Digital Commons Network^™

Electrospinning Piezoelectric Fibers For Biocompatible Devices, Bahareh Azimi, Mario Milazzo, Andrea Lazzeri, Stefano Berrettini, M. Jasim Uddin, Zhao Qin, Markus J. Buehler, Serena Danti

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The field of nanotechnology has been gaining great success due to its potential in developing new generations of nanoscale materials with unprecedented properties and enhanced biological responses. This is particularly exciting using nanofibers, as their mechanical and topographic characteristics can approach those found in naturally occurring biological materials. Electrospinning is a key technique to manufacture ultrafine fibers and fiber meshes with multifunctional features, such as piezoelectricity, to be available on a smaller length scale, thus comparable to subcellular scale, which makes their use increasingly appealing for biomedical applications. These include biocompatible fiber-based devices as smart scaffolds, biosensors, energy harvesters, and …

A Comparative Study On The Monovalent And Divalent Cation Separation Of Polymeric Films And Membranes From Salt Solutions Under Diffusion-Dialysis, Serkan Acar, Hacer Yeşi̇m Cengi̇z, Ayça Ergün, Eymen Konyali, Hüseyi̇n Deli̇göz

Turkish Journal of Chemistry

This study deals with selective separation of mono- and divalent cations from aqueous salt solutions using polymeric films based on polyethylene (PE) and polyamide6 (PA6), and two different commercial nanofiltration (NF) membranes. The diffusion rates (D) of ions (Na$^{+}$ and Ca$^{2+})$, separation factors ($\alpha )$ and ion rejections (R) of the films and NF membranes are examined comparatively as well as their surface morphology and hydrophilicity. It is observed that the diffusion rates of Na$^{+}$are in the range of 0.7-1.8 $\times $ 10$^{-8}$cm$^{2}$.s$^{-1\, }$in the decreasing order of PE $>$ NF90 $>$ NF270 $>$ PA6 while Ca$^{2+\, …

Our Envirome, Spring/Summer 2019, Issue 40

Sustain Magazine

No abstract provided.

Organically Modified Inorganic Nanoparticles For Halochromic Ionophores And Nucleic Acids, William Johnston

Doctoral Dissertations

In this dissertation, four nanoparticle reaction schemes were developed as substrates for halochromic dyes or nucleic acids. The reaction schemes include the use of two substrates: silica nanoparticles and halloysite nanotubes. The protocols can incorporate silica (SiO2) nanoparticles and halloysite aluminosilicate (AlO2SiO2) nanotubes due to the presence of silane groups on the surface of either substrate. The reaction schemes are presented along with detailed protocols which were written to facilitate both reproducibility and to serve as an aid to further study and for easy modification of the protocol to suit a researcher's needs. The data is discussed in the materials …

Spheroid-3d And Monolayer-2d Intestinal Electrochemical Biosensor For Toxicity/Viability Testing: Applications In Drug Screening, Food Safety, And Environmental Pollutant Analysis, Evangelia Flampouri, Shahzad Imar, Kieran O'Connell, Baljit Singh

Articles

The rise of three-dimensional cell culture systems that provide in vivo-like environments for pharmaco-toxicological models has prompted the need for simple and robust viability assays suitable for complex cell architectural structures. This study addresses that challenge with the development of an in vitro enzyme based electrochemical sensor for viability/cytotoxicity assessment of two-dimensional (2D) monolayer and three-dimensional (3D) spheroid culture formats. The biosensor measures the cell viability/toxicity via electrochemical monitoring of the enzymatic activity of nonspecific esterases of viable cells, through the hydrolysis of 1-naphthyl acetate to 1-naphthol. The proposed sensor demonstrated strong correlation (r = 0.979) with viable …

Development, Characterization And Application Of Multi-Detector Flow Injection Systems Based On A Serial Flow Configuration For Simultaneous Multianalyte Determination, Aisha Rashed Al Hameidi Yammahi

