Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Author: search.filters.author.Demir, Mustafa MuammerSubject: search.filters.subject.Nanoparticles

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Now showing 1 - 5 of 5
  • Master Thesis
    Preparation and Characterization of Serum Albumin Nanoparticles Obtained From Modified Bovine Serum Albumin
    (01. Izmir Institute of Technology, 2021) Özmen Egesoy, Tuğçe; Akdoğan, Yaşar; Demir, Mustafa Muammer
    The serum albumin has been used as a drug nanocarrier for a long time due to its rich drug transportation ability. Here, modified bovine serum albumin (BSA) proteins were obtained by conjugation with ethylenediamine and dopamine molecules, separately. Using these modified proteins, new BSA nanoparticles were obtained by a desolvation method. Native BSA has a net negative charge at the physiological condition. However, ethylenediamine conjugation yields a positive charge on it, and thus produces cationic BSA (cBSA) protein. On the other hand, dopamine functionalization (D-BSA) makes BSA eager to coordinate with transition metals. After preparation of modified proteins (cBSA and D-BSA), their nanoparticles were prepared with desolvation method but using different crosslinking mechanisms. For cBSA NPs preparation, a traditional crosslinking agent of glutaraldehyde was used. However, for D-BSA NPs preparation, Fe(III) ions were added to the system to achieve the stable nanoparticle formation. In order to obtain cBSA NPs, several organic solvents were used as desolvating agents. cBSA NPs with an average size around 200 nm were obtained in a high formation yield (54.8%) only through addition of acetonitrile to the cBSA aqueous solution. Similarly, different desolvating agents were studied to obtain D-BSA NPs. The promising results were obtained upon addition of 1:5 (v/v) of water/acetone mixture. After addition of the desolvating agent, Fe(III) ions were added to the solution to interconnect D-BSA with each other. This connection is pH sensitive therefore albumin nanoparticles were stable at basic pH values but not at acidic pH values. By this way, pH sensitive D-BSA NPs around 300 nm particle sizes were obtained.
  • Master Thesis
    Chitosan-Plasmid Dna Nanoparticles: Cytotoxic and Cytostatic Effects on Human Cell Lines
    (Izmir Institute of Technology, 2015) Bor, Gizem; Şanlı Mohamed, Gülşah; Demir, Mustafa Muammer
    Although chitosan nanoparticles (CNs) became a promising tool for several biological and medical applications owing to their inherent biocompatibility and biodegrability, studies regarding their effects on cytotoxicity and cytostatic properties still remain insufficient. Therefore, in the present study, we decided to perform comprehensive analysis of the interactions between CNs – pKindling-Red-Mito (pDNA) and different cell line models derived from blood system and human solid tissues cancers. The resulting CNs-pDNA was investigated with regard to their physical-chemical properties, cellular uptake and transfection efficiency, cytotoxic and cytostatic properties. The nanoparticles showed high encapsulation efficiency and physical stability even after 2 days for various formulations. Moreover, high gene expression levels were observed already 96 h after transfection. CNs-pDNA treatment, despite the absence of oxidative stress induction, caused cell cycle arrest in G0/G1 phase and as consequence led to premature senescence, which turned out to be both, p21-dependent and p21-independent. Also, observed DNMT2 upregulation may suggest the activation of different pathways protecting from the resulting CNs-mediated stress. In conclusion, treatment of different cell lines with CNs-pDNA showed that their biocompatibility was limited and effects were cell type-dependent.
