Probing Lipid-Protein Interactions in Biological Self-Assembly
Prof. Prajnaparamita Dhar, Department of Chemical & Petroleum Engineering
University of Kansas
Project dates: 2012-2015
Mentor: Stevin Gehrke
The optimal cholesterol content in replacement surfactants is currently under debate, primarily because of a lack of understanding of the role of cholesterol in the mechanical and morphological properties of LS monolayers. These mechanical properties, in turn, regulate the surface tension lowering and adsorption properties of the surfactant. The primary goal of Dr. Dhar’s research is to determine, for the first time, the physiologically optimal surface viscosity of the lung surfactant using an active microrheology technique unique to our lab.
She hypothesizes that there exists an optimal surface viscosity in an effective lung surfactant that provides both rapid adsorption to the air-water interface and ultra-low surface tensions. Professor Dhar’s goal is to determine how best to achieve this optimum by controlling the cholesterol fraction of a synthetic replacement lung surfactant. Three orders of magnitude increased sensitivity can be achieved with her microrheology technique as compared to macroscopic rheometers. This allows precise monitoring of changes in the molecular organization of the lung surfactant film in the presence of cholesterol and enables accurate measurements of surface viscosity of surfactant films.
Ultimately, determining the optimal cholesterol concentration will enable a better design of synthetic surfactants to treat Neonatal Respiratory Distress Syndrome (NRDS) and may give insights into the causes of surfactant inactivation in Adult Respiratory Distress Syndrome (ARDS).