Chemistry Theses

Oxidase enzymes have been used successfully in the analysis of several biochemical species such as glucose, lactate, pyruvate, creatine, creatinine, amino acids, cholesterol and sialic acid, by generating - in a single or consecutive reaction -hydrogen peroxide (H₂O₂) as a signal molecule which is commonly detected amperometrically. Some approaches have been also reported to use more than one enzyme in a given system to achieve multi-analyte determination. This study aims to evaluate a novel approach for n-analyte determination based on n-enzyme reactors (each is loaded with one or more oxidase enzyme) as well as n-1 catalase immobilized …

Design And Synthesis Of Circadian Clock Modulators And The Study Of Lov Domain Protein Lkp2 In Arabidosis Thaliana And Brassica Rapa, Aditi Nagar

Chemistry Theses and Dissertations

Circadian rhythms are self-autonomous endogenous clocks synchronized with the rotation of the Earth. With the Earth’s rotation and revolution on its axis, the internal clock undergoes oscillation in the period of ~24 hour and governs day to day activities in most organisms. In humans, it regulates the day to day physiological activities. Today’s modern lifestyle has an impact on health: shift work, jet lag, and irregular eating habits contribute to the misalignment of the endogenous circadian oscillator, thereby, increasing the risk of many metabolic disorders including diabetes, irregular blood pressure, sleep disorders, obesity, depression, and cancer. The primary goal of …

Polysaccharide-Mediated Synthesis Of Melanins From Serotonin And Other 5-Hydroxy Indoles, Koen Vercruysse, Astiney Clark, Noor Alattas, Dylan Brooks, Nafisa Hamza, Margaret Whalen

Chemistry Faculty Research

Aim: As a continuation of our research on the melanin formation from catecholamines, we studied the polysaccharide-mediated oxidation of serotonin and other 5-hydroxy indoles into melanin-like materials. As for the catecholamines, we observed that many polysaccharides promote the oxidation of such compounds, particularly in the presence of Cu²⁺. Methodology: The reactions were monitored using reverse phase-HPLC and size-exclusion chromatography techniques. Melanin-like materials were purified through dialysis and characterized using UV-Vis and Fourier transform IR spectroscopic techniques. Results: One such material, synthesized from chondroitin sulfate type A and serotonin in the presence of Cu²⁺ was found to affect …

The Investigation Of Lactoferrin Nitration: Quantification, Function, And Inhibition, Amani Yahya Alhalwani

Electronic Theses and Dissertations

Lactoferrin (LF) is an iron-binding glycoprotein of molecular mass ca. 80 kDa that is predominantly found in mammalian body fluids. Lactoferrin is a multifunctional protein that has a wide range of properties such as antibacterial, antiviral, anti-inflammatory, and anti-allergic functions. Tyrosine residues in the protein play a part in many lactoferrin functions. Protein tyrosine nitration modification represents an oxidative and nitrosative stress process which can be caused by the exposure of proteins to oxidants from air pollution or disease. Understanding the way nitrated lactoferrin interacts with the biochemical environment of the body is thus important to the broader goal of …

Purification Protocol Development And Analysis Of Binding Properties Of Calmodulin Collagen-Like Protein, Patrick P. Boddie

Honors Theses

Calmodulin is an intensely studied, intracellular, calcium-binding protein that is involved in diverse physiological processes. When bound to calcium, calmodulin undergoes a conformational change that allows it to bind specific target peptides with high affinity, one being the calmodulin binding region of myosin light chain kinase, herein called M13. This high affinity, calcium dependent association has made it a desirable choice for use in a biomaterial for drug delivery for non-steroidal anti- inflammatory drugs (NSAIDs). Two artificial genes have been designed by our lab for use in the proposed biomaterial: calmodulin collagen-like protein (CCLP), a construct composed of two calmodulin …

Reduced Graphene Oxide-Modified Screen-Printed Carbon Electrode For Determination Of Homocysteine Using Catechol, Suchapa Naranaruemol

Chulalongkorn University Theses and Dissertations (Chula ETD)