  • Master Thesis
    Selective Loading of Organofilic Ag Nanoparticles in Ps-Pmma Blends
    (Izmir Institute of Technology, 2014) Tüzüner, Şeyda; Demir, Mustafa Muammer; Ebil, Özgenç
    The association of nanoparticles with polymer blends offers significant features beyond the advantages of polymer composites prepared by single homopolymer. Since the blends undergo phase separation due to incompatibility of the constituent polymers into various internal structures, the particles can be segregated into one of the phases. Different location of the particles allows to develop novel microstructures; and thus, control over physical properties. In this study, Ag nanoparticles were prepared by reduction of AgNO3 via NaBH4. The particles were capped by cetyl ammonium bromide (CTAB) and were mixed with equimass blend of polystyrene (PS) and poly(methyl methacrylate) (PMMA) in tetrahydrofurane (THF). The solid content of blend solution was fixed at 2.5% w/v. The concentration of the particles with respect to polymer blend was at 0.7 wt %. The composite film was cast on glass slide. Surface feature of the composite films was examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The surface of blend film without particles shows spherical pits with a size of 4.5 μm and rich in terms of PMMA. When particle size was small (diameter is around 20 nm), they preferentially located at the interface of the domains. The large particles with a diameter of 90 nm were found to locate in PMMA phase. Upon annealing of the composite film at 165 ˚C for 3 days, the particles move to the PS domains independent of the particle size and merely PS loaded composite is achieved.
  • Master Thesis
    Development of Whey Protein Isolate Based Nanocomposite Food Packaging Film Incorporated With Chitosan and Zein Nanoparticles
    (Izmir Institute of Technology, 2014) Oymacı, Pelin; Alsoy Altınkaya, Sacide; Demir, Mustafa Muammer
    The purpose of this study was to investigate the effect of chitosan and zein nanoparticles addition on the barrier and mechanical properties of whey protein isolate (WPI) films as an alternative to conventional synthetic packaging materials. Chitosan nanoparticles (CSNP) were produced via ionic gelation method using sodium tripolyphosphate (TPP) and deacetylated chitosan. Zein nanoparticles (ZNP) were synthesized based on antisolvent procedure in the presence of sodium caseinate (SC) to enable dispersion in water. Both plain and nanoparticle added WPI films were prepared by solution casting method. Water vapor barrier and mechanical properties of films were measured and the improvements in these properties with nanoparticle addition was further investigated through surface wetting, morphological, viscoelastic and thermal properties of the films. Both nanoparticles significantly decreased the water vapor permeability (WVP) and improved the mechanical properties of the WPI film. The highest enhancement in barrier and mechanical properties of the WPI films were recorded with 20% (w/w of WPI) CSNP and 120% (w/w of WPI) ZNP addition which corresponded to the maximum nanoparticle loading levels. At these loadings, the average WVP of pure WPI films loaded with ZNP and CSNP decreased by 84% and 57%, and the average tensile strength increased by 304% and 161%, respectively. On the other hand, the nanoparticles did not change the elongation at break significantly. ZNP was found more effective than CSNP in improving barrier and mechanical properties of the WPI films due to its hydrophobic nature and better dispersion in the protein matrix which allowed much higher loadings compared with the maximum loading levels achieved with CSNP. CSNP addition imparted antibacterial activity to the WPI films.
  • Master Thesis
    Preparation of Electrospun Composite Fibers Based on Ps-pi-ps/Cdsxse1-x Nanoparticles
    (Izmir Institute of Technology, 2011) Aşkın, Görkem; Demir, Mustafa Muammer; Özçelik, Serdar
    Polymeric fibrous films were prepared based on polystyrene-b-polyisoprene-bpolystyrene triblock copolymer (SIS) and CdSxSe1-x nanoparticles by electrospinning process. SIS with 14 wt % Styrene (14% PS-SIS) and 22 wt % Styrene (22% PS-SIS) triblock copolymers were employed. Both of them undergo microphase separation. While the former shows cylinder-like morphology, the latter exhibits the lamellae one. CdSxSe1-x partciles were stabilized by two different surfactant molecules: i) n-trioctylphosphine oxide (TOPO) and ii) oleic acid (OA). When the particles were blended with 22% PS-SIS, particles capped with TOPO preferentially filled to PS domain whereas particles capped with OA loaded into the PI domain. Composite electrospun fibers were prepared with a diameter of 1.5 mm on average. Electrospinning parameters (potential difference, solution concentration, flow rate) were investigated on fiber morphology. The films are colorless under day light and have strong green emission under UV light.