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Optimization of separation conditions for HPCCC of paclitaxel
Havrlantová, Šárka ; Kučera, Radim (advisor) ; Šatínský, Dalibor (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Šárka Havrlantová Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Name of diploma thesis: Optimization of separation conditions for HPCCC of paclitaxel The aim of this work is a feasibility study of natural substances isolation (in my case it is paclitaxel and its intermediate 10-deacetylbaccatin) using modern technique called High performance countercurrent chromatography (HPCCC) available in Teva in Opava. For this basic research it was necessary to study the literature and test various solvent systems. Chosen solvent systems were then tested together with natural substance in HPCCC, results were processed and discussed. Countercurrent chromatography is considered a modern separation technique based on two immiscible liquids. One of them is called a stationary phase and is held inside the column by centrifugal force, the second liquid is called a mobile phase and is pumped through the column. Then the injected liquid sample is also pumped through the column and depending on distribution coefficients the sample components are either held in the stationary phase or pass through the column and detector into fraction collector. Advantages of this method are e.g. total...
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Aliphatic polyester-based nanoparticles as drug delivery systems
Jäger, Alessandro ; Štěpánek, Petr (advisor) ; Sedláček, Jan (referee) ; Sikora, Antonín (referee)
Nanoparticles from biodegradable polymers are considered one of the most promising systems for biomedical application as drug delivery systems. Therefore, the synthesis and characterization of a new aliphatic biodegradable copolyester named PBS/PBDL (poly(butylene succinate-co- butylene dilinoleate)) intended to the application as drug delivery system is reported in the thesis. Surfactant-free biodegradable and narrowly distributed, nanosized spherical particles (RH < 60 nm) have been produced from the biodegradable material by applying a single-step nanoprecipitation protocol. The size of the generated polymer nanoparticles (PNPs) could be controlled by adjusting the polymer concentration, the choice of organic solvent, mixing different organic solvents or by changing temperature and ionic strength. By optimizing such parameters sub-100 nm uniform PNPs can be produced through this methodology including the advantage and ability to scale-up production. The nanoparticles structure was characterized in detail by employing a variety of scattering techniques and transmission electron microscopy (TEM). Combined static light scattering (SLS) and dynamic light scattering (DLS) measurements suggested that the nanoparticles comprise a porous core conferring them a non-compact characteristic. Their porosity...
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The role of TLR-4 receptors for modulation of nociceptive signalling.
Slepička, Jakub ; Paleček, Jiří (advisor) ; Zímová, Lucie (referee)
The ability to feel pain is subjective, but a crucial factor allowing us to maintain life with minimal body impairment. However, if the pain crosses the physiological signalling function it becomes a life restrictive symptom that is often difficult to treat. Development of pain and its change into pathological chronic symptom and the role of different molecular and cellular mechanisms in this process are best to be studied during its development, nociception. In this work the basic characteristics of nociceptive signalling, with focus on neuropathy, a state originating from nervous system damage is given. The exact mechanisms of neuropathic pain development are not known, which is one of the reasons why these painful states are difficult to treat. Neuroinflammation was lately shown to play an important part in the neuropathy development. In this context a review of Toll-like receptors is given. These receptors have a fundamental role in the innate immunity and their role in the nervous system was documented recently. In this review a focus is given on TLR-4 subtype that was shown to be involved in a modulation of nociceptive signalling. The basic features of this receptor and information about its involvement in neuropathic pain development are given. Studying the role of TLR-4 in different models...
