Master Degree / Yüksek Lisans Tezleri

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

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Author: search.filters.author.Bulmuş Zareie, Esma VolgaSubject: search.filters.subject.Polymers

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Now showing 1 - 4 of 4
  • Master Thesis
    Sericin-Polymer Conjugates: Preparation and Physicochemical Characterization
    (Izmir Institute of Technology, 2017) Gül, Abdulkadir; Bulmuş Zareie, Volga; Bulmuş Zareie, Esma Volga; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Sericin is a protein derived from silkworm, Bombyx mori, and has several useful properties as a natural biomaterial such as antioxidant character, moisturizing ability, hydrogel forming property and most importantly immunogenic inertness. The aim of this thesis is to prepare and physicochemically characterize sericin-polymer conjugates as potential natural-synthetic hybrid biomaterials with enhanced properties for drug delivery and tissue engineering applications. For this purpose, three polymers having the same degree of polymerization (n~42) and varying chemical nature, i.e. poly(oligoethylene glycol methacrylate), P(OEGMA) hydrophilic and neutral, poly(hydroxyethylmethacrylate) P(HEMA) less hydrophilic and neutral, and poly(dimethylaminoethyl methacrylate) P(DMAEMA) hydrophilic and cationic after quaternization, were first synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization. Each polymer was characterized via nuclear magnetic resonance (1H-NMR) and gel permeation chromatography (GPC). Separately, molecular weight and isoelectric point of sericin were characterized using various techniques including Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and High-Resolution Two-Dimensional Polyacrylamide Gel Electrophoresis (2D-PAGE). Polymers were then covalently conjugated to sericin using NHS/EDC chemistry. The conjugates were characterized using SDS-PAGE, GPC and DLS (Dynamic Light Scattering). The SDS-PAGE and GPC results showed the successful preparation of the conjugates. DLS revealed that the hydrodynamic size of P(OEGMA) and P(DMAEMA) polymers and their conjugates were between 1 and 10 nm as they are soluble in PBS and do not form aggregates. Unlike the other two polymers, although the size of P(HEMA) polymer was observed to be 3.24 ± 0.62 nm, the DLS measurements of P(HEMA) conjugates indicated the presence of self-organization and aggregation of Sericin-P(HEMA) conjugates in aqeuous solution. Consequently, the size of sericin-P(HEMA) conjugates were found to be 530 ± 60.83 and 223.3 ± 25.2, respectively.
  • Master Thesis
    Development of Arginine-Containing Well-Defined Polymers
    (Izmir Institute of Technology, 2014) Taykoz, Damla; Bulmuş Zareie, Volga; Bulmuş Zareie, Esma Volga; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The aim of this work is to synthesize arginine-containing well-defined polymers via reversible addition-fragmentation chain transfer (RAFT) polymerization and perform preliminary investigation on the use of these polymers in nucleic acid complexation for potential gene therapy applications. Pentafluorophenyl methacrylate (PFMA) was chosen as an active ester monomer to produce polymers having functional groups available for further modification. RAFT polymerization of PFMA was performed varying polymerization conditions such as feed composition and polymerization temperature. Polymers (PPFMA) were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography. Linear increase in ln[M]0/[M] with polymerization time, and number average molecular weight (Mn) with monomer conversion indicated RAFT controlled polymerization of PFMA under the conditions tested. Furthermore, block copolymers of PFMA with poly(ethylene glycol) methacrylate (PEGMA) as a biocompatible component were prepared. Copolymerization was studied using both P(PFMA) and P(PEGMA) as macro RAFT agent. Copolymerization kinetic studies indicated that chain extension block copolymerizations were successfully performed using both macroRAFT agents. P(PFMA) was reacted with arginine methylester (AME) in the presence of triethylamine (TEA). 100% of P(PFMA) active ester groups could be modified with AME at a polymer/AME/TEA mole ratio of 1/1/3, as determined by 1H-NMR spectroscopy. The AME modified polymers were complexed with a 681-bp DNA fragment through electrostatic interactions at varying nitrogen/phosphate (N/P) ratios. Gel electrophoresis experiments revealed that AME-modified P(PFMA) was able to complex with DNA at a N/P ratio of 200. Furthermore, the hydrodynamic diameter (Dh) of polymer/DNA complexes in phosphate buffer saline was found to be 58 nm, while the free DNA displayed a Dh of 109 nm, indicating the complexation of DNA by AME-modified P(PFMA).
