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Immobilization of Thermophilic Esterase on Magnetic Cornstarch Nanoparticles for Biological Applications
(Izmir Institute of Technology, 2016) Öz, Yasin; Şanlı Mohamed, Gülşah; Şanlı Mohamed, Gülşah; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
In last three decades, even the role of enzymes for biological and industrial applications has become more worthy, enzymes also have some defects. The enzyme immobilization allows to overcome these defects by improving abilities of reusing of catalysts by multiple times, easier reactor operation and product separation. Due to its potential use in biological and industrial applications, isolated thermophilic esterase from Geobacillus sp. was immobilized on magnetic cornstarch nanoparticles. In order to determine activity performance of immobilized enzyme, the effects of temperature, pH and some chemicals on enzyme activity were investigated. The results have shown that after immobilization, the relative activity of immobilized esterase has increased to 80% at 80 0C in comparison to free esterase. Therewithal, the reusability of immobilized esterase has increased fourfold in comparison to free esterase. The magnetic character of the support media has brought ease to separate biocatalysts from reaction media.
Chitosan-Plasmid Dna Nanoparticles: Cytotoxic and Cytostatic Effects on Human Cell Lines
(Izmir Institute of Technology, 2015) Bor, Gizem; Demir, Mustafa Muammer; Şanlı Mohamed, Gülşah; Şanlı Mohamed, Gülşah; Demir, Mustafa Muammer; 03.09. Department of Materials Science and Engineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
Although chitosan nanoparticles (CNs) became a promising tool for several biological and medical applications owing to their inherent biocompatibility and biodegrability, studies regarding their effects on cytotoxicity and cytostatic properties still remain insufficient. Therefore, in the present study, we decided to perform comprehensive analysis of the interactions between CNs – pKindling-Red-Mito (pDNA) and different cell line models derived from blood system and human solid tissues cancers. The resulting CNs-pDNA was investigated with regard to their physical-chemical properties, cellular uptake and transfection efficiency, cytotoxic and cytostatic properties. The nanoparticles showed high encapsulation efficiency and physical stability even after 2 days for various formulations. Moreover, high gene expression levels were observed already 96 h after transfection. CNs-pDNA treatment, despite the absence of oxidative stress induction, caused cell cycle arrest in G0/G1 phase and as consequence led to premature senescence, which turned out to be both, p21-dependent and p21-independent. Also, observed DNMT2 upregulation may suggest the activation of different pathways protecting from the resulting CNs-mediated stress. In conclusion, treatment of different cell lines with CNs-pDNA showed that their biocompatibility was limited and effects were cell type-dependent.
Immobilization of Olive Leaf Extract on Chitosan Nanoparticles and Investigation of Their Effects on Cancer Cell Lines
(Izmir Institute of Technology, 2014) Özdamar, Burcu; Şanlı Mohamed, Gülşah; Şanlı Mohamed, Gülşah; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Cancer incidence and mortality rates are increasing worldwide in both economically developed and developing countries. Breast cancer in females and lung cancer in males are the most common cancer types. Epidemiological research has provided increasing evidence that dietary habits, especially Mediterranean diet which has high consumption of olive oil and its products, may play an important role in lung and breast cancer. Due to their preventive effect against cancer, olive leaf extract rich in polyphenols was immobilizied on chitosan nanoparticles which are good drug carriers because of their biocompatible and biodegradable properties with the help of capability of passing through biological barriers. For this aim, olive leaf extract loaded chitosan nanaoparticles were synthesized by ionotropic gelation mechanism. Optimum conditions to synthesize nanoparticles were determined by investigation of the effect of chitosan and tripolyphosphate mass ratio, initial pH of chitosan solution, concentration of olive leaf extract and incubation time of olive leaf extract and tripolyphosphate with chitosan solution. Characterization of nanoparticles was performed by dynamic light scattering, atomic force microscopy and infrared spectroscopy. To investigate the anticancer properties of nanoparticles, molecular biological studies were performed by in vitro cytotoxicity studies based on MTT assay, in vitro cell cycle analysis and apoptosis by flow cytometer and imaging of cells by optical microscopy. In results, olive leaf extract loaded chitosan nanaoparticles obtained approximately 91.25 nm and showed more cytotoxicity than chitosan nanoparticles, chitosan and olive leaf extract for both lung and breast cancer cells. In contrast, there was no cytotoxicity for healthy cells. These effects were supported by cell cycle analysis. Also in optical imaging, lower number of cells and morfological differences on cancerous cells which supports the cytotoxicity results were observed. We can conclude that our results will open a new approach to use not only cytotoxic anticancer drug for cancerous cells but also biocompatible material for biomedical applications.

Master Degree / Yüksek Lisans Tezleri

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