Chemistry Commons^™

Engineering Exosomes To Specifically Target The Mitochondria Of Brain Cells, Xin Yan, Xinqian Chen, Zhiying Shan, Lanrong Bi

Michigan Tech Publications, Part 2

Mitochondrial dysfunction is associated with various health conditions, including cardiovascular and neurodegenerative diseases. Mitochondrial-targeting therapy aims to restore or enhance mitochondrial function to treat or alleviate these conditions. Exosomes, small vesicles that cells secrete, containing a variety of biomolecules, are critical in cell-to-cell communication and have been studied as potential therapeutic agents. Exosome-based therapy has the potential to treat both cardiovascular and neurodegenerative diseases. Combining these two approaches involves using exosomes as carriers to transport mitochondrial-targeting agents to dysfunctional or damaged mitochondria within target cells. This article presents a new technique for engineering brain-derived exosomes that target mitochondria and has …

Engineering Exosomes To Specifically Target The Mitochondria Of Brain Cells, Xin Yan, Xinqian Chen, Zhiying Shan, Lanrong Bi

Michigan Tech Publications, Part 2

Mitochondrial dysfunction is associated with various health conditions, including cardiovascular and neurodegenerative diseases. Mitochondrial-targeting therapy aims to restore or enhance mitochondrial function to treat or alleviate these conditions. Exosomes, small vesicles that cells secrete, containing a variety of biomolecules, are critical in cell-to-cell communication and have been studied as potential therapeutic agents. Exosome-based therapy has the potential to treat both cardiovascular and neurodegenerative diseases. Combining these two approaches involves using exosomes as carriers to transport mitochondrial-targeting agents to dysfunctional or damaged mitochondria within target cells. This article presents a new technique for engineering brain-derived exosomes that target mitochondria and has …

Fluorescent Molecular Rotors As Versatile In Situ Sensors For Protein Quantitation, Kevin Daus, Sorachat Tharamak, Wanchai Pluempanupat, Peter Galie, Maria A Theodoraki, Emmanuel A Theodorakis, Mary Alpaugh

Faculty Scholarship for the College of Science & Mathematics

Accurate protein quantitation is essential for many cellular mechanistic studies. Existing technology relies on extrinsic sample evaluation that requires significant volumes of sample as well as addition of assay-specific reagents and importantly, is a terminal analysis. This study exploits the unique chemical features of a fluorescent molecular rotor that fluctuates between twisted-to-untwisted states, with a subsequent intensity increase in fluorescence depending on environmental conditions (e.g., viscosity). Here we report the development of a rapid, sensitive in situ protein quantitation method using ARCAM-1, a representative fluorescent molecular rotor that can be employed in both non-terminal and terminal assays.

Binding Interactions Of Biologically Relevant Molecules Studied Using Surface-Modified And Nanostructured Surfaces, Palak Sondhi

Dissertations

This research focuses on the field of surface nanobioscience, wherein different nanosurfaces that will be used as working electrodes in the electrochemical cell are manufactured and surface modified to understand the critical binding interactions between biologically significant molecules like proteins, carbohydrates, small drug molecules, and glycoproteins. This research is essential if we are to determine whether a synthetic molecule can serve as a therapeutic candidate or diagnose a disease in its early stages. In order to fully understand the binding interactions, the study begins with defining some of the fundamental concepts, principles, and analytical tools for biosensing.

