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Study of interaction of negatively charged vesicular systems with polycations
Repová, Romana ; Klučáková, Martina (referee) ; Mravec, Filip (advisor)
This diploma thesis deals with the preparation and characterization of negatively charged catanionic vesicular systems and their combination with selected polycations. The catanionic vesicular system was prepared by mixing of two oppositely charged surfactants SDS and CTAB. The negative charge as well as the stability of the vesicular system was provided by the incorporation of phosphatidic acid. Polycations, DEAE and TMC, have been selected for use in a pharmaceutical applications. Characterization of the prepared systems was performed by measuring DLS and ELS. The results indicate that we were able to prepare stable negatively charged vesicles that were eligible to non-covalently interact with selected polycations.
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Preparation and characterization of catanionic complexes
Mušková, Alexandra ; Kalina, Michal (referee) ; Mravec, Filip (advisor)
The diploma thesis deals with the preparation and characterization of catanionic complexes and their possible application to pharmaceutics and medicine. The catanionic complexes were prepared by mixing two oppositely charged surfactants with the concentration of 20 mmol·dm3 in various volume ratios. Two systems were analyzed – CTAB + SDS and Septonex + SDS. Both systems were prepared in an aqueous and physiological environment. The turbidimetric analyses provided results of the intensity of turbidity of the prepared mixtures. The size and stability of the prepared particles were determined by DLS and ELS measurements. CTAB-rich samples showed significant viscosity changes and they were therefore characterized by rheological measurements. The results of this work show that the asymmetry of alkyl chains, surfactant selection, temperature, and ionic strength have a significant influence on the properties and self-assembly of surfactants in catanionic complexes.
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Preparation and characterization of quatsomes
Havlíčková, Anna ; Szabová, Jana (referee) ; Mravec, Filip (advisor)
This bachelor thesis deals with preparing and characterizing quatsomes and similar vesicular systems. The preparation consisted of weighing an equimolar amount of sterol and surfactant, hydration with deionized water, and subsequent sonication with an ultrasonic probe with an energy of 5, 10 and 15 kJ. In this work, two types of quatsomes were prepared, the first contained equimolar amounts of cholesterol and cetyltrimethylammonium bromide (CTAB), and the second consisted of cholesterol carbethopendecinium bromide (Septonex). The optimal dispersion energy of 10 kJ was selected for both types based on turbidity measurements, visual observation and dynamic and electrophoretic light scattering analysis. Furthermore, the observed properties were found to be constant from day 7 after sonication. In addition to quatsomes, similar vesicles were prepared, which contained a surfactant in the form of a sulfate salt. Once again, two types were prepared, the first containing sodium dodecyl sulfate (SDS) and cholesterol, the second sodium tetradecyl sulfate (STS) and cholesterol. Based on the same measurements as for quatsomes, optimal dispersion energy of 10 kJ was selected. Furthermore, mixtures with different ratios of cholesterol and a given surfactant were prepared, in which the effect of cholesterol addition was monitored. The analysis of these mixtures was performed by the same methods as the analysis of quatsomes.
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Interaction of negatively charged vesicular systems based on ionic amphiphilic pairs with polycations
Fardová, Lucie ; Venerová, Tereza (referee) ; Mravec, Filip (advisor)
This work is focused on the preparation of negatively charged vesicular systems from amphiphilic pairs deprived of counterions and their interaction with the polycation. First, vesicular systems were prepared from the surfactants sodium dodecyl sulfate and cetyltrimethylammonium bromide. The addition of cholesterol and phosphatidic acid stabilized and at the same time gained a negative charge. Subsequently, there was an interaction with the polycation diethylaminoethyl-dextran hydrochloride. The systems were investigated by the measuring of particle size, zeta potential, generalized polarization and anisotropy. The measurement of generalized polarization was enabled with the laurdan probe and measurement of anisotropy was performed with the introduction of the 1,6-diphenyl-1,3,5-hexatriene probe. The results indicate the successful preparation of stable, negatively charged systems that interacted with positive diethylaminoethyl-dextran hydrochloride, which affected the behavior of the outer membrane but not the inner. The systems were still stable.