Homocysteine (Hcy), also known as 2-amino-4-mercaptobutyric acid, is a biomarker that is directly associated with an increased risk of cardiovascular diseases (CVDs). In this work, catechol (CA), which is redox active, had been used as an electron transfer mediator to facilitate the oxidation of Hcy. Typically, CA was first electrochemically immobilized onto the surface of screen-printed carbon electrode; however, the obtained CA-functionalized electrode did not show the electrocatalytic activity towards the detection of Hcy. Therefore, the deter– mination of Hcy was investigated in the solution containing CA using differential pulse voltammetry (DPV) at the reduced graphene oxide-modified screen-printed carbon electrode …

Toward Improving Metalloenzyme Inhibitor Design: A Thermodynamic Study Of Small Molecule Interactions With Copper(Ii), Cobalt(Ii) And Manganese(Ii), Fatimah Aldakheel

College of Science and Health Theses and Dissertations

This work aimed at understanding the interactions of 1) three physiologically relevant transition metal ions copper(II), cobalt(II) and manganese(II) with five tri- or tetra-dentate metal chelators (ligand or L) and 2) the resulting ML complexes with two known metalloenzyme inhibitors, 8-hydroxyquinoline (8-HQ) and acetohydroxamic acid (AHA). The ultimate goal of the work was to identify ligands that can form enzyme active site M²⁺ structural mimetics capable of interacting with metalloenzyme active site inhibitors. The ligands studied were N-(2-(1-methylimidazolyl)methyl)iminodiacetic acid (DA2Im), nitrilotriacetic acid (NTA), tris(2-aminoethyl)amine (TREN), tris(2-pyridylmethyl)amine (TPA), and bis(2-picolyl)amine (BPA) and they were chosen to mimic the coordination environment …

Ligand Modulation Of Sidechain Dynamics In A Wild-Type Human Gpcr, Lindsay D. Clark, Igor Dikiy, Karen Chapman, Karin Ej Rodstrom, James Aramini, Michael V. Levine, George Khelashvili, Soren Gf Rasmussen, Kevin H. Gardner, Daniel M. Rosenbaum

Publications and Research

GPCRs regulate all aspects of human physiology, and biophysical studies have deepened our understanding of GPCR conformational regulation by different ligands. Yet there is no experimental evidence for how sidechain dynamics control allosteric transitions between GPCR conformations. To address this deficit, we generated samples of a wild-type GPCR (A2AR) that are deuterated apart from 1H/13C NMR probes at isoleucine d1 methyl groups, which facilitated 1H/13C methyl TROSY NMR measurements with opposing ligands. Our data indicate that low [Na+] is required to allow large agonist-induced structural changes in A2AR, and that patterns of sidechain dynamics substantially differ between agonist (NECA) and …

On The Structure And Properties Of S-Nitrosated Cysteine Models: A Computational Study, Dmitry Khomyakov

Dissertations (1934 -)

S-Nitrosation of cysteine (Cys) residues, a covalent modification of its S atom by NO group, is a major post-translational modification of proteins. Despite the importance of S-nitrosoproteins in numerous physiological processes, lability of the S-nitrosothiol (-SNO) group hinders the research progress. In this work, computational chemistry methods were applied to S-nitrosated cysteine (CysNO) models to gain a deeper insight into its structure and properties. First, we obtained the most accurate at the moment computational estimation of the molecular structure and properties of CH3SNO model molecule using Feller-Peterson-Dixon (FPD) ab initio protocol. The S–N bond length in cis- CH3SNO is calculated …

Recent Insights Into Nitrite Signaling Processes In Blood, Christine C. Helms, Xiaohua Liu, Daniel B. Kim-Shapiro

Physics Faculty Publications

Nitrite was once thought to be inert in human physiology. However, research over the past few decades has established a link between nitrite and the production of nitric oxide (NO) that is potentiated under hypoxic and acidic conditions. Under this new role nitrite acts as a storage pool for bioavailable NO. The NO so produced is likely to play important roles in decreasing platelet activation, contributing to hypoxic vasodilation and minimizing blood-cell adhesion to endothelial cells. Researchers have proposed multiple mechanisms for nitrite reduction in the blood. However, NO production in blood must somehow overcome rapid scavenging by hemoglobin in …

