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The study of properties of anticancer drugs ellipticine, etoposide and doxorubicin in the forms of nanocarriers
Lengálová, Alžběta ; Stiborová, Marie (advisor) ; Martínková, Markéta (referee)
Currently available anticancer therapies are inadequate and spur demand for improved technologies. Among others, the utilization of nanocarriers for anticancer drug delivery has shown great potential in cancer treatment. Nanocarriers can improve the therapeutic efficiency of the drugs with minimization of the undesirable side effects. To evaluate potential application of this technology, two forms of nanocarriers have been studied: multi-walled carbon nanotubes (MWCNTs) and apoferritin. The aim of this study was to determine, whether given cytostatics (ellipticine, etoposide and doxorubicin) are bound to these nanotransporters and how are they released from them, especially depending on pH. Since the pH of the tumor cells is lower than the pH of healthy cells it would be preferred that the drugs would release from nanocarriers at the lower pH while at the physiological pH the release of the drug would be eliminated. The results found show that ellipticine is actually released from its MWCNT- and apoferrtin-encapsulated form at acidic pH (5.0), while at pH 7.4 its interaction with nanocarriers is stable. Ellipticine released from MWCNT is activated by microsomal enzymes to reactive metabolites (13- hydroxyellipticine and 12-hydroxyellipticine) forming DNA adducts. The results indicate that both...
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Study of expression of transferrin receptors (TfR1) and their utilization in nanomedicine
Krausová, Kateřina ; Fohlerová, Zdenka (referee) ; Heger,, Zbyněk (advisor)
Bachelor thesis deals with the expression of the transferrin receptor (TfR1) and its use in nanomedicine. During the last decade, nanotechnology emerged as one of the central milestones in connecting all scientific and technological disciplines. Nanomedicine already demonstrated efficacy not only in animal models of cancer but also in clinical practice. The theoretical part is not only aimed at cancer of the human population, but also at the possibilities of targeted drug delivery into the tumor tissue, which greatly reduces the otherwise serious side effects of conventional treatment – systemic toxicity. The practical part is focused on optimization for studying the expression of the transferrin receptor, a protein overexpressed by neoplastic cells aiming to enrich the higher metabolic needs of tumor cells. The optimal conditions were as follows: lysate of 50 000 cells applied with nonreducing nondenaturing buffer and the concentration of the primary antibody of 1.0 𝜇g/ml. Different levels of TfR1 expression were detected, depending on the type of tumor cells. The cell lines of neuroblastoma, prostate cancer (occurence in every 7th man) and breast cancer (occurence in every 8th woman) were selected for the next experiments. Via this transferrin receptor, apoferritin, which is a protein storaging iron ions in many organisms, can be internalized into cells. Artificially, the internal cavity of apoferritin may be used for encapsulation and transport of any molecules. In the case of this bachelor thesis, the apoferritin was used for delivery of doxorubicin. Doxorubicin has been used for cancer treatment for more than 30 years; however, its administered dose is limited by its high toxicity. This can be reduced by its encapsulation in a suitable vector for targeted transport to the tumor cells only. Apoferritin could serve as such suitable vector. In this thesis, the suitable usage of apoferritin as a nanocarrier for chemotherapeutic delivery was confirmed. Its molecule size of 10-12 nm allows it to employ the effect of increased permeability and retention. At the same time, this size makes it possible to avoid renal clearance. The properties of encapsulated doxorubicin are not affected by apoferritin, thus preserving its toxicity for cells with a high level of TfR1 expression (30% growth inhibition of these cells after 24 h of treatment).
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