Date of Award

5-2012

Level of Access Assigned by Author

Campus-Only Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Interdisciplinary Program

Advisor

Michael Mason

Second Committee Member

David Neivandt

Third Committee Member

Sharon Ashworth

Abstract

Nanotechnology is an emerging field that holds the potential to advance many areas of industry and medicine due to unique properties of materials at the nanoscale. One particular area of that could be greatly improved is that of medical imaging, specifically X-ray Computed Tomography (CT). Current CT vascular contrast agents are based upon iodine which is rapidly cleared by the renal system and induces nephropathy in many patients. Gold has a higher X-ray attenuation coefficient than iodine, and the surface properties of gold allow for facile surface modification improving stability and biocompatibility. The purpose of this study was to evaluate the potential of gold nanoparticles as an X-ray contrast agent in-vitro and in-vivo, and compare their effectiveness to current contrast agents. Specifically, the relative contrast (or equivalent contrast at a reduced dosage), and the change in signal due to clearance over time were compared. Experiments included an analysis of gold nanoparticle samples by CT both in Eppendorf tubes and in live mice. Mice were injected with dosages of three different sizes of gold nanoparticle solutions at a concentration of 16 mg gold/200|aL water. The mice were then evaluated by CT immediately after injection, 6 hours after injection and 24 hours after injection. These live animal experiments were performed at Memorial Sloan-Kettering Cancer Center in New York City. As a control, several mice were analyzed following injection with Fenestra VC, a standard iodinated vascular CT contrast agent. Gold nanoparticles were found to generate greater contrast when compared to Fenestra VC both in-vitro and in-vivo. Furthermore, this contrast was found to be longer lasting than that generated by Fenestra VC. Gold nanoparticles enabled the visualization of the abdominal aorta in all specimens beyond the 24 hour time point. Though these results were positive, more work is required before gold nanoparticles are a viable contrast agent for use in humans.

Comments

Interdisciplinary in Bioinorganic Materials

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