Exogenous Polyunsaturated Fatty Acid (Pufa) Scavenging Affects Phospholipid Profiles And Virulence Phenotypes In Vibrio Cholerae And Vibrio Parahaemolyticus, Anna Moravec

Honors Theses

AIM: This research had two primary objectives. First, this study sought to determine whether or not exposing Vibrio cholerae and Vibrio parahaemolyticus to polyunsaturated fatty acids (PUFAs) would lead to changes in their respective phospholipid profiles. Secondly, if membrane remodeling occurred, this study sought to determine the impact of membrane modifications on bacterial fitness by evaluating their effect on membrane permeability, biofilm formation, and response to stresses. METHODS: The Bligh and Dyer method was used to extract bacterial lipids, which were subsequently analyzed via thin-layer chromatography (TLC). The effect of fatty acids on bacterial fitness was assessed using stress, biofilm, …

Design, Synthesis And Screening Of Peptidomimetics For Anticancer And Antiviral Drug Candidates, Yi Liang

USF Tampa Graduate Theses and Dissertations

The high demand of novel peptide and peptidomimetics based on the amount of genomic and proteomic data need be matched by synthesis and screening. The design and synthesis of peptide and peptidomimetics are so important because the peptide and protein-protein interaction play a key role in molecule recognition and signaling. The modified peptides have better stability and pharmacokinetic properties which may be guided by rational design and molecular modeling. Now many organic and medicinal chemists have chosen peptide and peptidomimetics as potential drug candidates for many targets.

In this dissertation, research efforts in design and synthesis of cyclic peptides with …

Determination Of Total And D-Amino Acid Content In Mice Brain Tissue By Achiral-Chiral Heart-Cutting Two-Dimensional Liquid Chromatography: Diagnostic And Clinical Relevance And A Comparison Between Non-Perfused And Perfused Tissue, Curran Parpia

Chemistry & Biochemistry Theses - Archive

A heart-cutting two dimensional liquid chromatographic method for the quantification of free amino acid enantiomers from mouse brain tissue is demonstrated. Evidence to support the occurrence of D-amino acids in significant concentrations in physiological samples has spurred studies toward the elucidation of their importance and function. In this work, the level and regional distribution of select amino acids were determined by achiral-chiral LC/LC. Additionally, the effect of tissue perfusion on these levels was investigated. The free amino acid extracts were analyzed as their 9-fluorenylmethyloxycarbonyl derivatives and separated in the reverse phase mode on superficially porous C18. In the second dimension, …

The Interaction Of Glutathione With Platinum, And The Role Of Ph In Altering Ligand Formation Between Platinum And N-Acetylcysteine, Kyle B. Mann

Mahurin Honors College Capstone Experience/Thesis Projects

Cisplatin is an important anti-cancer drug. Structurally, cisplatin is a coordination complex, which means that it has a central metallic atom: platinum. Side interactions prevent cisplatin from effectively treating cancerous cells by reaction with DNA. Cisplatin has a high rate of forming protein adducts, primarily with sulfur containing amino acids. To better understand how cisplatin interacts with sulfur containing amino acids in the body, a platinum compound with an ethylenediamine ligand attached was reacted with N-acetylcysteine and glutathione. The reactions of cysteine with platinum were performed at three pH values: 7.0, 8.5, and 10. NMR spectroscopy was used to examine …

Applications Of Organic Probes For Imaging And Analysis Of Different Cancer Cell Models, Hong Guan

Theses and Dissertations

Novel techniques for better studying cancer cell behavior and progression are extremely important. Our lab is interested in synthesizing specifically designed organic reagents and applying them in the studies of cancers. In this dissertation, we used organic probes to investigate cancer cells in the following topics: determination of amino acid concentration in different types of cancers, tumor toxicity of organic probes towards HER2 positive breast cancer cells, glycoproteins identification in breast cancer cells and development of enzyme activity assay for colon cancer cells.

The first chapter was focused on the determination of cysteine/homocysteine concentrations using turn-on sensors in cancer cells. …

The Detection And Quantitative Analysis Of Endocannabinoids And Endogenous Fatty Acid Amides In Apis Mellifera And Tribolium Castaneum, Perry Robert Mitchell Jr.