Afterwards, we addressed …

Synthesis, Characterization, And Photophysical And Fluorescence Sensor Behaviors Of A New Water-Soluble Double-Bridged Naphthalene Diimide Appended Cyclotriphosphazene, Süreyya Oğuz Tümay, Serkan Yeşi̇lot

Turkish Journal of Chemistry

A new water-soluble template of double-bridged naphthalene diimide appended cyclotriphosphazene was prepared, and its photophysical and sensor behaviors were evaluated. The characterization of novel double-bridged naphthalene diimide appended cyclotriphosphazene (6) was carried out by NMR (1 H, 13C, 31P) and mass spectroscopies. The photophysical behaviors of compound 6 were evaluated by UV-Vis absorption and fluorescence spectroscopies in various solvent systems and different concentrations. As an application for usability of the obtained water-soluble template in different applications, the fluorescence sensor property of compound 6 was investigated in the presence of many different competing species (organic acids, saccharides, nitroaromatic compounds, anions, and …

Heterocyclic Molecules With Esipt Emission: Synthetic Approaches, Molecular Diversities, And Application Strategies, Nuretti̇n Mengeş

Turkish Journal of Chemistry

Excited-state intramolecular proton transfer (ESIPT) is one of the most essential emission processes in most circumstances because of its dual emission band in most cases and its high Stokes shifts. These distinguishing properties make ESIPT-based probes more suitable for a variety of applications, including analyte sensors, solid-state sensing mechanisms, optical technologies, and biomarkers for endogenous or exogenous compounds in various settings. As a result, researchers around the world are working on ESIPT emissions and developing different scaffolds for various applications or industry demands. This field of study is rapidly expanding and there is a need for an up-to-date review of …

Research Instrumentation Center (Ric), Ryan Hilger, Purdue University Office Of Research

University Research Core Facility Boilerplate Descriptions

No abstract provided.

Photophysical Properties Of Synthetic Oligomeric Phenylene Ethynylene, Hugh F. Fritz Jr.

Chemistry and Chemical Biology ETDs

Oligomeric Phenylene Ethynylenes (OPEs) are a class of synthetically prepared compounds with the basic structure of phenylene rings connected by triple-bonded carbon atoms, also known as an ethyne link. This structure can be modified by incorporating functional groups onto one or more of the phenylene rings. The addition of functional groups, such as sulfoxide or imidazole, may alter the photophysical properties in detectable ways. The photophysical techniques used in this report include fluorescence, spectroscopy in the ultraviolet and visible light range (UVVIS), and photon-based excitation using a photo chamber.

One attractive function of OPEs is their antimicrobial property. Previously published …

Structural Integrity And Stability Of Dna In Ionic Liquid And Near-Infrared Indolizine Squaraine Dye, Ember Yeji Suh

Honors Theses

Luminol, the most common presumptive test for blood at a crime scene, has multiple issues, such as false positive results with chemical agents, no luminescence due to “active oxygen” cleaning agents on bloodstains, and inability to penetrate textile materials. A combination of indolizine squaraine dye and ionic liquid (IL), or Dye Enhanced Textile Emission for Crime Tracking (DETECT), have shown potential to address these issues. The purpose of this study was to assess the binding mechanism of CG (1:1) and SO₃SQ dye to HSA and how the mechanism can explain the W214 fluorescence quenching effect and to determine …

Tenvr: Matlab-Based Toolbox For Environmental Research, Aleksandar I. Goranov, Rachel L. Sleighter, Dobromir A. Yordanov, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

With the advancements in science and technology, datasets become larger and more multivariate, which warrants the need for programming tools for fast data processing and multivariate statistical analysis. Here, the MATLAB-based Toolbox for Environmental Research "TEnvR" (pronounced "ten-ver") is introduced. This novel toolbox includes 44 open-source codes for automated data analysis from a multitude of techniques, such as ultraviolet-visible, fluorescence, and nuclear magnetic resonance spectroscopies, as well as from ultrahigh resolution mass spectrometry. Provided are codes for processing data (e.g., spectral corrections, formula assignment), visualization of figures, calculation of metrics, multivariate statistics, and automated work-up of large datasets. TEnvR allows …

Structure-Emission Relationship Of Some Coumarin Laser Dyes And Related Molecules: Prediction Of Radiative Energy Dissipation And The Intersystem Crossing Rate Constants, Msa Abdelmottaleb

