Aydemir, Umut
Boron Neutron Capture Therapy (BNCT) is a non-invasive radiotherapy technique which is based on delivery of non-radioactive 10B compounds to cancer cells and irradiation of the tumour tissues with low energy thermal neutrons. It is a promising radiotherapy technique due to reduce the side effects of the treatment. The main goal of this thesis is to prepare a non-toxic polymer vehicle to provide efficient delivery of 10B to cancer cells. Dodecahydro-closo-dodecaborate (B12H12)2- (B12) anion was utilized as a model 10B containing agent because of its high boron concentration. Quaternized poly(2-vinyl pyridine)-b-poly(ethylene oxide) (QP2VP-b-PEO) was chosen as a model neutral-cationic block copolymer to construct the carrier. The electrostatic association between QP2VP and B12 induced self-assembly of QP2VP-b-PEO, resulting in micelles with (B12+QP2VP)-core and PEO-corona. (B12+QP2VP)-b-PEO micelles were found to be not stable against dilution in biological medium. Layer-by-Layer (LbL) deposition technique was used to self-assemble these micelles onto colloidal CaCO3 microparticles to enhance their stability. Tannic acid (TA) was used to drive the LbL assembly through hydrogen bonding interactions between hydrogen accepting PEO-corona and hydrogen donating TA. Stability of LbL capsules in biological medium was assured by construction of barrier layers composed of poly(N-vinyl-caprolactam) (PVCL) and TA on top of (B12+QP2VP)-b-PEO micelles and TA multilayers. Cytotoxicity and cellular association of LbL capsules was assessed in non-hollow and hollow form using Hep G2 cell line. Capsules were found to show no systematic cytotoxicity on Hep G2 cell line. Cellular association studies and boron concentrations determined through inductively coupled plasma optical emission spectroscopy (ICP-OES) showed that both non-hollow and hollow capsules associated with Hep G2 cells and delivered boron to the cells. Overall, this study generated fundamental knowledge on B12 induced micellization and stabilization of micelles in biological medium. These findings may form a basis to develop polymer carriers for boron delivery for BNCT.


Preparation and labeling of surface-modified magnetoferritin protein cages with a rhenium(I) carbonyl complex for magnetically targeted radiotherapy
Aslan, Tugba Nur; Asik, Elif; Volkan, Mürvet (Royal Society of Chemistry (RSC), 2016-01-01)
New rhenium radiolabeled compounds are of general interest due to their nuclear characteristics which allow radiotherapy and in situ monitoring of tumor uptake. Biocompatible magnetic nanoparticles capable of transporting radionuclides, providing MRI contrast agent properties for imaging and a therapeutic effect in the target tissue simultaneously, are highly desirable. Herein we describe the preparation of magnetoferritin samples, and their labeling with rhenium in the form of the low oxidation state rheni...
Interaction of tomato lectin with ABC transporter in cancer cells: Glycosylation confers functional conformation of P-gp
Molnar, Joseph; Kars, Meltem Demirel; Gündüz, Ufuk; Engi, Helga; Schumacher, Udo; Van Damme, Els J.; Peumans, Willy J.; Makovitzky, Josef; Gyemant, Nora; Molnar, Peter (2009-01-01)
Phospho-glycoprotein (P-gP) is a polytopic plasma membrane protein whose overexpression causes multidrug resistance (MDR) responsible for the failure of cancer chemotherapy. P-gp 170 is a member of the ATP-binding cassette (ABC) transporter superfamily and has two potentially interesting regions for drugs interfering with its efflux function, namely the oligosaccharides on the first extracellular loop with unknown function and the two intracellular ATP-binding regions providing the energy for drug efflux fu...
Layer-By-Layer Modified Superparamagnetic Iron Oxide Nanoparticles with Stimuli-Responsive Drug Release Properties
Akbar, Majid; Çağlı, Eda; Erel Göktepe, İrem (2019-02-01)
Superparamagnetic iron oxide nanoparticles (SPIONs) are synthesized through ultrasound based coprecipitation method. SPIONs are coated with poly(2-isopropyl-2-oxazoline) (PIPOX) and tannic acid (TA) in a layer-by-layer (LbL) fashion at pH 4 and 25 degrees C. PIPOX/TA coated SPIONs are then loaded with doxorubicin (DOX) at pH 7.5 and 25 degrees C. DOX release from LbL-coated SPIONs is examined at pH 7.5 and pH 6 at 25 degrees C, 37 degrees C, and 42 degrees C. LbL-coated SPIONs exhibit dual responsive behavi...
Synthesis of zinc oxide nanoparticles elaborated by microemulsion method
Yildirim, Ozlem Altintas; Durucan, Caner (2010-09-17)
Zinc oxide (ZnO) nanoparticles were synthesized by a reverse microemulsion system formed from sodium bis(2-ethylhexyl)sulfosuccinate (Aerosol OT, or AOT):glycerol:n-heptane. The zinc precursor was zinc acetate dihydrate. The formation of ZnO nanoparticles was achieved by calcination of premature zinc glycerolate microemulsion product in air at 300, 400 and 500 degrees C. The crystal structure and the morphology of the ZnO nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron micr...
Synthesis of Some Substituted 6-Phenyl Purine Analogues and Their Biological Evaluation as Cytotoxic Agents
Kucukdumlu, Asligul; Tuncbilek, Meral; Guven, Ebru Bilget; Atalay, Rengül (2017-01-01)
A series of 6-(4-substituted phenyl)-9-(tetrahydropyran-2-yl) purines 3-9, 6-(4-substituted phenyl) purines 10-16, 9-((4-substituted phenyl) sulfonyl)-6-(4-substituted phenyl) purines 17-32 were prepared and screened initially for their in vitro anticancer activity against selected human cancer cells (liver Huh7, colon HCT116, breast MCF7). 6-(4-Phenoxyphenyl) purine analogues 9, 16, 30-32, had potent cytotoxic activities. The most active purine derivatives 5-9, 14, 16, 18, 28-32 were further screened for t...
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