Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/5799
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Master Thesis Centella asiatica extract containing bilayered electrospun wound dressing(Abdullah Gül Üniversitesi, 2019) KOÇ, NURAY; İşoğlu, İsmail AlperInnovative and bioactive wound dressings prepared by electrospinning mimicking the native structure of the extracellular matrix (ECM) have gained significant interest as an alternative to conventional wound care applications. In this study, bilayered wound dressing material was produced by sequential electrospinning of quaternized poly(4- vinyl pyridine) (upper layer) on the Centella Asiatica (CA) extract containing electrospun poly(D, L-lactide-co-glycolide) (PLGA)/poly(3-hydroxybutyrate-co-3- hydroxy valerate) (PHBV) blend membrane (lower layer). Scanning electron microscopy (SEM) was utilized to show a uniform and bead-free fiber structure of electrospun membranes. The average diameter of CA extract containing electrospun PLGA/PHBV blend membrane was calculated 0.471±0.11 µm, whereas the average fiber diameter of electrospun poly(Q-VP) membranes was in the range of 0.460±0.057 µm. Chemical, thermal, mechanical properties, and adsorption capacity of electrospun membranes, as well as the cumulative release of CA from the electrospun PLGA/PHBV membrane, were investigated. Viability, adhesion, and attachment of human fibroblast cells on the electrospun membranes on pre-set days were evaluated by the colorimetric CellTiter 96® Aqueous One Solution Cell Proliferation Assay (MTS assay) and SEM. Results revealed that CA loaded bilayered electrospun wound dressing showed promoted attachment and proliferation of fibroblasts. Hence, it can be concluded that CA extract containing bilayered electrospun wound dressing prepared in this study has a promising potential for wound healing applications.Master Thesis Potansiyel Gen Dağıtımı Uygulamaları için Poegma ve Sistaminle Modifiye Plazmit DNA'lar İçeren Polimerik Konjugatlar(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2024) Yıldız, Gizem; İşoğlu, İsmail Alper; İşoğlu, Sevil DinçerPolymer-based gene delivery systems have revealed significant advancements in the treatment of various diseases in recent years. Considering the potential of polymeric vectors, it is observed that the improvements in the field of gene therapy enable effective gene transfection and induced therapeutic protein production. In this thesis study, a strategy based on a new conjugation procedure is designed to increase the gene transfer and cellular uptake rate of plasmid DNAs. According to the findings, POEGMA-based carrier and cystamine-modified plasmid DNAs demonstrated successful conjugation through disulfide bond formation. MDA-MB-231 in vitro cellular uptake results of conjugates showed 94-98% cell internalization, indicating excellent results compared to the well-known polymers in the literature. As a result, the new delivery system we developed in this study determined the success of cystamine-modified plasmid DNAs binding to POEGMA polymer chains via a covalent linkage for the first time in the literature and provided a start for future studies.Master Thesis 3D Biyobaskı Parametrelerinin PCL İskelesinin Basılabilirliği ve Mekanik Davranışı Üzerindeki Etkisi(Abdullah Gül Üniversitesi / Fen Bilimleri Enstitüsü, 2023) Ceylan, Saniye Aylin; İşoğlu, İsmail AlperPolycaprolactone (PCL) is a synthetic polymer that exhibits desirable properties such as biodegradability, tolerable mechanical properties, and biocompatibility for a diverse range of tissue engineering applications. In this study, we analyzed the effects of polymer concentration (10%, 25%, 50% and 75% w/v), solvent effect (dichloromethane, chloroform and acetic acid), and device parameters (pressure, speed, nozzle-surface distance, nozzle gauge, infill density) on printed scaffolds fabricated through 3D Bioprinting. Scanning electron microscopy (SEM) and optical microscopy were used to assess printability, and uniaxial tensile testing was performed to evaluate mechanical behavior. The aim of this study was to investigate the effects of different printing speeds (5 mm/s, 10 mm/s, and 15 mm/s) on the mechanical properties of PCL_DCM and PCL_CF scaffolds. The scaffolds printed at the lowest speed exhibited the highest ultimate tensile strength (UTS) values. Scaffolds printed at 5 mm/s with the highest printing pressure (480 kPa) demonstrated a remarkably high Young's modulus of 39.69 MPa and a UTS value of 6.4 for PCL_DCM, as well as Young's modulus of 26.80 MPa and a UTS value of 6.3 MPa for PCL_CF. Additionally, we investigated the influence of polymer concentrations (50% and 75%) and infill densities (50%, 70%, and 90%). The results showed that increasing the infill density and using a lower concentration (50%) led to improvements in Young's modulus and UTS values for both PCL_DCM and PCL_CF scaffolds. These results highlight the importance of carefully controlling printing parameters to optimize the mechanical properties of the printed scaffolds.