Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
Browse
9 results
Search Results
Master Thesis Development of Doxorubicin-Loaded Liposomes Self-Assembled With Polysaccharides for Breast Cancer Therapy(01. Izmir Institute of Technology, 2023) Önol, Ayşenur Başar; Kılıç Özdemir, Sevgi; Polat, HürriyetThis thesis aimed to develop Tariquidar and Doxorubicin-loaded liposomes decorated by Fucoidan coating for breast cancer treatment. Fucoidan is a negatively charged polysaccharide with a special affinity to p-selectins expressed on MDA-MB-231 breast cancer cells and, at the same time, possesses anti-cancer activity. Different liposomes were prepared by extrusion method from the DSPC, Cholesterol, and cationic lipid DSTAP mixtures for coating negatively charged Fucoidan. The most stable liposomes with a size of 200 nm were obtained at a molar ratio of DSPC/Cholesterol/DSTAP:55/30/15, exhibiting a zeta potential above +30 mV. Tariquidar was encapsulated into the liposome bilayer by passive loading, and Doxorubicin into the core of the liposome by active loading. In the final step, liposomes were coated with Fucoidan by electrostatic interaction. Tariquidar loading was determined by UV-Vis spectrophotometry, indicating an optimum TRQ/Lipid molar ratio of 0.012 with encapsulation and loading efficiencies of 50% and 20%, respectively. Fluorescence spectrophotometry determined Doxorubicin loading, showing insignificant encapsulation efficiency change (exhibiting around 70%) by neither Tariquidar content in the bilayer nor DSTAP% in the formulation. An optimum amount of Fucoidan was determined by incubating the liposomes with varying amounts of fucoidan at different dilutions. Size and zeta potential measurements monitored the coating of liposomes with Fucoidan. Our finding showed that zeta potentials of liposomes go from positive to negative with increasing fucoidan, while no trend was observed in the size of liposomes. However, smaller sizes were observed when incubation was performed in diluted solutions.Master Thesis Enhancement of Bioavailability of Vitamin D by Nano-Sized Delivery Systems(01. Izmir Institute of Technology, 2023) Sağlam, Ezgi İrem; Kılıç Özdemir, Sevgi; Bulmuş Zareie, Esma VolgaStudies have indicated that Vitamin D (VitD) may decrease tumor invasiveness and propensity to metastasize. Cholecalciferol (VitD3) is the passive form of VitD3 and converts to active calcitriol through two-step hydroxylation reactions in the body, promoting binding to VitD-receptors (VDR). However, some breast cancer cells, especially MDA-MB-231, have very low levels of VDR. Besides, VitD3 suffers from first pass-effect of the liver which causes deactivation of VitD3. Therefore, new approaches are needed to increase VitD3 level in the cancerous sites. In this study, VitD3 was loaded into liposomes, which were subsequently coated by Fucoidan (FUC) to promote their binding to MDA-MB-231 cancer cells. Fucoidan strongly binds to P-selectins overexpressed in the breast cancer cells, blocking the cancer cells to adhere on the platelets to carry within the body, causing metastasis. Doxorubicin (DOX), being considered as the one of the most effective chemotherapeutic agents against breast cancer, was also loaded into liposomes in a similar manner. By liposomal encapsulations and fucoidan coating, it was aimed to deliver the all-cargo directly to the cancerous site and enhance the bioavailability of both agents at the target site. It was seen that liposomal VitD3 was more effective than free form to inhibit cell proliferation and, therapeutic potential of DOX increased with VitD3.VitD3 loaded FUC coated liposomes at optimized concentrations has a comparable effect with DOX-loaded liposomes with and without FUC coating. Overall, these results suggested that VitD3 and DOX loaded and FUC coated liposomes can be applied as combined therapy in cancer treatment.Master Thesis Determination of Therapeutic Effects of Multifunctional Antibody and Peptide Micelle-Based Nanocarriers on Breast Cancer Cells(01. Izmir Institute of Technology, 2021) Abdulhadi, Nusaibah Abdulsalam Abdulhad; Baran, YusufBreast cancer is the most prevalent type of cancer and a major cause of death among women globally. Currently, many treatments are developed to reduce breast cancer death risks. Targeting therapy represents an advanced and successful approach. It provides targeting specific