Turkish Journal of Chemistry

Dye lasers are commonly used in optical investigation because their solutions in organic solvents deliver tunable, coherent emissions. They exhibit intense fluorescence owing to some specific spectroscopic characteristics. One drawback of the laser dyes is that it shows excessive triplet-state losses (TSLs.) The lack of theoretical predictions of fluorescence rates, intersystem crossing (ISC), and phosphorescence in laser dyes prompted us to report on the predicted rates of radiative and nonradiative transitions of some laser dyes. Structural engineering by some substituents influencing the simulated rates of coumarin laser dye derivatives for an efficient operation was investigated. The NH$_{2}$ functional group renders …

Labeling Microplastics With Fluorescent Dyes For Detection, Recovery, And Degradation Experiments, Zhiqiang Gao, Kendall Wontor, James V. Cizdziel

Faculty and Student Publications

Staining microplastics (MPs) for fluorescence detection has been widely applied in MP analyses. However, there is a lack of standardized staining procedures and conditions, with different researchers using different dye concentrations, solvents, incubation times, and staining temperatures. Moreover, with the limited types and morphologies of commercially available MPs, a simple and optimized approach to making fluorescent MPs is needed. In this study, 4 different textile dyes, along with Nile red dye for comparison, are used to stain 17 different polymers under various conditions to optimize the staining procedure. The MPs included both virgin and naturally weathered polymers with different sizes …

Uv- And Visible-Light Photopatterning Of Molecular Gradients Using The Thiol–Yne Click Reaction, Mark Mitmoen, Ofer Kedem

Chemistry Faculty Research and Publications

The rational design of chemical coatings is used to control surface interactions with small molecules, biomolecules, nanoparticles, and liquids as well as optical and other properties. Specifically, micropatterned surface coatings have been used in a wide variety of applications, including biosensing, cell growth assays, multiplexed biomolecule interaction arrays, and responsive surfaces. Here, a maskless photopatterning process is studied, using the photocatalyzed thiol–yne “click” reaction to create both binary and gradient patterns on thiolated surfaces. Nearly defect-free patterns are produced by first coating glass surfaces with mercaptopropylsilatrane, a silanizing agent that forms smoother self-assembled monolayers than the commonly used 3-mercaptopropyltrimethoxysilane. Photopatterning …

Mechanism Of Sila- And Germafluorenes For Biological Applications, Shelby Jarrett

Dissertations

2,7-disubstituted silafluorenes and germafluorenes, originally designed for OLED applications, are a class of fluorescent dyes that have gained recent interest as probes for bioimaging and as biosensors to monitor cellular dynamics and interactions. Desirable biological probes absorb in the visible region, have high extinction coefficients, high quantum yield and excellent photostability. Here, their spectral properties are investigated under aqueous conditions for relevant biological applications. These molecules display intense blue fluorescence in the solid state and in solution, have high extinction coefficients, and exhibit appreciable solubility in aqueous solution. To better understand potential applications, the mechanism of fluorescence was investigated. It …

The Design And Testing Of Fluorescence-Based Sensors For Phosphate And Phosphonate, Sara Hassanzadehroknabadi

Electronic Theses and Dissertations

Inorganic phosphate (Pi) is an essential compound for all living things, as it serves as a component of nucleic acids and ATP, which are required for plant growth and proliferation. However, when excess Pi enters the aquatic environment, it has severe detrimental effects through the induction of harmful algal blooms (HAB), which negatively impact aquatic life, the quality of drinking water as well as recreational activities. It is therefore critical to have fast, sensitive, and inexpensive sensors for Pi that quickly and quantitively measure its concentration in a field setting.

