Master Degree / Yüksek Lisans Tezleri

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

Browse

Filters

2007 - 200912010 - 201942020 - 20233

Settings

Department: search.filters.department.Thesis (Master)--İzmir Institute of Technology, Materials Science and EngineeringSubject: search.filters.subject.Nanoparticles

Search Results

Now showing 1 - 8 of 8
  • Master Thesis
    Synthesis of Drug Loaded Ph Sensitive Albumin Nanoparticles
    (2023) Adem, Umut; Akdoğan, Yaşar; Akdoğan, Yaşar; Adem, Umut; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Serum albumin-based nanoparticles (NPs) are commonly used for drug delivery due to their stability, biodegradability, ease of particle size control and no toxicity. In this study, bovine serum albumin (BSA) was functionalized with catechol-containing dopamine (D) to synthesize D-BSA NPs using pH responsive catechol-metal coordination bonds. Instead of using glutaraldehyde, V(III) ion was used as a cross-linker for synthesizing NPs. Catechol-V(III) coordination bonds provided pH responsive NPs due to their different stoichiometry of catechol-metal complexes (e.g. mono-, bis- or tris-) at different pH values. For the synthesis of D-BSA NPs, desolvation method was used with acetone as desolvating agent. Uniformly sized NPs were synthesized with an average of 294 nm with a PDI value of 0.15. Doxorubicin is loaded to NPs with a 15:1 DOX:D-BSA molar ratio. DOX encapsulation efficiency and drug loading capacity of D-BSA NPs were found to be 98% and 10%, respectively. Conversion to bis- and/or mono- catechol-V(III) complexes in acidic medium resulted in degradation of NPs and rapid release of the loaded doxorubicin (DOX). DOX releases reached to 51, 76 and 95% at pH values 7.4, 5.5 and 4.2, respectively at the end of 80 hours. Furthermore, the cytotoxic effects of prepared D-BSA NPs, in comparison to free DOX were studied with MCF-7 cells. Increasing D-BSA concentrations up to 0.2 mg/mL did not affect the cell viability, significantly. But, upon cell (MCF-7) uptake in vitro, DOX-loaded D-BSA NPs and free DOX reduced cell viability by 75% and 20% in 24 hours, respectively.
  • Master Thesis
    Preparation of Drug Loaded Albumin Nanoparticles in Water / Ionic Liquids Microemulsion Systems
    (Izmir Institute of Technology, 2021) Akdoğan, Yaşar; Yıldırım, Barış; Akdoğan, Yaşar; 03.09. Department of Materials Science and Engineering; 01. Izmir Institute of Technology; 03. Faculty of Engineering
    Nanoparticles (NPs) have been used in various applications such as biotechnology, nanomedicine, and drug delivery systems. Many nanoparticle drug delivery systems have been promoted for cancer treatment, and numerous materials have been investigated to use as drug delivery agents to enhance the therapeutic efficiency and safety of anticancer drugs. Albumin is a natural biopolymer and the most abundant protein in blood plasma. Due to its versatile binding capacity of widespread therapeutical drugs, albumin becomes an ideal material to obtain nanoparticles. In this study, the ionic liquid (IL) based emulsification methods were investigated. Instead of classical toxic and volatile solvents, using ILs in microemulsions, environment-friendly media were received to synthesize bovine serum albumin (BSA) NPs. In order to obtain BSA NPs, high-speed homogenizer processing was applied by following crosslinker addition. The IL microemulsions are a thermodynamically stable colloidal dispersion containing spherical droplets (W/IL or IL/W) in submicron sizes that act as nanoreactors for NP formation. Chlorambucil (CHL) was used as a model drug to investigate drug loading and releasing kinetics of BSA NPs as a drug delivery candidate. Results showed that chlorambucil loading capacities and release kinetics depended on the synthesized medium such as anion-type of ILs and surfactants. CHL loaded to the BSA NPs synthesized in hydrophilic IL BmimBF4 in relatively higher amounts and released in the same trend. In addition, the cell viability effect of CHL-loaded BSA NPs synthesized in different types of ILs were investigated. The CHL-loaded BSA NPs synthesized in BmimOTf and BmimPF6 reduced the cancer cell viability more than the used same dose of free CHL.
  • Master Thesis
    Preparation and Characterization of Serum Albumin Nanoparticles Obtained From Modified Bovine Serum Albumin
    (01. Izmir Institute of Technology, 2021) Akdoğan, Yaşar; Demir, Mustafa Muammer; Akdoğan, Yaşar; Demir, Mustafa Muammer; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    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
    Selective Loading of Organofilic Ag Nanoparticles in Ps-Pmma Blends
    (Izmir Institute of Technology, 2014) Tüzüner, Şeyda; Demir, Mustafa Muammer; Ebil, Özgenç; Demir, Mustafa Muammer; Ebil, Özgenç; 03.02. Department of Chemical Engineering; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    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; Demir, Mustafa Muammer; Alsoy Altınkaya, Sacide; Alsoy Altınkaya, Sacide; Demir, Mustafa Muammer; 03.02. Department of Chemical Engineering; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    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
    Tribological Behaviour of Polymer Nanocomposities Containing Tungsten Based Nanoparticles