tumor sites by using specific ligands and modifying physicochemical characterization of nanocarriers to increase drug efficiency. In this study, we aim to determine and compare the therapeutic effects of doxorubicin (DOX)- loaded nanocarrier that was synthesized by using two properties a core cross-linked and pH sensitivity to increase drug stability and DOX releasing at the tumor site. The effects of DOX-loaded micelles (DM), HER2 targeting peptide (LTVSPWY)-conjugated-DOX-loaded micelles (DMP), and antibody (Herceptin) conjugated-DOX-loaded-micelles (DMA) on HER2 positive SKBR-3 cell line and HER2 negative MCF-10A normal epithelial breast cell line were determined by using cytotoxic, apoptotic, cytostatic, and genotoxic assays. According to the cytotoxic assay, the IC50 value of DM, DMA, and DMP were 0.71-, 0.49-, 0.34-µM, respectively. Additionally, the fluorescence image showed higher DOX uptake by SKBR-3 cells treated with DMP. According to the apoptotic assays, the mitochondrial membrane potential on SKBR-3 cells with treated DMP decreased as well as higher apoptosis and necrosis rate that was regulated by Bcl-2, Pro-Caspase-3, PARP1, Bax, Bak, and Bcl-xL. Besides, the application of DMP caused cell cycle arrest at the G2/M phase. Lastly, DNA damage was observed in response to DMP determined by comet assay. This study provides a novel and effective therapeutic option for breast cancer through using this nanocarrier system with targeting properties.Master Thesis Development of Ultrasound Triggered Drug Delivery Systems for Cancer Treatment(Izmir Institute of Technology, 2019) Önercan, Cansu; Kılıç Özdemir, SevgiDoxorubicin (DOX) is one of the most commonly used hydrophilic anticancer drug in cancer treatment. However, when it is used in free form, it can attack not only cancer cells but also healthy cells. So as to prevent entering of DOX to the healthy cells, the encapsulation method is employed. Liposomes are suitable for encapsulation of DOX but the most important problems with the use of liposome are hand-foot syndrome and stomatitis. Encapsulation method is not enough because of these reasons, thus delivery of DOX to the desired site by targeted therapy has gained interest in recent years. In this study, DOX was encapsulated into liposomes and the DOX loaded liposomes (LipoDOX) was attached to microbubbles (MBs). MBs as ultrasound contrast agents are widely used in medical imaging. Use of MBs in combination of DOX loaded liposomes facilitates the uptake of the drug because ultrasound cavitation results in opening of transient pores in cell membrane via a process named sonoporation. Herein, MB-LipoDOX complex was engineered to optimize the size of the complex as well as the loaded DOX content. For this purpose, determination of incubation temperature and time for DOX loading into liposome and optimization of liposome formulation for maximum DOX loading were studied. Ratios of Lipid/Cholesterol/PEGylated lipid, PEG chain length and PEG molar ratio in liposome were determined. Also, determination of Strept Avidin (StAv) to Biotin ratio in LipoDOX and the amount of LipoDOX in LipoDOX-MB complex were studied. For characterization, Dynamic Light Scattering (DLS) method, Fluorescence Spectrometry method and Coulter Counter device were used. Lipoosme size was found to be associated with the pore size of polycarbonate membrane (200nm) resulting in liposomes at around 190±5 nm in size . When the PEGylated lipid with PEG chain of 2000 was used in liposome structure, particle size distribution is more monodispersed than the others. The maximum amount of DOX loaded liposomes was obtained at 32% Cholesterol, 5% DSPE-PEG2000, after 90 min. incubation at 65oC incubation. Optimum StAv to Biotin ratio in LipoDOX was determined as 1.0. The optimum molar ratio of Biotinylated lipids in LipoDOX was determined as 0.05% and the optimum molar ratio of Biotinylated lipids in MBs was determined as 8%.Master Thesis Determination of Therapeutic Effects of Multifunctional Micelle-Based Nanocarriers on Breast Cancer Cells(Izmir Institute of Technology, 2019) Ulu, Gizem Tuğçe; Baran, YusufBreast cancer is the most common and frequent cause of death among women composed to all types of cancer. Current treatment protocols do not provide complete cure or selective drug delivery while targeted therapy can provide an important avenue for successful treatment of