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Preparation and characterization of quatsomes
Havlíčková, Anna ; Szabová, Jana (referee) ; Mravec, Filip (advisor)
This bachelor thesis deals with preparing and characterizing quatsomes and similar vesicular systems. The preparation consisted of weighing an equimolar amount of sterol and surfactant, hydration with deionized water, and subsequent sonication with an ultrasonic probe with an energy of 5, 10 and 15 kJ. In this work, two types of quatsomes were prepared, the first contained equimolar amounts of cholesterol and cetyltrimethylammonium bromide (CTAB), and the second consisted of cholesterol carbethopendecinium bromide (Septonex). The optimal dispersion energy of 10 kJ was selected for both types based on turbidity measurements, visual observation and dynamic and electrophoretic light scattering analysis. Furthermore, the observed properties were found to be constant from day 7 after sonication. In addition to quatsomes, similar vesicles were prepared, which contained a surfactant in the form of a sulfate salt. Once again, two types were prepared, the first containing sodium dodecyl sulfate (SDS) and cholesterol, the second sodium tetradecyl sulfate (STS) and cholesterol. Based on the same measurements as for quatsomes, optimal dispersion energy of 10 kJ was selected. Furthermore, mixtures with different ratios of cholesterol and a given surfactant were prepared, in which the effect of cholesterol addition was monitored. The analysis of these mixtures was performed by the same methods as the analysis of quatsomes.
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Interaction of negatively charged vesicular systems based on ionic amphiphilic pairs with polycations
Fardová, Lucie ; Venerová, Tereza (referee) ; Mravec, Filip (advisor)
This work is focused on the preparation of negatively charged vesicular systems from amphiphilic pairs deprived of counterions and their interaction with the polycation. First, vesicular systems were prepared from the surfactants sodium dodecyl sulfate and cetyltrimethylammonium bromide. The addition of cholesterol and phosphatidic acid stabilized and at the same time gained a negative charge. Subsequently, there was an interaction with the polycation diethylaminoethyl-dextran hydrochloride. The systems were investigated by the measuring of particle size, zeta potential, generalized polarization and anisotropy. The measurement of generalized polarization was enabled with the laurdan probe and measurement of anisotropy was performed with the introduction of the 1,6-diphenyl-1,3,5-hexatriene probe. The results indicate the successful preparation of stable, negatively charged systems that interacted with positive diethylaminoethyl-dextran hydrochloride, which affected the behavior of the outer membrane but not the inner. The systems were still stable.
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Preparation and characterization of catanionic complexes
Mušková, Alexandra ; Kalina, Michal (referee) ; Mravec, Filip (advisor)
The diploma thesis deals with the preparation and characterization of catanionic complexes and their possible application to pharmaceutics and medicine. The catanionic complexes were prepared by mixing two oppositely charged surfactants with the concentration of 20 mmol·dm3 in various volume ratios. Two systems were analyzed – CTAB + SDS and Septonex + SDS. Both systems were prepared in an aqueous and physiological environment. The turbidimetric analyses provided results of the intensity of turbidity of the prepared mixtures. The size and stability of the prepared particles were determined by DLS and ELS measurements. CTAB-rich samples showed significant viscosity changes and they were therefore characterized by rheological measurements. The results of this work show that the asymmetry of alkyl chains, surfactant selection, temperature, and ionic strength have a significant influence on the properties and self-assembly of surfactants in catanionic complexes.
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Study of interaction of negatively charged vesicular systems with polycations
Repová, Romana ; Klučáková, Martina (referee) ; Mravec, Filip (advisor)
This diploma thesis deals with the preparation and characterization of negatively charged catanionic vesicular systems and their combination with selected polycations. The catanionic vesicular system was prepared by mixing of two oppositely charged surfactants SDS and CTAB. The negative charge as well as the stability of the vesicular system was provided by the incorporation of phosphatidic acid. Polycations, DEAE and TMC, have been selected for use in a pharmaceutical applications. Characterization of the prepared systems was performed by measuring DLS and ELS. The results indicate that we were able to prepare stable negatively charged vesicles that were eligible to non-covalently interact with selected polycations.
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