Phosphonates or organophosphorus compounds are phosphoric acids possessing alkyl or …

The Investigation Of Fluorescence And Metal Interaction Properties Of Racemic 7,8,9,10-Tetrahydro-3-Hydroxy-4-(1-Hydroxyethyl)Benzo[C]Chromen-6-One, Hayretti̇n Ozan Gülcan, Kharar Tawfeeq Shukur, Açelya Mavi̇deni̇z, Okan Si̇rkeci̇oğlu, Mustafa Gazi̇

Turkish Journal of Chemistry

The design or investigation of fluorescence probes continues to receive attention with respect to the diverse applications of spectrofluorometry. Depending on the highly sensitive character, fluorescence spectroscopy-based methodologies have been widely used in recent years in different sciences, including analytical, environmental, and medicinal chemistry areas. In our previous works, we have shown the iron (III) selective on-off sensor properties of benzo[c]chromen-6-one derivatives. In this study, we have extrapolated this research to 4-substituted analogues and investigated both fluorescent and metal interaction properties. Following the synthesis and structure identification studies, (±)-7,8,9,10-tetrahydro-3-hydroxy-4-(1-hydroxyethyl)benzo[c]chromen-6-one was found as a fluorescent molecule displaying fluorescence enhancement in the …

Intrinsically Fluorescent And Quercetin Loaded Highly Crosslinked Polyphosphazene Nanospheres: Synthesis, Characterization And Fluorescence Properties, Si̇mge Meti̇noğlu Örüm

Turkish Journal of Chemistry

Highly crosslinked, inorganic-organic hybrid and intrinsically fluorescent polyphosphazene nanospheres bearing hydroxyl groups on the surface are facilely generated via a one-pot polycondensation of octachlorocyclotetraphosphazene, fluorescein and quercetin. The resulting nanospheres were characterised by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), X-ray diffraction analysis (XRD) and ultraviolet-visible spectroscopy (UV-vis) techniques. The average diameter of the nanospheres was determined as 379 nm. Also, quercetin which is both a monomer and an anticancer drug was loaded to the nanospheres as 446 mg g-1. The obtained nanospheres possess outstanding disperse ability in both aqueous …

Development Of Dual Enzyme Responsive Molecular And Logic Gate, Sündüs Erbaş Çakmak

Turkish Journal of Chemistry

Molecular logic gates are information processing devices that can respond to environmental signals and produce a readable output in response through Boolean logic operations. Molecules with these properties have been used to build smart sensors and therapeutic agents. In this work, dual enzyme-responsive molecular AND logic gate is developed with the intention to discriminate various combinations of enzyme level and/or activity. A resorufin-based sensor is substituted with self-immolative tyrosinase recognition site, 3-hydroxy benzyl group. The Hydroxyl group is protected with acetyl moiety which decreases the affinity of the enzyme. When both tyrosinase and esterase are present in the solution, the …

Optimizing The Fluorescent Quantum Yield Of Carbon Dots, Megan B. Prado

MSU Graduate Theses

Carbon dots (CDs) are a subclass of carbon nanomaterials that exhibit unique properties of fluorescence, photostability, low toxicity, and biocompatibility. These unique properties have enabled numerous applications including biosensing, heavy-metal detection, and pH-sensing, among others. Their optical properties can be modified via doping to produce increasingly fluorescent CDs after appropriate purification. Herein, doped CDs were synthesized in four bottom-up methods for comparison using sucrose or citric acid as carbon precursors. Varying hetero-atom dopants (N, S, B) were used in differing molar ratios. The pH-dependent fluorescence and fluorescent quantum yield (QY) were measured for each sample. Characterization was conducted using Fourier-Transform …

Total Internal Reflection: Applications In Nonlinear Microscopy And Fluorescence Anisotropy, Brandon Colon

Doctoral Dissertations

As technology advances to harness new energies and to create new cures, the sophistication of analysis grows not only in depth but in efficiency. Total internal reflection (TIR) has been coupled to microscopy leveraging its unique optical phenomenon on a breadth of topics. In this dissertation, the work presented will show how TIR was applied in two different instrumental analyses to evaluate two unique and complex systems. The first project features TIR paired with the transient absorption microscopy (TAM), a nonlinear optical technique, to gauge solvent mixing and diffusion in microreactors. Microreactors gained acclaim for their ability to produce high …