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Molecular mechanisms of the resistence of breast cancer cells to taxanes: the role of ABC transporters
Kopperová, Dana ; Kovář, Jan (advisor) ; Hrdý, Jiří (referee)
Resistance to chemotherapeutics is a widespread phenomenon in cancer cells that may counteract the successful therapy of many patients. In resistant cells, higher level of ABC transporters, among others, often can be detected. This high level of ABC transporters represents a suspected mechanism of acquired cancer resistance. We studied the molecular mechanism of resistance to taxanes in cancer cells using SK-BR-3 and MCF-7 breast cancer cell lines. We analyzed the effect of paclitaxel on apoptosis induction in the originally sensitive cells of these lines as compared to their counterpart resistant cells, developed by gradual adaptation to paclitaxel. In resistant cells of the SK-BR-3 and MCF-7 lines, we did not detected ongoing induction of apoptosis but we did detect significantly increased expression of ABCB1 transporter after paclitaxel application. By silencing the expression of the transport via employment of small interfering RNA (siRNA), we tested the role of the ABCB1 transporter in cells resistant to paclitaxel. We found that resistant cells with silenced expression of the ABCB1 transporter had a statistically significant increase of sensitivity to paclitaxel as compared to control resistant cells with high expression of this transporter. Along with increased sensitivity, we demonstrated...
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Microtubule-active drugs: mechanism of action and resistance
Dostál, Vojtěch ; Libusová, Lenka (advisor) ; Rösel, Daniel (referee)
Microtubular cytoskeleton represents a target for a myriad of diverse chemical compounds, referred to as microtubule-active drugs. Produced by certain plants, animals or microbes, the substances often effectively elicit cell death - especially in animals and also in plants to a certain extent, but never in species which produce them to defend against their predators. Nowadays, several microtubule-active substances constitute hallmarks of anti-cancer treatment and agricultural weed control. There is an enormous sum of knowledge about the action of paclitaxel (taxol), vinca alkaloids and colchicine, three best-known microtubule active compounds used in medicine, and new research often challenges the previously accepted theories. This work investigates the mechanism of action of microtubule-active drugs from the angle of biochemistry and cell biology, as well as from the physiological standpoint. Effects on microtubule levels and dynamics and the path towards the cell death are reviewed. In the last chapter, attention is given to drug activity in both animal and plant bodies and, finally, to drug-producing plant species which often show substantial resistance.
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Preparation and characterization of nanoliposomal carriers of hydrophobic cytostatics using nanofluidic mixing
Zelníčková, Jaroslava ; Mašek,, Josef (referee) ; Turánek, Jaroslav (advisor)
This diploma thesis is focused on preparation of liposome by relatively new method called nanofluidisation. This method allows the controlled preparation of small unilamellar liposomes in one step. In my thesis I was dealing with optimalization of liposomes preparation which carry hydrophobic cytostatics using this method. Cytotoxic effect of liposomes carrying hydrophobic cytostatics in vitro on cell lines A549 and MCF-7 was determined. In cytotoxicyty test I compared the effect of hydrophobic cytostatics (paclitaxel and derivates of vitamin E specifically alfa-Tos, alfa-TEA) that were incorporated into liposomes prepared via nanofluidisation method and lipid film hydration method. Moreover, a technology of lyophilisation in the presence of cryoprotectants for preparation of liposomes using the method of nanofluidisation was developed.
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Relationship of selected indicators of nutritional status and results of oesophageal cancer treatment with chemoradiotherapy and surgery
Zemanová, Milada ; Tvrzická, Eva (advisor) ; Vaňásek, Jaroslav (referee) ; Kazdová, Ludmila (referee)
The impact was assessed of clinical and nutritional factors on prognosis of 107 oesophageal cancer patients treated with neoadjuvant chemoradiotherapy (CHRT) and surgery. Individualised nutritional support, according to grade of dysphagia was carried out in all the patients. Serum leptin, soluble leptin receptors (SLR), TNF, IGF and fatty acid (FA) profiles in plasma phosphatidylcholine (PC) were studied as well. Addition of paclitaxel to carboplatin and continual fluorouracil significantly increased toxicity without influencing efficacy of the treatment. Post-operative node negativity, grade of dysphagia, weight loss and serum albumin were proved to be prognostic factors of survival and time to progression. CHRT led to decrease of SLR, palmitoleic and oleic acid and increase of n-3 polyunsaturated FA in PC. Lower concentrations of SLR were associated with improved survival of the patients. Key words: oesophageal cancer, neoadjuvant chemoradiotherapy, weight loss, paclitaxel, albumin, soluble leptin receptor, fatty acids
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