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Characterization catanionic vesicular system by HRUS
Kopřivová, Hana ; Sovová, Šárka (referee) ; Hurčíková, Andrea (advisor)
This bachelor thesis is about catanionic vesicular systems, which could serve as carriers of drugs or genes in the future. These systems are prepared from the cationic surfactants CTAB and DDAC, the anionic surfactant SDS and cholesterol, which serves as a stabilizer. In the experimental part, these vesicles were characterized by high-resolution ultrasonic spectroscopy. The behavior of systems with different percentages of cholesterol was monitored. As next, the temperature properties of the vesicles were studied using temperature scans between 10 °C and 65 °C. The density of the samples was examined by densitometry at temperatures of 25 °C and at a human body temperature of 37 °C.
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Influence of concentration of surfactant component and temperature on interactions between hyaluronan and katanionic vesicular systems
Janáková, Kristýna ; Jugl, Adam (referee) ; Krouská, Jitka (advisor)
The influence of various concentrations of surfactant component and various temperatures on interactions of hyaluronan with catanionic vesicular systems were examined using isothermal titration calorimetry. The measurements were performed at two different concentrations of surfactant component and three temperature values. The reason for studying the interactions was to explore the possibility of these systems serving as carriers of drugs in the future. Catanionic vesicular systems consisted of a cationic surfactant CTAB, an anionic surfactant SDS and of a positively charged two-chain surfactant DODAC. The solution of negatively charged hyaluronan with concentration of 0,5 mM was used for all measurements.
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Solubilization in catanionic surfactant systems
Konečná, Anna ; Krouská, Jitka (referee) ; Mravec, Filip (advisor)
This bachelor thesis deals with the solubilization of hydrophobic dyes in systems of positively charged catanionic vesicles. The aim of the work was to determine their solubilization capacity. Vesicular systems were prepared from oppositely charged surfactants CTAB and SDS. To increase the stability of the vesicles, cholesterol and the positively charged double-chain surfactant DODAC were added to their structure. DODAC also gave the system a positive charge. To determine the solubilization capacity, the dyes 1-Naphthol, Sudan Red G and Oil Red O were used. For sample preparation two methods were used, spontaneous and direct solubilization. The measurement was performed after 1, 2, 3 and 7 days from the preparation of the samples by UV-VIS spectrophotometry. The solubilization capacity was determined from the measured absorbance by calculation from the calibration curves. The results indicate that direct solubilization is slightly more effective than spontaneous solubilization. Of the selected dyes, 1-Naphthol is the substance with the smallest molecule, and therefore it seems to be 100% solubilized in the vesicle system.
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Study of the hydration shell of vesicular systems based on ionic amphiphilic pairs
Rašticová, Barbora ; Szabová, Jana (referee) ; Mravec, Filip (advisor)
This bachelor thesis deals with the study of hydration shell of positively charged vesicular systems. The aim of the work was to monitor the hydration shell and to find out the amount of water molecules in the environment at different conditions of the membrane. Furthermore, a comparison of two selected fluorescent probes were studied. Positively charged vesicular systems composed of two types of surfactants were used, namely negatively charged SDS and positively charged CTAB. The two-chain positively charged surfactant was also added, resulting a positively charged vesicular systems. Three different concentrations of cholesterol were selected for the study and added to the system, namely 20, 40 and 60 mol. %. The study was performed by measuring the fluorescent emission as a function of temperature. The temperature range was from 10 to 80 °C. As a fluorescent probe Laurdan and Prodan were selected. For evaluation the method of generalized polarization was used. Due to its structure, Laurdan is mainly found in the membrane environment, so the method of two-wavelength generalized polarization, which includes fluorescence contributions only from the membrane, was sufficient for its evaluation. Compared to Laurdan, Prodan has a shorter hydrocarbon chain, so its distribution is not only in the membrane but also in the aqueous environment. Therefore, the method of three-wavelength generalized polarization, which also includes the contribution of fluorescence from the aqueous environment was used. The results showed that the behaviour of both probes is very similar. In all systems, the values of generalized polarization decreased with increasing temperature. Thus, at low temperatures, the membrane is in a solid ordered phase. With increasing temperature, it transforms into a liquid disordered phase. Thus, with increasing temperature, the number of water molecules increases. As the cholesterol concentration increased, the phase transition interval increased. The results also showed that the values of Prodan’s three wavelength generalized polarization are always higher than the values of Laurdan’s two wavelength generalized polarization.