Instrument Development For High Sensitivity Size Characterization Of Lipid Vesicles And Other Biological Macromolecules Via Taylor Dispersion Analysis, Meagan Moser

Doctoral Dissertations

Just as humans communicate with other humans, the cells in our bodies communicate with each other through various, often complex, mechanisms. Cell-to-cell transmission of small molecules, lipids, proteins, peptides, or nucleic acids can be mediated by extracellular lipid vesicles called exosomes. Exosomes have been found to play a role in the delivery of regulatory molecules from one cell to another, serving as a universal communication mechanism. Currently, there is an emerging focus on characterizing exosome communication dynamics. Understanding exosome mechanisms of cell-to-cell communication requires accurate measurements of the spatiotemporal and chemical dynamics of exosome secretion. No current analytical approach offers …

Preparation And Study Of Bacterial Membrane Models, Enoch Asimbisa

Electronic Theses and Dissertations

Fuel molecules are organic solvents that have disruptive effects on the bacterial membrane. This is a significant barrier in biofuel production, as it limits the fuel concentration that can be achieved through fermentation. One potential way of overcoming this barrier is to identify lipid compositions that can better withstand solvent stress, for which it is important to understand how organic solvents disrupt the membrane. Use of biophysical characterization techniques to quantify physical properties like fluidity and thickness will enable us to understand the mechanism by which solvents disrupt membranes. Native membranes are very complex, and we sought to develop in-vitro …

Synthesis And Characterization Of Re(I) Tricarbonyl Complexes Of 1,8-Naphthalimide, Priyanka Jagadeesa Prabhu

Electronic Thesis and Dissertation Repository

1,8-Naphthalimide fluorophores with amino-substituents absorb and emit in the visible region. The photophysical properties of this class of fluorophores can be modulated by altering the degree of Intramolecular Charge Transfer (ICT) in the excited state. Thus, several metal complexes with the 1,8-naphthalimide motif have been developed as cell imaging agents. In this project, four 1,8-naphthalimide ligands were synthesized by incorporating rigid linkers. Among these, three ligands also allowed the extension of π-conjugation to the naphthalimide moiety. In addition, a ligand was also synthesized without the use of a linker. Re(I) tricarbonyl complexes of these ligands were also synthesized and their …

Part I: Development Of Small-Molecule-Based Probes For The Vitamin D Receptor; Part Ii: Development Of A Scalable Manufacturing Process For Orcein Dye, Tania Roseann Mutchie

Theses and Dissertations

PART I:The vitamin D receptor (VDR) is a ligand-dependent transcription factor and member of the nuclear hormone receptor superfamily. VDR is expressed in the epithelia of endocrine organs, digestive system, bronchi, kidneys, and thymus, as well as being present in leukocytes and bone cells. Cell proliferation, cell differentiation, and immunomodulation, along with calcium and phosphate homeostasis, are all processes regulated by the receptor. Within the cell, VDR can be membrane-bound or located in the nucleus. Nuclear localization of VDR transpires following the binding of vitamin D metabolites, the most active of which is 1α,25-dihydroxyvitamin D3 (calcitriol). Within the nucleus, interactions …

Biomedical Applications And Syntheses Of Selected Anthraquinone Dyes, Richard Sirard

Senior Honors Theses

Anthraquinones are aromatic organic compounds that have multiple applications in the biomedical field. Some anthraquinone-based compounds are used as fluorophores to contrast cell nuclei while others act as chemotherapeutic agents. However, there are not many fluorescent anthraquinone cell stains currently available. In this study, commercially available anthraquinone dyes, in addition to other dye families and compounds, were reviewed for their unique properties, advantages, and drawbacks. The development and characterization of three novel anthraquinone fluorophores revealed promising photophysical characteristics, like large Stokes shifts. One of the compounds, RBS3, was chosen for fixed and live cell staining and exhibited desirable biomedical properties. …

Indolizine Donor-Based Dyes For Applications In Fluorescence Biological Imaging, William Meador