breast cancer. In this study, therapeutic effects of drug-conjugated nanocarrier system with enhanced stability and double moiety pH-sensitivity on breast cancer (SKBR-3- HER-2- positive), normal breast epithelial (MCF-10A, HER-2-negative) and chronic myeloid leukemia (K562, HER-2-negative) cells were determined. With this approach, SKBR-3 cells were targeted by single nanocarriers having selectivity with unused peptide ligand (HER-2), stability with cross-linking of core moiety, and cleavage by two sites of pHeffect and drug release properties. After physicochemical characterization of micellebased nanocarriers, cytotoxic, apoptotic and cytostatic effects of doxorubicin conjugated micelles were determined. Doxorubicin conjugated micelles with HER-2 peptide (DOX-HER-2-NCs) had more cytotoxic effects on HER-2 positive cells. Additionally, intracellular amounts of doxorubicin is higher in SKBR-3 cells with applied DOX-HER-2-NCs as determined by fluorescence imaging. The apoptosis rate was increased on SKBR-3 at 50% cell growth inhibition (IC50) as determined by Annexin-V/Propidium iodide double staining. However, there was not any significant change in loss of mitochondrial membrane potential. Additionally, DOX-HER-2-NCs resulted in cell cycle arrest at G2/M-phase in response to IC50 value. Besides, protein level of Bcl-2 did not change while protein level of Bax and Caspase-3 were increased as determined by Western Blotting. This project provides novel and more effective treatment of breast cancer by using multifunctional properties of nanocarriers.Master Thesis Development of Endosome Disruptive Peptide and Peg Conjugate Based Doxorubicin Delivery System(Izmir Institute of Technology, 2019) Özkıyıcı, Selin; Top, AybenIn this study, it was aimed to develop a drug carrier system including a TAT-derived cell penetrating peptide in order to provide fast transport of anticancer drugs from endosomal compartments to nucleus. The drug delivery system, denoted as mPEGpeptide- oxime-DOX, was based on polyethylene glycol, endosome disruptive peptide (G2RQR3QR3G2S), and doxorubicin (DOX) conjugate. Control drug delivery system, lack of the peptide (mPEG-oxime-DOX) was also synthesized to assess the effect of the peptide on the physiochemical and drug release properties of the drug carrier. As the first synthesis step, mPEG-OH was converted to mPEG-aldehyde form using DMSO-acetic anhydride oxidation reaction and aldehyde functionalization was determined by using FTIR and NMR spectroscopy. The peptide and mPEG-peptide were synthesized using solid phase synthesis protocol, and their purities were confirmed using HPLC and MALDI-TOF mass spectroscopy analyses. Prior to DOX conjugation, hydroxyl group of serine residue in the mPEG-peptide system was oxidized to aldehyde. The anticancer drug was attached to the carrier molecules via amine-aldehyde reaction forming an acid cleavable oxime bond. Drug release, size distribution, and stability of the PEG-peptideoxime- DOX system were evaluated and compared with those results of the control drug delivery system. For mPEG-oxime-DOX, a pH programmed DOX release with the respective % DOX release values of ~68 % and ~28 % at pH 5.0 and pH 7.4 was observed. For mPEG-peptide-oxime-DOX, on the other hand, quite low DOX release (~10-15 %) was obtained for both pH values suggesting possible interaction between DOX and the peptide. Mean size value of the mPEG-oxime-DOX was measured as ~24 nm. However, mPEG-peptide-oxime-DOX, had quite lower hydrodynamic diameter values (~3nm and ~6 nm at pH 5.0 and pH 7.4, respectively) possibly due to repulsions between the arginines in the peptide domain. Observation of the morphology and evaluation of the cytotoxicity of these drug delivery systems are underway.Master Thesis Development of Drug-Loaded Microbubbles for In-Vitro Applications in Cell Biology(Izmir Institute of Technology, 2017) Coşkun, Sema; Özdemir, Ekrem; Sultan Altun, ZekiyeDoxorubicin (DOX) is one of the drugs for cancer therapy. When DOX is used in solution, it affects not only the cancer cells but also the healthy cells. In order to eliminate possible side effects, DOX was encapsulated within liposomes and applied for the cancer therapy. Because the circulation time for liposomes is longer in the body, they accumulate in capillaries, especially at the finger tips and at the toe of the foot called the hand-and-foot