Phd Degree / Doktora

Permanent URI for this collectionhttps://hdl.handle.net/11147/2869

Browse

Filters

2009 - 200912010 - 20191

Settings

Publisher: search.filters.publisher.Izmir Institute of TechnologySubject: search.filters.subject.Nanotechnology

Search Results

Now showing 1 - 2 of 2
  • Doctoral Thesis
    Development of Plasmonic Nanostructures for Photothermal Therapy of Prostate and Breast Cancer
    (Izmir Institute of Technology, 2019) Tomak, Aysel; Bulmuş, Volga; Şahin, Hasan
    The aim of this thesis is to synthesize gold nanorods (AuNRs) and lipid-stabilized nanobubbles containing AuNRs and investigate the potential of these plasmonic nanostructures as photothermal therapy agents for breast and prostate cancer through in vitro cell culture experiments. For this aim, firstly, AuNRs were synthesized at varying aspect ratios (ARs) and characterized via several techniques including UV-Vis/NIR spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), inductively coupled plasma-mass spectroscopy (ICP-MS), electrophoretic light scattering (ELS) and X-ray photoelectron spectroscopy (XPS). The surface of AuNRs was modified with a biocompatible polymer, poly(ethylene glycol) (PEG), via ligand exchange method. Cytotoxicity, cell uptake and photothermal effects of AuNRs were investigated via in vitro cell culture experiments using human prostate cancer (DU 145) and epithelial (RWPE-1), breast cancer (MCF7) and epithelial (MCF 10A) cell lines. It was concluded that AuNRs (AR=4.0) were superior than AuNRs (AR=7.0) in terms of cell viability and photothermal effect. Separately, a non-commercial antibody (Ab) targeting a specific sialic acid derivative on the plasma membrane of DU 145 and MCF7 cancer cells was conjugated to AuNRs. Conjugations were characterized with the same techniques and investigated via in vitro cytotoxicity and cell uptake experiments. The Ab-conjugated AuNRs displayed the capability of selective targeting prostate cancer cells. Additionally, lipid-stabilized AuNRs and lipid-stabilized nanobubbles containing AuNRs (AuNBs) were synthesized for the first time and characterized using UV-Vis/NIR spectroscopy, SEM, ICP-MS and ELS techniques. Lipid-stabilized AuNRs were successfully synthesized using varying lipid mixtures instead of cationic, toxic surfactant. Separately, AuNBs were synthesized by combining PEG modified AuNRs with DPPC: DSPE-PEG lipid film under sonication and gas stream. AuNBs showed the same or significantly lower toxicity depending on the cell types and the same photothermal effect with respect to AuNRs (AR=4.0) upon irradiation under laser at 808 nm.
  • Doctoral Thesis
    Nanosized zing borate production
    (Izmir Institute of Technology, 2009) Gönen, Mehmet; Balköse, Devrim
    The present study covers both zinc borate synthesis from boric acid-zinc oxide and borax decahydrate-zinc nitrate hexahydrate pairs; treatment of those samples by supercritical carbon dioxide drying, supercritical ethanol drying, and freeze drying techniques to obtain nanosized products. Zinc borate samples before and after supercritical drying were characterized by analytical titration, SEM, XRD, TGA, DSC, FTIR, and N2 adsorption at 77 K.The use of oleic acid as a modifying agent, ultrasonic treatment and nanosized zinc oxide in the reaction of zinc oxide and boric acid did not make significant effect in controlling the particle size. However, particle size of zinc borate produced from borax and zinc nitrate has increased with reaction time. Interaction of zinc borates with CO2 or ethanol at supercritical conditions or compression of crystals by high pressure created by the expansion of water during freezing are possible side effects of the nanoparticle producing processes. Zinc borate (2ZnO.3B2O3.7H2O) having water of crystallization in its structure reacted partially with CO2 to produce zinc carbonate, however zinc borate (2ZnO.3B2O3.3H2O) containing only hydroxyl groups did not react with CO2 in supercritical CO2 drying. While zinc borate (2ZnO.3B2O3.3H2O) decomposed partially and formed anhydrous zinc borate and zinc oxide, zinc borate (ZnO.B2O3.2H2O) decomposed completely and formed only zinc oxide in the supercritical ethanol drying that was carried out at 6.5 MPa and 250aC. Boric acid formed from the decomposition of both zinc borates was separated by ethanol extraction. If the initial particle size of zinc borate sample was at nano level, it would be possible to obtain nano particles by freeze drying.