Master Degree / Yüksek Lisans Tezleri

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

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2014 - 20193

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

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Now showing 1 - 3 of 3
  • Master Thesis
    Evaluation of Biophysical Aspedts of Cancer Using Lab-On Chip Devices
    (Izmir Institute of Technology, 2019) Tahmaz, İsmail; Pesen Okvur, Devrim; Sürmeli, Nur Başak
    Breast cancer metastasis is really crucial point from cancer related deaths. As cancer cells from primary tumor are travelling through blood, they hang on to blood vessel and finally they exit from blood vessel into secondary site where is extracellular matrix and/or tissue/organ. This process commonly known as extravasation. Cancer cells sometimes can be highly aggressive when it exposed to hypoxia referred low oxygen amount by activating HIF1α. This transcription factor is activated in malignant cells, normal cells and endothelial cells in blood vessel when oxygen amount decreased to certain levels and it induce several genes expression such as VEGF, LOX, Angiopoietin-like-4 etc. In this study we investigated effect of HIF1α which is hypoxia indicator on breast cancer extravasation by comparing to normal oxygen level. This study represents both anemic hypoxia physiologically and lead to understand underlying mechanism of extravasation into extracellular matrix related to low oxygen circulating through blood. In addition to HIF1α effects, dynamic perfusion mimicking blood flow was applied to determine effects on extravasation. For this purpose, lab-on-a chip device was utilized for real time visualization. In conclusion, although hypoxia is giving permission MDAMB231 to extravasate because of reshaping of vascular geometry, less extravasated cancer cells observed in matrix during hypoxia under both static and flow condition when compared to normoxic and static conditions. Moreover, it was shown that flow triggers extravasation distance in normoxia against static condition and normal breast epithelial cells extravasated away in hypoxia comparing breast cancer cells by means of flow.
  • Master Thesis
    Design and Fabrication of Microfluidic Device That Allows Investigation of Distance Dependent Interactions of Two Different Cell Types
    (Izmir Institute of Technology, 2014) Sağlam, Murat; Pesen Okvur, Devrim; Özyüzer, Lütfi
    The main studies of in this thesis, the mold and a microfluidic device are achieved by using SU-8 photoresist and PDMS polymer. Firstly, molds are obtained which are thickness ranging from 30 to 400 μm by using SU-8 photoresist with UV lithography technique and this molding will use for shaping polydimethylsiloxane (PDMS) polymer. Finally, PDMS molds combined with the glass surface to create a three dimensional reservoirs. Microfluidic device that allows investigation of distance dependent interactions, two factors are positioned at certain distances from each other and the microfluidic device is allowed to investigation of distance dependent interaction of two factors. There is an alternating width channel between two channels which have each of two factors. These three channels are separated from each other by colonnades, not by walls, therefore physical, chemical and biological interactions are possible between the factors. Necessary physical, chemical, and biological conditioning can be provided by the reservoirs which are neighbor of channels including factors. Microfluidic chip has a lot of advantages that are small liquid volumes (pL-μL), precise spatial & temporal control, successfully mimic the physiological context, highthroughput analysis, low fabrication costs; portable and safer therefore it facilitates us to refine our methods of analysis and development in cell biology investigations and determining the content of chemical samples.
  • Master Thesis
    Method That Positions Cell-Laden or Cell-Free Matrices at Defined Positions From Each Other Inside a Single Microfluidic Channel
    (Izmir Institute of Technology, 2014) Tarım, Emre; Pesen Okvur, Devrim; Özyüzer, Lütfi
    In recent years, the use of microfluidic has increased in the field of many biological studies. Microfluidic technology has a large area which is a joint product of biology and industry covering all branches of science. The small size of the microfluidic chip offers many advantages in the use of microfluidic. During the analysis, the microfluidic chip offers many advantages such as, use of less material, less waste generation, temporal control, opportunity of analysis under the microscope and high throughput analysis. In addition to these, while microfluidic chip is providing a safe environment for users, via mimicking the physiological environment, it also provides a suitable environment in order to make cell, tissue and organs based assays. Microfluidic devices especially use in cancer studies, chemical analysis, tissue engineering, drug screening, immunology and stem cell differentiation. In this study, we aimed to develop methods depending on the distance to position the MDA-MB 231 breast cancer cells in the microfluidic channels. Firstly, the microfluidic channels were obtained by using the soft lithography and experiments with breast cancer cells were performed using these channels. Breast cancer cells containing matrix was loaded into microfluidic chips and precipitated onto blank matrix by using centrifuge. The aim of repeating this process was to position the breast cancer cells at different distanced locations.