    (Izmir Institute of Technology, 2007) Karal, Kazım; Tanoğlu, Metin; Tanoğlu, Metin; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The use of nanostructured fillers in epoxy systems has a significant role on the development of thermosetting composites. Recent investigations on inorganic nanoparticles filled polymer composites reveal their significant potential in producing materials with low friction and/or high wear resistance. In the present study, epoxy nanocomposites and fiber reinforced polymer (FRP) composites were prepared with the addition of tungsten based nanostructured particles which are produced by mechanical alloying. The effects of the nanostructured additives on the tribological, mechanical and thermal properties of composite laminates and nanocomposites were investigated. Composite laminates with and without filler were manufactured by using hand lay-up technique and cured under compression. It was found that tungsten based particle loading has no significant effect on the flexural properties of the nanocomposites and the composite laminates, and the tensile properties of the nanocomposites. It was found that while the addition of 3 wt. % of nanoparticles increases the hardness values, it significantly improves the wear resistance of nanocomposites. Furthermore, the significant improvement on the wear resistance was observed with the addition of 3 wt. % W-SiC-C (24h mechanical milling) powder onto the surface of fiber reinforced epoxy. The worn surfaces were examined with scanning electron microscopy (SEM) and the results revealed that wear mechanisms are altered due to the presence of nanoparticles in the matrix. Differential scanning calorimetry (DSC) results showed that nanoparticles have no significant effect on glass transition temperatures (Tg) of nanocomposites. Incorporation of nanoparticles increased the thermo mechanical properties of nanocomposites and composite laminates; including the storage and loss modulus and Tg.
  • Master Thesis
    Investigation of Gas Sensing Properties of Nanoparticles Functionalized With Ferrocene Molecules
    (Izmir Institute of Technology, 2013) Güzelaydın, Abdurrahman Halis; Tarhan, Enver; Tarhan, Enver; Tarhan, Enver; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    In this study, gas sensing properties of ferrocene functionalized multi-wall carbon nanotubes (MWCNT) and iron oxide nanoparticles were investigated via acoustic wave and electrical based techniques. Commercially obtained multi-wall carbon nanotubes having amine functional groups grafted directly onto their surfaces were covalently functionalized with ferrocene molecules. Iron oxide nanoparticles synthesized by the alkaline coprecipitation of ferric and ferrous salts were functionalized with ferrocene molecules. Dispersions of each modified nanoparticle in 3 mL ethanol were prepared and sonicated for 12 h in order to ensure adequate homogeneity. 5 ï ­L from each of these dispersions were then drop-cast onto AT-cut gold coated quartz crystal microbalance (QCM) and gold interdigitated (IDE) glass electrodes with 3 ï ­m interdigit spacing followed by drying on hotplate at 60 °C for 30 min to deposit thin-films. The thin-film coated electrodes were exposed to alternately varying concentration levels of CO, CO2, O2 and humidity ranging from 0 vol% to 100 vol% in predetermined intervals by a computer controlled mass flow meter array in an electromagnetically shielded and hermetically sealed measurement cell specifically designed to acquire QCM and electrical signals from the electrodes. Gas sensor responses of the thin-film coated QCM electrodes were assessed by measuring the frequency shift of the vibrating quartz crystal from its natural resonance frequency and evaluating that value into adsorbed mass according to Sauerbrey relation, whereas, responses from the interdigitated electrodes were assessed by measuring the resistance changes through the thin-film coating under a compliance current value of 1.0000 mA.
  • Master Thesis
    Development of Liquid Armor Materials and Rheological Behavior of Shear Thickening Fluids (stfs)
    (Izmir Institute of Technology, 2011) Erdoğan, Taner; Tanoğlu, Metin; Tanoğlu, Metin; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Colloidal dispersions have been extensively used in many industrial applications such as cosmetic, paint, cement, lubricant and ceramic. Shear thickening is non- Newtonian flow behavior often observed in concentrated colloidal dispersions as an increase in viscosity with increasing shear rate or applied stress. Shear thickening fluids (STFs) exhibit fluid and solid-like properties depending on the shear rate and thus can be used in a variety of applications. In the present study, STFs have been synthesized with various weight fractions of silica nanoparticles in polyethylene glycol (PEG)/ethyl alcohol by mechanical mixing method. The steady and dynamic rheological behavior of shear thickening fluids (STFs) was investigated with rheometer. STFs thermal properties were investigated through thermogravimetric analysis. STFs have been used to improve the performance of Kevlar woven fabrics for protective applications in ballistic and stab. STFs/Kevlar fabric composites have been prepared with different impregnation techniques to evaluate the effects of the STFs. The ballistic performance and stab resistance of STFs impregnated Kevlar fabrics were investigated. Rheological measurements revealed the shear thickening effect of silica nanoparticles/PEG systems depending on the shear rate. In dynamic experiments, the strain thickening behavior was found at critical combination of strain amplitude and frequency. The viscous G modulus values were found to be greater than the elastic G modulus. The elastic G and the viscous G modulus values were found to increase when the strain amplitude is kept constant and frequency is increased. The same strain thickening behavior was also found when the frequency was kept constant and the strain amplitude was increased. The puncture resistance of STFs/Kevlar fabric composites exhibited significant improvements as compared to the neat Kevlar targets. Based on the SEM results, STFs were uniformly impregnated over the entire surface on the Kevlar fabric and Kevlar fabrics completely coated with STFs. The ballistic test results revealed STF/Kevlar fabric composites have potential to obtain liquid armor materials.