Honors Theses

NIR emissive fluorophores are intensely researched due to their potential to replace modern imaging procedures. Many molecular strategies have been employed in the literature to optimize fluorophores for deeper NIR absorption and emission, biocompatibility, and higher fluorescence quantum yields. Amongst the fluorophores studied to date, proaromatic indolizine donors are attractive alternatives to traditional alkyl amine and indoline based donors due to their 1) lower energy absorption and emission facilitated by proaromaticity, 2) large Stokes shifts due to increased dihedral angles about the π-system, 3) ease of functionalization and capacity for bioconjugation at the phenyl ring, and 4) potential for further …

Beneficial Impacts Of Incorporating The Non-Natural Amino Acid Azulenyl-Alanine Into The Trp-Rich Antimicrobial Peptide Bucathl4b., Areetha R D'Souza, Matthew R Necelis, Alona Kulesha, Gregory A. Caputo, Olga V Makhlynets

Faculty Scholarship for the College of Science & Mathematics

Antimicrobial peptides (AMPs) present a promising scaffold for the development of potent antimicrobial agents. Substitution of tryptophan by non-natural amino acid Azulenyl-Alanine (AzAla) would allow studying the mechanism of action of AMPs by using unique properties of this amino acid, such as ability to be excited separately from tryptophan in a multi-Trp AMPs and environmental insensitivity. In this work, we investigate the effect of Trp→AzAla substitution in antimicrobial peptide buCATHL4B (contains three Trp side chains). We found that antimicrobial and bactericidal activity of the original peptide was preserved, while cytocompatibility with human cells and proteolytic stability was improved. We envision …

Synthesis And Self-Assembling Properties Of Peracetylated Β-1 Triazolyl Alkyl D Glucosides And D-Galactosides, Pooja Sharma, Anji Chen, Dan Wang, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Carbohydrate-based low-molecular-weight gelators (LMWGs) are useful classes of compounds due to their numerous applications. Among sugar-based LMWGs, certain peracetylated sugar beta-triazole derivatives were found to be effective organogelators and showed interesting self-assembling properties. To further understand the structural influence towards molecular assemblies and obtain new functional materials with interesting properties, we designed and synthesized a library of tetraacetyl beta-1-triazolyl alkyl-D-glucosides and D-galactosides, in which a two or three carbon spacer is inserted between the anomeric position and the triazole moiety. A series of 16 glucose derivatives and 14 galactose derivatives were synthesized and analyzed. The self-assembling properties of these new …

Plasmon Enhanced Single Molecule Fluorescence In Zero Mode Waveguides (Zmws), Abdullah Masud

Theses and Dissertations--Chemistry

Plasmonic nanostructures are an extensive research focus due to their ability to modify the photophysical properties of nearby fluorophores. Surface plasmons (SP), defined as the collective oscillation of delocalized electrons, are the fundamental characteristic primarily responsible for altering those photophysical properties. Studying fluorophores at the single-molecule level has received significant attention since more specific information can be extracted from single molecule-based studies, which otherwise could be obscured in ensemble studies. However, single-molecule studies are inherently challenging because the signal from a single molecule is usually dim, making it difficult to detect. The situation is even worse in a crowded environment …

Identification Of Compounds Causing Cellular Autofluorescence In Touch Samples, Elora C. Wall

Master of Science in Forensic Science Directed Research Projects

As DNA analysis has advanced and produced tests with higher sensitivities, attention has turned toward obtaining DNA profiles from cells left with fingermarks. Recent studies have reported that cells deposited within fingermarks can exhibit differences in autofluorescence emission in the ‘red’ region of the visible spectrum (e.g., between 650-670 nm), which can be used to differentiate contributor cell population and separate them before DNA profiles. Interestingly, this emission was not consistent to the individual day-to-day and likely not a genetically-controlled attribute of the contributor. Instead, this emission signature results from extended exposure of the skin to certain materials such as …