of research to which engineering students have very little exposure in the classroom and laboratory courses. The main educational objective is to improve the exposure of engineering students interested in biomechanics and biomaterials to Cellular Engineering as a discipline of study. This will be accomplished by course and curriculum development aimed to provide the students with the principles and tools of cellular engineering, in-class discussion of the state of the art, and hands-on research experiences. New courses in Cell Biomechanics will be developed. The senior level Biomechanics and Biomedical Engineering Laboratory courses will be revised to include cellular aspects and state of the art cellular mechanics and transport experiments. A module of "numerical experiments" relevant to cellular engineering will be developed for students to work in a simulation laboratory. A course on experimental cell biomechanics will also be developed and undergraduate research opportunities will be available to provide students with hands-on exposure to research findings. Finally, a journal club will be organized in order to bring together individuals across campus who work in problems relevant to cellular engineering within different fields of expertise . The proposed research activities will contribute to the identification of the physical mechanisms involved in cell pathobiology, in the rearchitecturing of the vessel wall surface, and in the cell injury/dysfunction associated with arterial diseases. Better understanding of the effects of physiological flows on endothelial cell cultures will facilitate the development of hybrid vascular grafts (graft performance appears to be highly dependent on the complex flow environment experienced after implantation). The developed methods and procedures may prove to be useful to the bioprocess industry, which relies on the ability of predicting cell behavior and/or manipulating cell function to manufacture biochemical products. Finally, the evaluation and quantification of cell function/dysfunction in controlled unsteady disturbed flows (a mechanical environment similar to that in which endothelial cells reside in vivo) will advance the state of the art in engineering the cell environment for cell culture studies. The educational component of this project is expected to set up the basis for a comprehensive exposure to Cellular Engineering at undergraduate and graduate levels, It will prepare biomedical engineers to satisfy the increasing need of the modem bioengineering, biotechnology and medical industries for individuals who can successfully apply the principles and methods of engineering to problems in cell and molecular biology. ***
