The Ohio State University

Full Title:  "Multi-scale Mechanics and the Mechanobiology of Respiratory Disorders: The role of Engineering Analysis in Biomedicine"

Abstract:

Recently, it has become increasingly clear that biological cells and tissues are exquisitely sensitive to both internal and external mechanical forces and that these mechanical forces can significantly alter biochemical signaling and cell behavior. For example, the respiratory system contains a complex network of collapsible airways which are constantly exposed to dynamic and complex mechanical forces. These collapsible airways include the Eustachian tube (ET) as well as small pulmonary airways in the deep lung. The inability to open these airways and the cellular damage that occurs during airway inflation leads to several costly respiratory disorders including Otitis Media and Acute Lung Injury. The goal of our laboratory is to understand how forces at multiple scales, including the molecular, cellular and tissue levels, contribute to the pathophysiology of these disorders and to use this information to develop novel surgical and/or pharmaceutical therapies.

In this talk, I will describe two ongoing NIH and NSF funded research projects which are investigating the biomechanical mechanisms of (1) ET dysfunction and (2) Cellular injury in the deep lung. First, I will briefly describe the development of multi-scale computational models of ET function which account for complex tissue anatomies, viscoelastic tissue deformation, fluid-structure interactions and molecular adhesion dynamics. Correlation of these models with in-vivo human subject data has lead to a better understanding of the biophysical mechanisms responsible for ET dysfunction and is being used to develop patient specific therapies. For the second part of the talk, I will describe the development of an in-vitro microfluidic cell-culture system which mimics the reopening of injured airways during mechanical ventilation. This system involves the flow of microbubbles over a monolayer of deformable epithelial cells. Experimental results related to the effect of surface tension dynamics, cellular morphology, cell mechanics and cytoskeletal structure on cell necrosis and detachment will be presented. I will specifically describe how we are using computational mechanics to analyze and explain several counter-intuitive experimental results. Our combined computational-experimental approach is leading to a better understanding of which cell-based therapies may be most effective in preventing lung injury. Finally, I will highlight the important role of mechano-transduction (i.e. the conversion of mechanical signals into biological functions) in acute lung injury.

Bio:

Dr. Ghadiali is currently an Associate Professor in the Biomedical Engineering department and the Department of Internal Medicine, Division of Pulmonary & Critical Care at OSU. He received his B.S. in Chemical Engineering from Cornell University (1994) and his M.S. (1998) and Ph.D. (2000) in Biomedical Engineering from Tulane University. Prior to joining OSU in Sept 2008, he was the Frank Hook Assistant Professor of Bioengineering at Lehigh University and did his post-doctoral work at the University of Pittsburgh. Dr. Ghadiali has won numerous honors including the Parker B. Francis Fellowship in Pulmonary Research and a New Investigator award from the U.S. National Committee on Biomechanics. He currently holds an NSF Career grant as well as an RO1 grant from the NIH. Dr. Ghadiali has authored several publications in leading Biomedical Engineering and Physiology journals.

The seminar will be held in E001 Scott Laboratory.