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Study of the hydration shell of vesicular systems based on ionic amphiphilic pairs
Rašticová, Barbora ; Szabová, Jana (referee) ; Mravec, Filip (advisor)
This bachelor thesis deals with the study of hydration shell of positively charged vesicular systems. The aim of the work was to monitor the hydration shell and to find out the amount of water molecules in the environment at different conditions of the membrane. Furthermore, a comparison of two selected fluorescent probes were studied. Positively charged vesicular systems composed of two types of surfactants were used, namely negatively charged SDS and positively charged CTAB. The two-chain positively charged surfactant was also added, resulting a positively charged vesicular systems. Three different concentrations of cholesterol were selected for the study and added to the system, namely 20, 40 and 60 mol. %. The study was performed by measuring the fluorescent emission as a function of temperature. The temperature range was from 10 to 80 °C. As a fluorescent probe Laurdan and Prodan were selected. For evaluation the method of generalized polarization was used. Due to its structure, Laurdan is mainly found in the membrane environment, so the method of two-wavelength generalized polarization, which includes fluorescence contributions only from the membrane, was sufficient for its evaluation. Compared to Laurdan, Prodan has a shorter hydrocarbon chain, so its distribution is not only in the membrane but also in the aqueous environment. Therefore, the method of three-wavelength generalized polarization, which also includes the contribution of fluorescence from the aqueous environment was used. The results showed that the behaviour of both probes is very similar. In all systems, the values of generalized polarization decreased with increasing temperature. Thus, at low temperatures, the membrane is in a solid ordered phase. With increasing temperature, it transforms into a liquid disordered phase. Thus, with increasing temperature, the number of water molecules increases. As the cholesterol concentration increased, the phase transition interval increased. The results also showed that the values of Prodan’s three wavelength generalized polarization are always higher than the values of Laurdan’s two wavelength generalized polarization.
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Influence of concentration of surfactant component and temperature on interactions between hyaluronan and katanionic vesicular systems
Janáková, Kristýna ; Jugl, Adam (referee) ; Krouská, Jitka (advisor)
The influence of various concentrations of surfactant component and various temperatures on interactions of hyaluronan with catanionic vesicular systems were examined using isothermal titration calorimetry. The measurements were performed at two different concentrations of surfactant component and three temperature values. The reason for studying the interactions was to explore the possibility of these systems serving as carriers of drugs in the future. Catanionic vesicular systems consisted of a cationic surfactant CTAB, an anionic surfactant SDS and of a positively charged two-chain surfactant DODAC. The solution of negatively charged hyaluronan with concentration of 0,5 mM was used for all measurements.
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Solubilization in catanionic surfactant systems
Konečná, Anna ; Krouská, Jitka (referee) ; Mravec, Filip (advisor)
This bachelor thesis deals with the solubilization of hydrophobic dyes in systems of positively charged catanionic vesicles. The aim of the work was to determine their solubilization capacity. Vesicular systems were prepared from oppositely charged surfactants CTAB and SDS. To increase the stability of the vesicles, cholesterol and the positively charged double-chain surfactant DODAC were added to their structure. DODAC also gave the system a positive charge. To determine the solubilization capacity, the dyes 1-Naphthol, Sudan Red G and Oil Red O were used. For sample preparation two methods were used, spontaneous and direct solubilization. The measurement was performed after 1, 2, 3 and 7 days from the preparation of the samples by UV-VIS spectrophotometry. The solubilization capacity was determined from the measured absorbance by calculation from the calibration curves. The results indicate that direct solubilization is slightly more effective than spontaneous solubilization. Of the selected dyes, 1-Naphthol is the substance with the smallest molecule, and therefore it seems to be 100% solubilized in the vesicle system.
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Characterization catanionic vesicular system by HRUS
Kopřivová, Hana ; Sovová, Šárka (referee) ; Hurčíková, Andrea (advisor)
This bachelor thesis is about catanionic vesicular systems, which could serve as carriers of drugs or genes in the future. These systems are prepared from the cationic surfactants CTAB and DDAC, the anionic surfactant SDS and cholesterol, which serves as a stabilizer. In the experimental part, these vesicles were characterized by high-resolution ultrasonic spectroscopy. The behavior of systems with different percentages of cholesterol was monitored. As next, the temperature properties of the vesicles were studied using temperature scans between 10 °C and 65 °C. The density of the samples was examined by densitometry at temperatures of 25 °C and at a human body temperature of 37 °C.
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