Ph.D. Defense in Chemistry
Thursday, May 5 at 12 pm - Byker Auditorium or WEBEX
Nida Shaikh will defend her Ph.D. in Chemistry beginning with a seminar titled "A Thermodynamic and Optical Assessment of Soluble Carbon Particulate Effects on Lipid Film Structure and Organization."
ABSTRACT: The effects of carbonaceous particulate matter on model biological membrane structure, organization, and function are largely unknown. Although the harmful impacts of black carbon are well-documented, researchers lack the chemically-specific, mechanistic information necessary for understanding how black carbon aerosols affect lung surfactant spreading and compression. Surface specific optical spectroscopy methods together with complementary thermodynamic methods are used to measure how carbon nanoparticles, a model for black carbon aerosols that are a component of particulate matter (PM2.5), change average lipid conformation, orientation, thickness, and compressibility in monolayers, and how these changes affect overall membrane organization. Addressing these questions requires a suite of independent, but complementary, experimental techniques including Langmuir trough and surface tension measurements, surface specific nonlinear optical spectroscopy measurements including both second harmonic generation and sum frequency generation, and spectroscopic ellipsometry measurements. Data suggests a cooperative adsorption model as a possible mechanism to explain the interactions between DPPC monolayers and PHFs at biologically-relevant aqueous - air interfaces. The experiments conducted represent a detailed investigation of 1) the mechanism(s) responsible for accumulation of carbon particulates at the aqueous/monolayer/air interface present in the lungs, and 2) how specific thermodynamic behavior and optical properties (i.e. structure, composition, membrane integrity, orientation, thickness, and organization) at the aqueous/monolayer/air interface change with the inclusion of non-biological, carbon particulates. Motivating this work is a need to develop a predictive understanding of black carbon - lung surfactant interactions and how non-biological, nano-sized materials impact membrane structure and function.
- Dr. Robert Walker (Research Advisor)
- Dr. Mary Cloninger (Chemistry and Biochemistry)
- Dr. Erik Grumstrup (Chemistry and Biochemistry)
- Dr. Berk Knighton (Chemistry and Biochemistry)
- Dr. Nick Stadie (Chemistry and Biochemistry)
Manuscripts in Preparation
- Shaikh, N.; Andriolo, J. M.; Skinner, J. L.; Walker, R. A., Carbon Nanoparticle-Induced Organizational Changes in Lipid Monolayers at Water - Air Interfaces. J. Phys. Chem. B. (in review) 2022.
- Shaikh, N.; Bernhard, S. P.; Walker, R. A., Surface Activity and Aggregation Behavior of Polyhydroxylated Fullerenes in Aqueous Solutions. Langmuir (in review) 2022.
- Shaikh, N.; Walker, R. A., Cooperative Adsorption at Liquid Interfaces. Langmuir (in preparation for submission) 2022.
- Shaikh, N.; Andriolo, J. M.; Skinner, J. L.; Walker, R. A., Carbon Nanoparticle-Induced Organizational Changes in Lipid Monolayers at Air - Water Interfaces as a Function of Solution-Phase Ionic Strength. J. Phys. Chem. B. (prepared for submission) 2022.
After MSU: Nida accepted a position as a Licensing Associate with MSU's Technology Transfer Office and TechLink