Analytical Chemistry Commons^™

Establishing Pteridine Metabolism In A Breast Cancer Cell Model And Quantification Of Silver Nanoparticle Interactions With Yeast Cells Using Mass Spectrometry, Lindsey Katherine Rasmussen

Doctoral Dissertations

"Recent advances in analytical methods have furthered the quantitative insights that can be gleaned from cellular analyses, with applications in cancer and nanoparticle research. In the first part of the research presented, a recently developed HPLC-MS/MS method was advanced to elucidate pteridine metabolism in an isogenic progressive MCF10A breast cancer cell model. The folate-derived pteridine pathway in breast cells was established by individually dosing cell cultures with folic acid and 15 pteridines. Eight potential pteridine biomarkers in breast cancer cells were identified including pterin and isoxanthopterin, which yielded the first in vitro evidence for the cellular metabolisms behind previously reported …

High Throughput Analysis To Study Emerging Pollutants And Nanoparticle Fate In Biological Systems, Xiaolong He

Doctoral Dissertations

”The increasing applications of emerging and fugitive contaminants (EFCs) and engineered nanoparticles (ENPs) attract significant research interest for their potential risks to human health and the environment. In order to assess the health risks of these emerging contaminants, rapid and reliable analytical methods to measure the concentrations and fates of these contaminants are imperative. This dissertation focuses on the developments of advanced analytical methods and their applications to study those emerging contaminants in crop plant and simulated gastric fluid (SGF). Three types of mass spectrometry based methodologies have been developed, one is freeze-thaw/centrifugation extraction followed by high performance liquid chromatography …

Tools To Evaluate Nanodiamond-Mediated Delivery Of Tiopronin For Cataract Prevention, Justin Beltz

Doctoral Dissertations

”There is a growing demand for non-surgical means of cataract treatment. This dissertation presents three bodies of work that reflect the early-stage development of eye drop formulations aimed at delaying cataract progression. These formulations consist of the antioxidant 2-mercaptopropionylglycine (MPG) loaded onto nanodiamond particles.

Cataractogenesis is linked to oxidative damage to lens proteins. To investigate the potential of MPG for protection against oxidative damage, A549 cells were incubated in 0.6 mM tert-butylhydroperoxide (tBHP). Cells exposed to tBHP without MPG exhibited elevated levels of reactive oxygen species, which led to the depletion of the vital antioxidant glutathione and, ultimately, apoptosis. Co-administration …

Design, Synthesis, Characterization And Anti-Cancer Effects Evaluation Of Interchain Cysteine Linked Antibody Drug Conjugates, Ke Li

Doctoral Dissertations

"Antibody drug conjugates (ADCs) are emerging therapeutic products specially designed for the treatment of cancers. Potent cytotoxic agents are linked to antibodies via linkers. Antibody drug conjugates, which take advantage of both antibodies and cytotoxic agents, showed high selectivity towards cancer cells. Cytotoxic agents are delivered to the cancer cells selectively and kill them from inside while leaving low or non-toxicity towards normal cells. Antibody drug conjugates are actually heterogeneous mixtures. The major heterogeneities mainly lie in the drug to antibody ratio (DAR) and drug linking positions, both of which potentially affect the therapeutic index of ADCs. In this research, …

Part I: Design, Synthesis, And Studies Of Novel Age-Inhibitors And Age-Breakers; Part Ii: Novel Synthetic Methods For Organofluorine Compound, Jatin Mehta

Doctoral Dissertations

"Novel small molecule inhibitors and breakers of advanced glycation end-products (AGEs) have been synthesized and their in vitro inhibitory activities have been studied by ¹³C NMR, fluorescence, and UV-visible spectroscopy. We have demonstrated that these AGE-inhibitors and AGE-breakers were found to be more effective in their sequestration of AGE intermediates, such as dehydroascorbate (DHA) than the state-of-the art phenacylthiazolium bromide (PTB)-based AGE-inhibitors and AGE-breakers. Citric acid and other polyphenolic antioxidants have substantial AGE inhibitory effects in the D-glucose/leucine or benzylamine Maillard reaction model systems, and thus they are suitable as dietary additives for ameliorating AGE-induced complications.

Organofluorine compounds have …

Biomarker Discovery Using Urinary Metabolomics For Noninvasive Early Cancer Detection, Casey Franklin Burton

Doctoral Dissertations

"The development of new screening methods for the early detection of cancer remains one of the foremost challenges facing modern cancer research. The emergence of new analytical technologies and their application to 'omics'-based approaches has provided researchers with powerful new tools for molecular biomarker discovery that may benefit early screening of cancer. This dissertation outlines several key advances made toward the application of urinary metabolomics to cancer biomarker discovery. The term urinary metabolomics here refers to the investigation of small metabolites in urine as potential disease biomarkers. The advantage of using this approach lies in its noninvasive sampling characteristics and …

Drinking Water Disinfection By-Products Detection, Formation And The Precursors Removal Study, Runmiao Xue

Doctoral Dissertations

"Haloacetic acids (HAAs) and trihalomethanes (THMs) are two groups of commonly found disinfection by-products (DBPs). Iodinated THMs and HAAs were observed after disinfection of water containing high level of iodide and are proved to be more toxic than their corresponding chlorinated and brominated species. In the presented dissertation, a novel rapid and sensitive high performance ion chromatography-tandem mass spectrometry (HPIC-MS/MS) method has been developed for simultaneous analysis of all these HAAs, bromate, bromide, iodide, and iodate, seventeen compounds in total, without any tedious sample preparation. Besides an efficient analytical method for the detection of DBPs, seeking for a green disinfectant …

Rapid Quantification Of Trypsin Inhibitors In Food And Feed Formulations With Electrospray Ionization Mass Spectrometry, Radheshyam Panta

Doctoral Dissertations

"Presence of anti- nutrients deteriorate the nutritional value of animal foods and feed formulations. The important one being trypsin inhibitors. Trypsin inhibitors in food and feed formulations lower the protein supplement and hence the ultimate consequence is the decrease in growth and development of animals. It is therefore, crucial to monitor trypsin inhibitors in animal food and feed formulations. Research work mentioned in this dissertation is based on the development of rapid, more accurate and robust method for determination of trypsin inhibitor in food and feed formulations. The developed method includes extraction of trypsin inhibitor from food and feed formulation …

Single Particle-Inductively Coupled Plasma-Mass Spectrometry Technology Development For Metallic Nanoparticle Characterization In Complex Matrices, Yongbo Dan

Doctoral Dissertations

"As the rapid growing of nanotechnology, the release of engineered nanoparticles (ENPs) into the environment is inevitable. After entering the real environment, ENPs tend to react with different components of the ecosystem (e.g. water, soil, air, plants) and make their characterization difficult. Analyzing ENPs in these complex matrices still remains as a grand challenge. ENPs characterization is normally the first step of risk assessment. Current analytical techniques have shown some limitations in revealing the unique characteristics of ENPs in complex matrices and reliable analytical techniques are in urgent need. Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) is an emerging …