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Využití elektrochemických technik pro studium apoferritinu
Venusová, Eva
Theme of this diploma thesis is usage of electrochemical techniques for study of apoferritin, which is artificially synthetized protein derived from ferritin. Apoferritin has empty cavity which can be used for completion of broad amount of substances. Encapsulation of anticancer drugs can decrease their unwanted side effects such as strong toxicity and therefore increase it’s effectiveness at the tumor site. Substances chosen in this diploma thesis were standard platinum and platinum drugs cisplatin and it’s analogy oxaliplatin. Measurement was performed by electrochemical method differential pulse voltammetry by which was determined encapsulation capacity of apoferritin for chosen anticancer drugs. For determination size and zeta potential of nanoparticles was used colloid analyzator ZetaSizer Nano.
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Nanoparticle forms of anticancer drugs and the mechanisms influencing their efficiency
Urbanová, Tereza ; Stiborová, Marie (advisor) ; Hýsková, Veronika (referee)
Currently, cancer is one of the major diseases of civilization. The disadvantage of conventional chemotherapy, which began in the 1940s, is its non-specific effect, so the cytostatics are toxic to healthy cells. However, if the cytostatic is inserted into a nanotransporter, it increases its specific efficacy and reduces the negative side effects. One of the possible nanotransporters is protein called apoferritin (a protein component of ferritin, an iron-carrying protein) that contains light and heavy subunits differing in their function in iron uptake. In this bachelor thesis, the ability of apoferritin to encapsulate two cytostatics (ellipticine and doxorubicin), depending on its origin and the proportion of light and heavy apoferritin subunits, was studied.
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Biocompatible protein cages for encapsulation and internatization of small interfering RNA
Mokrý, Michal ; Balvan, Jan (referee) ; Heger, Zbyněk (advisor)
This thesis is focused on creation of apoferritin nanocarrier with encapsulated small interfering RNA marked with fluorescent dye. Main objectives are optimization of pH and amount of siRNA encapsulated into apoferritin cavity and physicochemical characteristics of created nanocarrier. First part deals with theoretical knowledge necessary for understanding concept of this thesis. Second part describes used methods and evaluated results. Created apoferritin nanocarriers were optimal in size with great hemocompatibility, but long-term stability didn’t meet our expectations.
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Preparation of anticancer drugs bound in apoferritin
Fürbacherová, Pavlína ; Indra, Radek (advisor) ; Koblihová, Jitka (referee)
Cancer is one of the most serious problems, which modern medicine faces. In recent years, nanotechnologies and their use in medicine, has developed greatly. The aim is to make drug administration more effective and help to improve treatment of cancer illnesses. Incorporation of chemical substance into a nanoparticle can solve the problem with low stability of the drug, and/or it help to eliminate side effects. Nanoparticle apoferritin, which was studied in this thesis, is a form of commonly occurring protein ferritin. Its structure contains cavity, that can be used for incorporation of drug. Its chemical structure (high temperature stability and stability at wide pH range, easy manipulation by changing pH) and its biocompatibility makes apoferritin a potentionally suitable transporter. Presented thesis studied apoferritin's ability to incorporate anticancer drug cabozantinib into its structure. Cabozantinib is tyrosine kinase inhibitor which is used for treatment of thyroid cancer, renal cell carcinoma and hepatocellular carcinoma. The effect of final pH to the formation of the complex of apoferritin with cabozantinib, and stability of this complex was also studied in this thesis. Considering the results we can say that apoferritin is able to encapsulate cabozantinib into its inner structure. As we...
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The study of properties of anticancer drugs ellipticine, etoposide and doxorubicin in the forms of nanocarriers
Lengálová, Alžběta
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 the mechanism of anticancer drug action on neuroblastomas
Černá, Tereza ; Stiborová, Marie (advisor) ; Souček, Pavel (referee) ; Mrízová, Iveta (referee)
Despite advances in cancer diagnosis and therapy, cancer is the second leading cause of death globally. The improvements of cancer treatment are the major challenge in this research. The aim of the thesis was studying of effects of two anticancer drugs ellipticine (Elli) and doxorubicin (DOX) on some cancer and healthy cell lines. Specific consideration was given to expand current knowledge about the metabolism and cytostatic effects of Elli in neuroblastoma cell lines. Another part of this study was focused on mechanisms contributing to the development of ellipticine-resistance in cancer cells and influence of histone deacetylase inhibitors on anticancer therapy was investigated. Moreover, the aim was to develop apoferritin (Apo) nanocarrier suitable for the active transport of cytostatics to cancer cells. Several essential data were found in this doctoral thesis. Anticancer efficiency of Elli depends on the CYP3A4-mediated metabolism in cancer. The CYP3A4 enzyme encapsulated into two nanoparticle forms, liposomes and SupersomesTM , was tested to activate ellipticine to its reactive species forming covalent DNA adducts. The formation of adducts seems to be dependent on concentrations of CYP3A4 in nanoparticle systems. A higher effectiveness of CYP3A4 in SupersomesTM than in liposomes to form...
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Preparation of drugs in nanoparticles for targeted treatment of cancer
Jáklová, Kateřina ; Indra, Radek (advisor) ; Bělonožníková, Kateřina (referee)
The aim of this thesis was to study the ability of the apoferritin to encapsulate drugs vandetanib and etoposid. Vandetanib is an anticancer drug used for the treatment of tumors of the thyroid gland. It acts as an inhibitor of tyrosine kinase receptor. Etoposid, which is widely used for the treatment of malignant blood diseases or solid tumors inhibits type II topoisomerase that regulates topology of DNA. Targeting treatment with nanoparticles can minimize adverse effects connected with both drugs. An apoferritin is a naturally occurring protein that is composed of 24 ferritin subunits. Its structure creates an internal cavity that can be loaded by any compoundands. The structure is remarkably stable and is able to withstand biologically extreme temperatures (up to 70řC) and a wide pH range (pH 2-10). Furthermore, apoferritin can move undetected through the body without any immune response. It is also possible to modify its surface by ligands specific for targeting tissues. The effect of the concentration of apoferritin and the effect of the concentration of the drug on the final concentration of the encapsulated drug was studied. In addition, even the effectiveness of encapsulation was studied. In the case of vandetanib, at a constant concentration of drug and an increasing concentration of...
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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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