Date of Award

2015

Document Type

Thesis

Department

Chemistry

First Advisor

Andrea Mitchell Goforth

Subjects

Tumors -- Diagnosis, Radiographic contrast media -- Synthesis, Radiographic contrast media -- Testing, Polyethylene glycol, Nanoparticles -- Diagnostic use

DOI

10.15760/honors.162

Abstract

Cancer is responsible for about one fourth of mortalities in the United States daily, however, early diagnosis and treatment raised the five year survival rate since the 1970’s. The usage of X-ray contrast agents (XCAs) has been instrumental in the diagnosis of tumors, but the field still calls for an improved modality in XCAs, such as safe, affordable, lower dosage and targeted XCAs. Useful XCAs must be capable of avoiding the reticuloendothelial system (RES) through an increased circulation half-life time (t1/2), therefore, “evasive” nanoparticle shells have been previously constructed and studied. Researchers have demonstrated an increased t1/2 with the use of molecules such as polyethylene glycol (PEG) and silica. Evasion of RES and an increased t1/2 is primarily attributed to the decreased surface charge and robustness of said shells. Additionally, these properties prevent aggregation and foster further chemical modification for a targeting modality of XCAs. The following work aims to demonstrate a comprehensive synthesis and characterization of bismuth nanoparticles (BiNPs) enveloped by either silica or PEG. A qualitative approach using 1H-NMR and FT-IR strongly suggests said coatings on BiNPs. TEM images suggest a PEG coating was formed while TEM and EDS confirms silica coatings of BiNPs. Preliminary trials of these materials in whole mouse serum advocate silica coated BiNPs are capable of sustaining their integrity in whole serum for at least 3 hours whereas PEG coated BiNPs degrade before 12 hrs. Through an optimized synthesis of either material, conjugation of proteins on surfaces should introduce the targeting component of BiNPs.

Comments

An undergraduate honors thesis submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in University Honors and Chemistry

Persistent Identifier

http://archives.pdx.edu/ds/psu/15619

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