1,720,987 research outputs found
Characterizing the thermodynamic parameters of anti-cancer drug Carboplatin and DNA through Spectroscopic techniques
No full textSpectroscopic techniques have been employed to understand the interactions and thermodynamic parameters between the anti-cancer drug Carboplatin and the DNA oligomer COTAR 2: ATT AAT GGA TCC ATT AAT. This is a self-complementary sequence that has been previously shown to bind [Co(NH3)2(OH2)2]+3 with high specificity and is of interest because it contains two isolated G-G sites. Both Cisplatin and Carboplatin are known for binding preferentially to G-G sites. These anti-cancer drugs are commonly used in chemotherapeutic treatments and are known to have adverse side effects. In order to improve treatment options, it’s necessary to understand the molecular basis of their interactions with DNA. The binding of Carboplatin with COTAR 2 has been analyzed using Circular Dichroism (CD), Surface−Enhanced Raman Scattering (SERS), and UV-Vis Spectroscopy. The combination of these techniques allows for better understanding of structure and stability of platinum-DNA complexes, as well as binding kinetics. In this thesis, the results of these studies will be presented, and our current understanding of this interaction will be discussed
Bringing photodegradation of plastic waste into the “green age” through off-grid sustainable energy
No full textPlastic pollution continues to be a problem despite the current efforts in physical and chemical recycling. Moreover, the faster turnover rate on electronic devices by all consumers continues to increase the generation of plastic waste; consequently, the pollution generated also increases worldwide. Despite breakthroughs that have been achieved, the chemical recovery of complex plastics is still a difficult challenge plaguing society today. Some newer approaches for its management are starting to surge; in fact, one recent example is the use of photochemical degradation as a way of breaking down complex polymers such as those found in category 7 of the resin code. While photodegradation of these polymers has seen significant findings over the years, it remains economically costly, and limited to the laboratory scale. This project introduces the preliminary findings of our own implementations of potential “greener” alternatives to the typical photochemical methodologies while also sharing the design process for increasing photodegradation efficiency. By making use of renewable energy light sources that are commercially available we present our prototypes of an off grid photoreactor. The photo-oxidation results gathered in the study will not only prove that these green methods are practical but also act as the first step for introducing a more sustainable form of photodegradation for polymers, which is not only eco-friendly but cost effective for future potential commercial applications
Synthesis of doxorubicin-protein conjugates via cobalt coordination chemistry
No full textThe use of nanotechnology-based drug delivery systems in the context of cancer treatments has the potential to help target drug chemotherapeutics to tumor cells more precisely while simultaneously reducing off-target toxicity. One of the most prescribed chemotherapeutics, doxorubicin, is an anthracyclines drug that is effective in treating cancer; however, the drug exhibits dose-limiting cardiotoxicity. Dox intercalates DNA, resulting in the deterioration of DNA strands and the ultimate inhibition of DNA and RNA synthesis. Doxorubicin’s chemical structure contains a primary amine group that can be used to crosslink it to a protein. This project focuses on using cobalt coordination chemistry as a novel crosslinking strategy to synthesize conjugates of Dox bound human serum albumin (HSA). The synthesis of conjugates of Dox with HSA will be discussed along with methods for characterization via HPLC that allow the number of Dox molecules bound per protein molecule to be determined
Syntheses and characterizations of homoleptic and heteroleptic copper complexes with monocyclic and polycyclic azine ligands
No full textThis thesis is concerned with the following ligands to use to coordinate and react to copper: a pyrimidine: niacinamide, the polyazine monocyclic triazine: cyanuric acid, and bicyclic N- donating hydrocarbons: quinoxaline and caffeine. When reacted with cuprous salts consisting of organic ligands they form multi-ligand coordination supramolecular architectures (1) or halides to form copper halide clusters. In the novel compounds, metal-metal interactions occur, which exhibit low-lying triplet state charge transfers, allowing the tunability of a photon-emitting compound which is expected to form the emission. Cuprous metal centers also possess the ability to self-assemble to form coordination polymers. Group 11 d10 coinage metals exhibit strong metal-to-ligand charge transfers (MLCT) as well.(50) Characterization of all compounds was completed using thermogravimetric analysis, X-ray crystallography, Fourier transform infrared spectroscopy (FTIR), and photoluminescence spectroscopy. The acquired data is analyzed and discussed further in the following thesis
Synthesis of doxorubicin-protein conjugates via cobalt coordination chemistry: Conjugates of transferrin and immunoglobulin G
