Doctor of Philosophy (PhD)
Lipids are fundamental to all life forms, a key component of cell walls, and essential to proper respiratory function. They are amphiphilic molecules and readily form bilayers. Dendrimers are designer molecules that can be tailored to provide a variety of endgroup moieties, sizes, and charges. The interaction of liposomes and dendrimers can provide information on how medicine interacts with cells and an array of unique structures can be imagined from their assembly into superstructures. Polypropylenimine tetraamine (DAB-Am) and 1-directional arborol dendrimers have been studied in different molar concentrations with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayers. One-directional arborols are amphiphilic dendrimers with a hydrophilic head group composed of 9 hydroxyl groups and a short alkyl chain for the hydrophobic tail while DAB-Am is a uniform, hydrophilic dendrimer.
Designing, building, and repairing equipment added instrumentation to Louisiana State University’s research infrastructure and provided capabilities to perform experiments without traveling to distant laboratories. Small angle X-ray scattering (SAXS) was installed at the Center for Advanced Microstructures and Devices (CAMD) in 2002 and has begun to produce useful information about the size and structure of molecules. Its versatility and availability makes it a powerful tool for researchers and the user base is growing. The Balzers BAF 400 Freeze Etching equipment, or FF, was reintroduced after about 10 years of inactivity and, if properly maintained, will provide scientists the ability to explore samples in situ for years to come.
These techniques have been used to study dendrimers’ interactions with lipid bilayers. The liposome decreases in size upon the addition of 1 × 10-6 moles per liter of dendrimer or less. As the dendrimer concentration increases, the lipid bilayer increases until it is no longer visible in SAXS spectra. FF-TEM shows the formation of large aggregates at high dendrimer concentration, 5 × 10-6 moles per liter.
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Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.
Dorman, Derek R., "A Study of the Interactions of Lipid Bilayers and Dendrimers Using Small Angle X-Ray Scattering and Freeze Fracture Transmission Electron Microscopy" (2010). LSU Doctoral Dissertations. 2923.