Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Increasing Doxorubicin (dox) Release From Liposomes(Izmir Institute of Technology, 2019) Hanoğlu, Berçem Dilan; Özdemir, Ekrem; Altun, Zekiye SultanCancer is the second most common cause of death in the world and its incidence is increasing day by day. Doxorubicin (DOX) is an anthracycline group drug frequently used in many cancer treatments including breast cancer. However, free DOX has many harmful side effects and need to be encapsulated into nanocarrier such as liposomes. Although liposomal DOX has many advantages over its free form, liposomal DOX has undesirable side effects such as hand and foot syndrome. In this thesis, it was aimed to develop a more effective liposomal DOX delivery and release systems. Liposomes were prepared with alkaline solutions containing tris, sodium carbonate, ammonium chloride, and ammonium sulfate. DOX loading into liposomes and the percentage of release from liposomes were examined. A loading efficiency of about 80% was achieved, while the release was found to be below 13% at room temperature. The release of DOX was found to be enhanced from liposomes in the presence of ammonia (NH3), whose content was dependent on pH. Temperature was also found an important parameter and enhances DOX release at higher temperatures than the phase transition temperature of the lipid. A two-component liposomal system was proposed where ammonia (NH3) would be released from one liposome and enhance the DOX release from other liposomes. It was found that temperature, pH, and ammonia (NH3) concentration affected DOX release from liposomes. As a result, DOX was successfully loaded into liposomes and ready to study their effect on breast cancer cells.Master Thesis Design and Preparation of Alkali Liposomes for Drug Delivery(Izmir Institute of Technology, 2019) Güven, Hatice; Özdemir, Ekrem; Altun, Zekiye SultanCancer is one of the deadliest diseases among other illnesses as an uncontrolled cell division. Liposomal technology has commonly been used in cancer therapy. Chemotherapeutical drugs, genetic materials, different imaging agents can be carried with liposomes. They are preferred by several important characteristics that selective passive targeting of tumors, increased stability and therapeutic index (reducing toxicity) via encapsulation and increased circulation life times with size adjustments. One of the indicator in cell cycle is intracellular pH. The aim of this study is to produce PEGylated alkali liposomes to provide cellular uptake in cancer cells and prevent cell division by changing of intracellular pH. Combination of liposomal technology and alkaline therapy in cancer cells may lead to the development of therapeutic strategies without using any drug to overcome chemoresistance and cell proliferation. For this purpose, alkali liposomes containing sodium carbonate (Na2CO3) solution were prepared and tested their effects on 4T1 breast cancer cell lines in vitro. The cell viabilities were evaluated using trypan blue and WST-1 methods. Pictures were taken for cancer cells to differentiate live and dead cells under different alkali liposome conditions for 5 days. It was found that cell medium containing alkali liposomes up to 3% didn’t affect cell growth. However, cell medium containing alkali liposomes greater than 7% significantly affected the 4T1 breast cancer cell growth and decreased the cell viability to about 40%. It was concluded that PEGylated alkali liposomes were prepared different concentrations to decrease or stop cell division of 4T1 breast cancer cell lines in vitro.