USF Tampa Graduate Theses and Dissertations

Endocannabinoids, and the fatty acid amides from which they are a member, have garnered greater scientific interest in the last two decades due to the cannabimimetic properties of these endogenous molecules. The most well-known of these is Anandamide, which has thus far been discovered in several species of animal ranging from C. elegans, fruit flies, to bovine and humans. Because of the importance and increasing impact of these compounds a brief overview is first presented herein, with a major focus on the N-acyldopamines due to the direct impact they potentially pose to human physiology.

Secondly, the detection and …

Synthesis, Characterization, And Evaluation Of Small Molecule-Based Fluorogenic Probes For The Detection Of Cellular Thiols, Rasika Ranatunga Nawimanage

LSU Doctoral Dissertations

Fluorescence methods for disease diagnosis and detection of important analytes are becoming popular route as a technique, as they offer a simple non-invasive approach. Recently, many novel fluorophores and probes have been reported for selectively and sensitively detecting low abundance biological species in disease pathways. Biological thiols, such as glutathione, cysteine, and homocysteine, along with the smallest member hydrogen sulfide, are key thiol analytes in biological environments, and they play a vital role in living systems by maintaining the redox homeostasis of cells. Alteration of their ratios can cause cellular dysfunction and cell death. Furthermore, thiol levels in cells and …

Spectroscopy And Gas-Phase Binding Of Modified Desferrioxamine B Indicator Displacement-Based Sensors, William Scott Jones

Dissertations

A coupling reaction has been used to successfully synthesize two novel probes utilizing coumarin derivatives as fluorophores. The structure, spectroscopy, and thermodynamics of these probes were characterized and studied. These probes, along with a classical probe using a N-methyl-anthranilate fluorophore, are used to take advantage of the ability of siderophores to coordinate Fe³⁺ ions which is coupled with the attractive phosphorescence properties of lanthanide ions. The use of lanthanide metals to create an indicator displacement assays is a novel application of these probes for the detection of Fe³⁺ ions. The use of Tb³⁺ ions as the indicator …

The Roles Of Phosducin-Like Protein 1 And Programmed Cell Death Protein 5 As Molecular Co-Chaperones Of The Cytosolic Chaperonin Complex, Christopher M. Tracy

Theses and Dissertations

A fundamental question in biology is how proteins, which are synthesized by the ribosome as a linear sequence of amino acids, fold into their native functional state. Many proteins require the assistance of molecular chaperones to maneuver through the folding process to protect them from aggregation and to help them reach their native state in the very concentrated protein environment of the cell. This study focuses on the roles of Phosducin-like Protein 1 (PhLP1) and Programmed Cell Death Protein 5 (PDCD5) as molecular co-chaperones of the Cytosolic Chaperonin Complex (CCT).Signaling in retinal photoreceptors is mediated by canonical G protein pathways. …

Selective Anion Sensing By Chiral Macrocyclic Receptors With Multiple Hydrogen-Bonding Sites, Tadashi Ema, Keiichi Okuda, Sagiri Watanabe, Takayuki Yamasaki, Tsuyoshi Minami, Nina A. Esipenko, Pavel Anzenbacher Jr.

Chemistry Faculty Publications

Chiral macrocycles featuring sulfonamide and/or amide groups as anion-binding sites were synthesized. X-ray crystal structures and DFT calculations have shown that they adopt different conformations that may lead to unique binding behavior. Indeed, various anions could be sensed by their colorimetric and/or fluorescence signal output. The chiral macrocycles showed chiral recognition for chiral anions. Furthermore, a multisensor array with two or four chiral receptors discriminated seven phosphate anions (AMP, ADP, ATP, CMP, GMP, Pi, and PPi) with 100% classification accuracy.