  • Master Thesis
    Synthesis of Amine Containing Well-Defined Polymers Via Reversible Addition-Fragmentation Chain Transfer (raft) Polymerization and Their Characterization
    (Izmir Institute of Technology, 2013) Kurtuluş, Işıl; Bulmuş Zareie, Volga; Bulmuş Zareie, Esma Volga; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The aim of the study is to synthesize well-defined, spermine-like, amine containing polymers via reversible addition fragmentation chain transfer (RAFT) polymerization as a potential endosomal escaping agent for intracellular drug delivery applications. Tert-butyl (2-((tert-butoxycarbonyl) amino) ethyl)(2-hydroxyethyl)carbamate was first synthesized and then methacrylated to yield 2-((tert-butoxycarbonyl) (2- ((tert-butoxycarbonyl) amino) ethyl) amino) ethyl methacrylate, (BocAEAEMA). BocAEAEMA was then polymerized via RAFT polymerization. A series of RAFT polymerization kinetics experiments were performed in order to investigate the RAFTcontrolled character of polymerizations. The effect of [M]/[R] ratio at constant monomer (0.36 M, 0.72 M and 1.44 M) and initiator concentrations (3.6x10-3 M) on polymerization kinetics was first investigated. Linear proportionality between ln [M]0/[M] and polymerization time, and Mn and conversion, indicated the RAFTcontrolled polymerization of BocAEAEMA monomer under the conditions tested. Boc-AEAEMA polymers were deprotected to yield AEAEMA polymers prior to assays performed to determine cytotoxicity and proton sponge capacity of polymers. Proton sponge capacity of AEAEMA polymers (5.5 kDa and 8 kDa) and PEI (25 kDa and 60 kDa) was investigated via potentiometric titration using constant polymer (2.2 x10-5 M) or repeating unit (2.9 x10-5 M) concentrations. The proton sponge capacity of p(AEAEMA)was found to be comparable to those of PEIs at the same repeating unit concentration. AEAEMA polymers did not show cytotoxic effect on NIH 3T3 cells up to 1.6 M concentration, tested via a cell viability assay for 24h and 72 h.
  • Master Thesis
    Development of End-Group Functional Temperature-Responsive Polymers
    (Izmir Institute of Technology, 2013) Özer, Ekrem; Bulmuş Zareie, Volga; Bulmuş Zareie, Esma Volga; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The aim of this thesis was to synthesize temperature-responsive, well-defined, end-group modified (co)polymers of oligoethyleneglycol methyl ether methacrylate (OEGMA300) and diethyleneglycol methyl ether methacrylate (MEO2MA) via reversible addition fragmentation chain transfer (RAFT) polymerization, and to investigate in detail the temperature-responsive behaviour of the resultant (co)polymers considering the possible use of these (co)polymers in temperature-controlled biosensing applications. A series of (co)polymerization kinetic experiments were performed at three different [Total monomer]/[RAFT agent] molar ratios and yielded copolymers of OEGMA300 and MEO2MA with controlled molecular weights and low polydispersities (<1.2), indicating RAFT-controlled (co)polymerization mechanism. The reactivity ratios of the comonomers, MEO2MA and OEGMA300, determined using Kelen-Tüdŏs method were 0.96 and 0.98, respectively. This indicated that the copolymers were truly random and their composition could be controlled by the feed comonomer composition. A number of (co)polymers having varying molecular weights, compositions and end-group functionalities (i.e. thiocarbonylthio RAFT end-group, pyridyldisulfide (PDS) or phosphonate group) were synthesized to investigate the effects of these parameters on the Lower Critical Solution Temperature (LCST) of the (co)polymers. The end-group functionality, PDS or phosphonate, was chosen considering the possible use of these polymers on gold or alumina surfaces, respectively. The key factor affecting the LCST was found to be the hydrophilic/hydrophobic balance of the (co)polymers. Increasing the hydrophilic content (OEGMA content) of the (co)polymers increased the LCST values. The effect of end-group on the LCST was more profound for (co)polymers with low molecular weights. Replacement of the thiocarbonylthio end-group with a more hydrophilic group such as PDS or phosphonate resulted in a significant increase in the LCST of the copolymers having a degree of polymerization of less than 30. For the copolymers with higher degree of polymerization, the influence of the end-group chemistry on the LCST became negligible.