Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Study of Drug Transportation by Esr Spectroscopy(Izmir Institute of Technology, 2018) Tatlıdil, Duygu; Akdoğan, Yaşar; Emrullahoğlu, MustafaThe ability to track drug binding and release makes electron spin resonance (ESR) spectroscopy well suited for drug delivery studies. Using the continuous wave cw ESR technique to extract information about the dynamics of the spin labeled drugs we can simultaneously determine the bound and unbound drugs. In this study, ESR technique was used to detect the binding and release of spinlabeled salicylic acid (SLSA) to and from bovine serum albumin (BSA), and to detect different binding interactions between them. We have labeled salicylic acid with stable nitroxide-based tempo radicals to monitor the BSA bound and unbound conditions of the drug. Studying with the different concentrations of SLSA-BSA binding showed that the drug-protein stoichiometry increases significantly in the physiological range of BSA concentration. Also, during the release of SLSA from BSA, there is an unchanging balance between the bound and unbound SLSA. In order to study various drug binding interactions, SL-benzoic acid, SL-phenol, SL-benzene, SL-cyclohexane, SL-hexane and SL-methyl were prepared. We showed that the main conjugation in the binding of these drugs to BSA is hydrophobic interaction. In addition, cationic BSA (cBSA) was prepared to investigate the effect of electrostatic interaction on drug binding. The SLSA loading capacity of cBSA is significantly higher than that of BSA, this result indicates the importance of electrostatic interactions for the drug binding. Finally, we examined the competitive binding behaviors of salicylic acid, ibuprofen and aspirin to BSA. Binding sites of SL-salicylic acid and SL-ibuprofen in BSA show 96% of similarities. In addition, our results showed that binding sites of SL-salicylic acid and SL-aspirin in BSA have 73% of similarities.These results demonstrate that cw ESR spectroscopy with the spin labeling technique is an effective technique for the determination of drug-protein interactions and stoichiometric analysis of drug binding.Master Thesis Measurement of Transition Metals in Soda-Lime Glasses by Using Electron Spin Resonance (esr) Spectroscopy(Izmir Institute of Technology, 2017) Göktürk, Hakan; Akdoğan, Yaşar; Adem, UmutElectron spin resonance (ESR) spectroscopy does not appear to have found a wide use when compared with other structural analysis methods, especially spectroscopy techniques, utilized in the glass industry. The method, however, provides a good means for supporting the structural information obtained from other spectroscopic methods. Because of its ability to detect and differentiate the paramagnetic ions at low concentrations, ESR spectroscopy is commonly used as a quantitative and qualitative analysis method for evaluating transition metals. This study showed the behavior and interaction of paramagnetic 3d transition metal ions using ESR spectroscopy for the soda-lime-silicate based glasses. For this reason, it revealed the existence of paramagnetic (Fe3+, Cr3+, Mn2+ and Cu2+) transition metal ions in soda-lime-silicate glass and their spectral trends studied at addition levels up to 2.0% mol. Additionally, ESR spectra of Fe3+-Cr3+, Fe3+-Mn2+ and Fe3+-Cu2+ added soda-lime-silicate glass samples were studied to show the effects of the different transition metals on Fe3+ containing glasses. The final point of study is that the approach to quantify the ESR spectra with the concentration of paramagnetic metal ions in glass. In this way, this study gives structural information about the used glass and so lightens the locations of used metal ions.Master Thesis Obtaining Underwater Adhesive Materials and Characterization of Their Adhesive Properties To Different Surfaces by Esr Spectroscopy(Izmir Institute of Technology, 2016) Kırpat, İklima; Akdoğan, YaşarThis study describes the design, synthesis and spectral behavior of underwater adhesive materials which adhere to surfaces without any external force. The materials with wet adhesive properties have a wide application field from biomedical implantation and covering to antifouling materials. Mussel’s stickiness to rocks, ships, etc. inspite of strong waves in the sea inspires us to synthesize adhesives materials. Mussels attach to solid surfaces strongly using their threads and plaques. The complex fluid (mussel foot proteins, Mfps) secreted from mussels is solidified in the sea water and forms threads, each equipped with a distal adhesive plaque. Mfps have large amount of L-3,4-dihydroxyphenylalanine (DOPA) amino acid and this amino acid is responsible for adhesion of mussels to underwater surfaces. The presence of stable hydration layers around both the adhesive materials and surface results in strong hydration repulsive forces that undermine adhesion. So far, applied external forces were used to break through or disrupt the hydration layers which prevent adhesion. In this research branched PEG based polymers were modified with different amounts of DOPA in order to obtain underwater adhesive material. Their adhesive properties to spin labeled (SL) nanoparticles were tested without applying an external force by electron spin resonance (ESR) spectroscopy. As model surfaces we synthesized hydrophobic SL-polystyrene and hydrophilic SL-silica nanoparticles. ESR results showed that four arm DOPA modified PEG is able to adhere to SL-polystyrene but not to SL-silica. Moreover, adhesions of the polymers were tested by making hydrogels using iodate (IO3-) and iron (III) (Fe3+) ions. ESR results showed that hydrogels prepared from four arm DOPA modified PEG/IO3- mixture has better adhesive property to SL-polystyrene compare to hydrogels prepared from four arm DOPA modified PEG/Fe3+ mixture and adhesion of IO3- based gel form is better compared to molecule form.