Molecular Level Interaction Of Human Fibroblast Growth Factor-1 (Hfgf-1) With Phloridzin, Rammohan Paripelly

Masters Theses & Specialist Projects

Fibroblast growth factors (FGFs) are a family of growth factors which includes twenty three proteins. FGFs work as modulators for various cellular activities like mitosis, differentiation and survival. Among the FGF family, human fibroblast growth factor-1 (hFGF-1), which is also known as acidic fibroblast growth factor, is a potent angiogenic agent, involved in the formation of new blood vessels in various tissues. hFGF-1 is regarded as a prototype of the FGF family. It serves as one of the potential targets in tumor inhibition and obesity due to its involvement in new blood vessel formation in cancerous regions and adipose tissues. …

Development Of Isotags For Nmr Based Metabolite Profiling And Applications, Fariba Tayyari

Open Access Dissertations

NMR spectroscopy is a powerful analytical tool for both qualitative and quantitative metabolite profiling analysis. However, accurate quantitative analysis of biological systems especially using one dimensional NMR has been challenging due to signal overlap. In contrast, the enhanced resolution and sensitivity offered by chemoselective isotope tags have enabled new and enhanced methods for detecting hundreds of quantifiable metabolites in biofluids using NMR spectroscopy or mass spectrometry. In this thesis we show improved sensitivity and resolution of NMR experiments imparted by 15N and 13C isotope tagging which enables the accurate analysis of plasma metabolites. To date, isotope tagging has been used …

Antibiotic Thin Films, Timothy Jennings, Jason Nielsen, Brian Ratcliff, Nina Wallace, Xin Zhong Lai, Paul B. Savage

Journal of Undergraduate Research

Nosocomial infections lead to septicemia, a severe problem in the United States. The Savage group has developed a novel class of antibiotics (CSAs) that can be attached to polymers. Invasive medical equipment can be coated with CSA polymers, forming an antibiotic thin film. Testing has shown the ability of CSA polymers to kill bacteria, which will lead to further testing and future use in the medical field.

Myeloperoxidase, Paraoxonase-1, And Hdl Form A Functional Ternary Complex, Ying Huang, Zhiping Wu, Meliana Riwanto, Shengqiang Gao, Bruce S. Levison, Xiaodong Gu, Xiaoming Fu, Matthew A. Wagner, Christian Besler, Gary Gerstenecker, Renliang Zhang, Xin Min Li, Anthony J. Didonato, Valentin Gogonea, W.H. Wilson Tang, Jonathan D. Smith, Edward F. Plow, Paul L. Fox, Diana M. Shih, Aldons J. Lusis, Edward A. Fisher, Joseph A. Didonato, Ulf Landmesser, Stanley L. Hazen

Chemistry Faculty Publications

Myeloperoxidase (MPO) and paraoxonase 1 (PON1) are high-density lipoprotein–associated (HDL-associated) proteins mechanistically linked to inflammation, oxidant stress, and atherosclerosis. MPO is a source of ROS during inflammation and can oxidize apolipoprotein A1 (APOA1) of HDL, impairing its atheroprotective functions. In contrast, PON1 fosters systemic antioxidant effects and promotes some of the atheroprotective properties attributed to HDL. Here, we demonstrate that MPO, PON1, and HDL bind to one another, forming a ternary complex, wherein PON1 partially inhibits MPO activity, while MPO inactivates PON1. MPO oxidizes PON1 on tyrosine 71 (Tyr71), a modified residue found in human atheroma that is critical for …

Thimerosal Exposure And The Role Of Sulfation Chemistry And Thiol Availability In Autism, Janet K. Kern, Boyd E. Haley, David A. Geier, Lisa K. Sykes, Paul G. King, Mark R. Geier

Chemistry Faculty Publications

Autism spectrum disorder (ASD) is a neurological disorder in which a significant number of the children experience a developmental regression characterized by a loss of previously acquired skills and abilities. Typically reported are losses of verbal, nonverbal, and social abilities. Several recent studies suggest that children diagnosed with an ASD have abnormal sulfation chemistry, limited thiol availability, and decreased glutathione (GSH) reserve capacity, resulting in a compromised oxidation/reduction (redox) and detoxification capacity. Research indicates that the availability of thiols, particularly GSH, can influence the effects of thimerosal (TM) and other mercury (Hg) compounds. TM is an organomercurial compound (49.55% Hg …