No full textProtein-drug conjugates are a rapidly expanding family of therapeutics that hold significant potential to ameliorate off-target toxic effects commonly observed in patients undergoing chemotherapy. chemotherapy. In this context, the protein acts as a nanoscale delivery vector that alters the biodistribution of the drug upon administration by restricting its unhindered distribution in vivo. This thesis explores the use of cobalt coordination chemistry in the synthesis of doxorubicin-protein conjugates. Previous work has shown that cobalt can be used to crosslink amine-containing molecules in a reversible reaction that only utilizes the lone pair of electrons on nitrogen to form a dative bond with cobalt. Doxorubicin was chosen for initial studies because it contains a primary amine that could be crosslinked with lysine residues on a protein to form a protein-drug conjugate. Conjugates of dox with albumin, transferrin, and immunoglobulin G were investigated to demonstrate the broad applicability of the method for bioconjugation reactions. Drug loading was investigated by HPLC, and the conjugates further characterized by dynamic light scattering, calorimetry, and cytotoxicity. Details of the effects of reaction conditions on synthesis of stable conjugates will be discussed
The characterization of pristine and functionalized carbon nanotubes and their dispersion in solvents
No full textCarbon nanotubes (CNTs) are unique nanotubes with a vast array of applications due to their unique thermal, mechanical, and electrical properties. The structure and size of these CNTs can vary, affecting their properties and thus applications. The characterization of this material is needed to better understand how different variables affect their properties as measured through instrumental analysis. In this study we examine how diameter, outer wall layering, functionalization, and dispersion in solvents affect the spectral analysis of CNTs. We then attribute these spectral changes to the CNT unique properties. We found that a combination of increased sonication time and prolonged saturation of CNTs in solvents result in significant shift of their Raman spectra. Additionally, we found that the electrical properties of CNTs play a significant role in the spectra peaks. This research has implications in using these mechanical properties for sensors and conductors in medical devices
Synthesis and characterization of diverse copper halide complexes with a range of heterocyclic ligands
No full textThis study aimed to compare the stability, physical, and chemical attributes of Cu(I) and Cu(ACN) metals, investigating their resemblances and disparities. It comprises approximately 137 pages, encompassing 90 figures, 16 tables, and references. The research focused on synthesizing and characterizing Cu(I) complexes with azole family ligands. Two methodologies were applied: the first involving CuI and Cu(CH3CN) (where X = I or CH3CN) reacting with single ligands like 3,5-diisopropylpyrazole, 3,5-diphenolpyrazole, 3,5-(tert)-butylpyrazole, and 5-(4-chlorophenyl)-1H-tetrazole. The second utilized Cu(CH3CN) with mixed ligands specifically 3,5-diphenolpyrazole and pyrazine, as well as 3,5-(tert)-butylpyrazole and pyrazine. Complex synthesis occurred via solvent-mediated routes using the Schlenk technique and solvent-free reactions with mechanical grinding. Comprehensive characterization involved techniques such as melting point determination, solubility tests, luminescence spectroscopy, FT-IR, TGA, elemental analysis, NMR, and X-ray crystallography. Ligands were characterized using the same listed techniques to understand changes. All synthesized products underwent thorough characterization using diverse analytical tools
Surface interactions of polyethylene microplastics and sodium laureth ether sulfate
No full textThe characterization and identification of Sodium Laureth Ether Sulfate (SLES) and polyethylene microbeads (PE microbeads) were carried out using FTIR, ¹H-NMR, DLS, and titrations. FTIR and ¹H-NMR were employed to assess the structural integrity of SLES and PE microbeads. To determine whether SLES could physically interact with the PE microbeads, DLS was performed. Since SLES is a weak base, acetic acid was used to titrate the solution, and both conductivity and pH were measured. The analysis revealed that at low concentrations, the SLES solution showed large particle sizes with low intensity. As the concentration increased from the critical micelle concentration (CMC) of SLES to eight times the CMC, the particle size decreased and the intensity increased. When PE microbeads (ranging in size from 10 to 62 μm were added, they were detectable at lower concentrations, but as the concentration of SLES increased, the intensity of the PE microbeads also decreased. The titration results demonstrated that a strong acid, at high concentrations, effectively breaks down SLES, allowing the PE microbeads to be re-detected
HPLC analysis to assess efficacy of cisplatin, nedaplatin, and oxaliplatin
No full textPlatinum drugs are one of the most widely used agents against cancerous cells. Cisplatin’s chemotherapeutic efficacy is limited by the increase of tumor resistivity and unwanted side effects. Cisplatin’s cytotoxicity is linked to its ability of forming 1,2-intrastrand adducts with adjacent guanine (G) bases. An analytical method to detect and quantify the amount of platinum bound to DNA is necessary to enhance and develop anticancer drugs. In this work, High Performance Liquid Chromatography (HPLC) analysis was performed to assess the binding of cisplatin, nedaplatin, and oxaliplatin to the dinucleotide dGpdG. By examining the concentration ratios and incubation periods at 37 °C, we measured the amount of platinum drug reacted with DNA (platination rates) indicating the percentage of Platinum-DNA (Pt-DNA) adducts. Cisplatin proved to be the most effective, followed by nedaplatin, and then oxaliplatin. This research has implications in designing more efficient anticancer drugs
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