The Waterloo Institute for Nanotechnology (WIN) is pleased to present a Distinguished Lecture by Gerald Fuller, Fletcher Jones II Professor in the Department of Chemical Engineering at Stanford University, California, USA.
In-person in QNC 1501!
Registration is required. Please register early as there is limited in-person seating.
Two Problems in Bio-Rheology and Bio-Fluid Mechanics
Abstract
Mucus that lines the lungs acts as the primary defence against inhaled foreign particles and infectious agents by trapping the invaders and preventing them from penetrating the tissue layer. Effective mucus clearance, and thus removal of the trapped invaders is vital for healthy airway function. The rheological properties of mucus, e.g. viscosity and elasticity, can vary dramatically with diseases such as asthma and cystic fibrosis (CF), where thickened and concentrated mucus builds up and occludes the airway. We present a custom device to measure mucus rheology in situ directly on live cell cultures. We used this instrument to conduct creep compliance measurements of mucus on live cultures from healthy, asthmatic, and CF donors. We examined the change in mucus properties with inflammatory stimulation by cytokine interleukin-13, associated with asthma, and with CF treatment of a combination of elexacaftor, tezacaftor, and ivacaftor (ETI). With these studies, we demonstrate the ability to quantify changes in mucus viscoelasticity with various disease models and drug treatments, giving us unique insight into the mechanisms of pathologic mucus production.
The study on tear film stability explores the impact of electrostatic interactions and hydrogen bonding on tear film stability, a crucial factor for ocular surface health. While mucosal and meibomian layers have been extensively studied, the role of electrolytes in the aqueous phase remains unclear. Dry eye syndrome, characterized by insufficient tear quantity or quality, is associated with hyperosmolality, making electrolyte composition an important factor that might impact tear stability. Using a model buffer solution on a silica glass dome, we simulated physiologically relevant tear film conditions. Sodium chloride alone induced premature dewetting through salt crystal nucleation. In contrast, trace amounts of solutes with hydroxyl groups (sodium phosphate dibasic, potassium phosphate monobasic, and glucose) exhibited intriguing phenomena: quasi-stable films, solutal Marangoni-driven fluid influx increasing film thickness, and viscous fingering due to Saffman-Taylor instability.
Biography
Gerald Fuller is the Fletcher-Jones Professor of Chemical Engineering at Stanford University. He joined Stanford in 1980 having received his Ph.D. from Caltech and his B.Sc. from University of Calgary. His research interests lie in the subjects of interfacial fluid mechanics and rheology with a particular focus on problems in biophysical phenomena, foams, and emulsions. His work has been recognized by receipt of the Bingham Medal of the Society of Rheology, election to the National Academy of Engineering, and Fellowship in the American Academy of Arts and Science. He has been granted honorary doctorates from the Universities of Crete and Leuven. He presently serves as the General Secretary of the International Committee on Rheology.