Ph.D. Dissertation Defense - ABhat-DPE

Ph.D. (OPTICS) DISSERTATION DEFENSE

Title: Probing the interaction between nanoparticles and lipid vesicles

Presented by Anupama Bhat

11:00am – 12:00, Friday, February 23rd, 2018

OSCAR Building ‐ Seminar Room A103

ABSTRACT:

Ability to grow nanomaterials in different sizes, shapes and functionalities with exceptional control has catalyzed significant advances in nanomedicine, diagnosis and treatment of diseases. The interaction of synthetic nanoparticles (NPs) with cell membranes effectively alters certain physical properties such as fluidity, elasticity, flexibility, and permeability of lipid membranes. Herein, we constructed various vesicle systems using dimyristoyl phosphatidylcholine (DMPC), a zwitterionic phospholipid molecule widely used for model membranes. In some experiments, DMPC vesicles were doped with cholesterol to modulate the membrane integrity. Vesicles were then mixed with colloidal gold or silver nanoparticles (AuNPs/AgNPs) at various sizes and concentrations for further examination and analysis with the fluorescence spectroscopy, the fluorescence microscopy, the atomic force microscopy (AFM), as well as the hyperspectral dark-field microscopy. Our data suggest that AuNPs cause localized stiffening in the membranes whereas fluidization in the long range. AuNPs were found to interact with vesicles in a different way than AgNPs do. What we learned in this work provides better understanding on the mechanisms of AuNP/AgNP and membrane interactions for their respective future applications in nanomedicine and nanotechnology.