syndrome. Here, we proposed to couple the liposomes containing DOX with the microbubbles as the ultrasound contrast agent and deliver the drug to the area of interest. Therefore, DOX was loaded within the liposomes and characterized for their DOX contents. The DOX containing liposomes were conjugated with microbubbles through the avidin-biotin chemistry. It was found that the loaded- DOX content within the liposomes was Langmuir-type. The loaded DOX content increased at lower DOX concentrations and leveled off at higher DOX concentrations. The Langmuir constants can be used in designing DOX loading experiments. The DOX containing liposomes were coupled with the microbubbles and found an optimum of 7.0 for the avidin/biotin mole ratio on the microbubbles. At the optimum avidin/biotin ratio, the conjugated lipo-DOX amount was 3×10-8 μg-DOX/MB. It was concluded that the DOX molecules can be loaded within the liposomes and easily conjugated with the microbubbles and employed in cancer treatments.Master Thesis Comparison Od Side Effects of Anti-Cancer Drugs in 2d and 3d And, Classical and Cell-On Cultures(Izmir Institute of Technology, 2016) Kankale, Deniz; Pesen Okvur, Devrim; Çağır, AliThe studies that aim to assess the effects of drugs developed against cancer at the cellular level use multiwell plates. However, these classical systems fail to reproduce the in-vivo like microenvironment necessary for realistic assessment. In addition, classical cell culture systems use high amount of materials increasing cost. On the other hand, lab-on-a-chip systems use minimal volumes of reagents and more importantly can mimic the in-vivo microenvironment via spatial and temporal control. Furthermore, it is known that cell response to drugs can be very different in 2D and 3D cell culture setups. Doxorubicin is a widely used anticancer drug. Here, doxorubicin uptake by highly metastatic human breast cancer cell line MDA-MB-231 and normal mammary epithelial cell line MCF10A were investigated using 2D and 3D, classical and cell-on-a-chip cultures. Drug uptake at 24, 48 and 72 hours various concentrations of the drug determined by measuring signal intensities from fluorescence microscopy images of cells. For cell viability assay, cells were stained with dapi and two cell lines were compared in systems. According to results, it was observed that 3D cell culture environment in chip provides more in-vivo like environment with less reagent consumption and cell viability is not correlated only with drug uptake.Master Thesis The Effect of Doxorubicin-Albumin Magnetic Nanoparticles on Prostate and Lung Cancer Cells(Izmir Institute of Technology, 2012) Zeybek, Ayça; Şanlı Mohamed, GülşahChemotherapy is a major therapeutic approach for treatment of a wide range of cancers. But unfortunately, this therapeutic approach has got a lot of side effects on healthy tissues as well as cancerous cells. Although doxorubicin is one of the most potent and widely used anticancer drugs, it has some side effects on healthy tissues, as well. Therefore, most researchers have studied various doxorubicin carrier systems for targeted delivery. For this purpose, doxorubicin loaded magnetic albumin nanospheres (M-DOX-BSA-NPs) were synthesized. The main objective of this project was basically to determine the cytotoxic, apoptotic and cell cycle effects of BSA-NPs, M-BSA-NPs, DOX, BSA-DOX-NPs and M-DOX-BSA-NPs against prostate and lung cancer cells and compare them. Beside this, it is aimed to understand how cells look like before and after giving doxorubicin and M-DOX-BSA-NPs by using optical microscopy and compare them. Another objective of this project was to determine where M-DOX-BSA-NPs reach out into the cell by using concofal microscopy; and to explore proteins’ differentiations between control groups and lung and prostate cancer cells in which DOX and M-DOX-BSA-NPs were applied, by proteomic studies. In this study, the experimental results which were also supported by literature findings, demonstrated that M-DOX-BSA-NPs were more toxic than free doxorubicin, and this complex was more effective for prostate cancer cells than lung cancer cells. As a result of this study, it was determined that this complex was synthesized as a target chemotherapy drug delivery system. Accordingly, this complex may affect to other cancer types, and it can be carried out by new drug designers and treatments.