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Transport of Biomedical Active Compounds Through Porous Membranes
Vašíčková, Kateřina ; Smilková, Marcela (referee) ; Smilek, Jiří (advisor)
This bachelor thesis deals with a study of transport of biomedical active compounds through porous membranes. The main goal is to optimize a penetration method of micellar solutions with a solubilized dye and subsequently with solubilized drug. Cetyltrimethylammonium bromide is chosen as a surfactant and a nile red dye is used as a diffusion and fluorescence probe. Selected active compound is a nonsteroidal anti-inflammatory drug ketoprofen with analgesic and antipyretic effects. The diffusion processes are realized using Franz diffusion cells with polycarbonate membrane with a 2 µm size of poruses. The samples are withdrawn in a chosen time intervals and afterwards evaluated by a fluorescence correlation spectroscopy. Using this method, it is possible to screen the diffusion in time even in nanomolar concentrations of a fluorescence probe chosen. This thesis provides an overview of nile red behaviour in the micellar solutions of surfactant during diffusion processes. The experiment can be extended using an active compound, for instance using a ketoprofen as it is mentioned above.
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Hyaluronan-Micelle Aggregates and their Potential for Nanomedicine Applications
Pilgrová, Tereza ; Burgert, Ladislav (referee) ; Reháková, Milena (referee) ; Pekař, Miloslav (advisor)
This thesis deals with the study of preparation and characterization of hyaluronan-micelle aggregates. The theoretical part deals with drug delivery systems, characterization of used materials and methods especially fluorescence spectroscopy, dynamic light scattering and turbidimetry. Methods of determination of measured data are summarized in the experimental section. The result section is divided into two subsections dedicated to different preparation methods of hyaluronan-surfactant complexes. Induced aggregates of hyaluronan with Septonex are characterized in terms of their origin and stability, and the results are compared with previously studied surfactants CTAB. In the second part are discussed so-called decorated micelles, their formation, properties and stability.
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Quality of hydrophobic domains in polyelectrolyte-surfactant system
Holínková, Petra ; Vala, Martin (referee) ; Mravec, Filip (advisor)
In this bachelor thesis were studied the photophysical properties of four fluorescent probes depending on the viscosity of their surroundings by the fluorescence spectroscopy. For probes DPH, DPB a perylene was determinated dependence of fluorescence anisotropy and for P3P dependence of ratio excimer/monomer on the viscosity of the sample. Anisotropy probes DPH and perylene were also used to study interaction between hyaluronan and cationic surfactant CTAB (concentration below CMC) in aqueous solution and 0,15 M NaCl. Information about forming hydrophobic domains were obtained by measurement of fluorescence intensity and anisotropy depending on the concentration of CTAB in the sample. It was found that in an aqueuos solution, after the initial addition of CTAB to hyaluronan formed small hydrophobic domains linked to chain of hyaluronan. Increasing concentration of CTAB leads to the formation of gel and phase separation. After addition of NaCl leads to reorganization of this system and probably the formation of free micelles in the solution with higher concentration of CTAB.
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Anisotropy and time-resolved anisotropy techniques in colloidal systems research
Holínková, Petra ; Táborský,, Petr (referee) ; Mravec, Filip (advisor)
In this diploma thesis were investigated in terms of microviscosity liquid and condensed systems composed of hyaluronan (Hya) and cationic surfactant cetyltrimethylammonium bromide (CTAB). The excitation and emission spectra, lifetime, steady-state fluorescence anisotropy and time-resolved fluorescence anisotropy of the samples were measured. First, was studied the formation of hydrophobic domains in the system Hya-CTAB at concentration of CTAB lower than its critical micelle concentration in an aqueous solution and 0.15M NaCl. It was found that in an aqueous solution small hydrophobic domains linked to chains Hya are formed. Then an increasing concentration of CTAB leads to phase separation and formation of gel. Due to the addition of NaCl then leads to the reorganization of this system and probably the formation of free micelles in the solution. Were also studied condensed phase of system Hya-CTAB-NaCl at high concentrations of surfactant during fourteen days of ageing. It was found that the microviscosity of hydrophobic domains is constant, but the microviscosity of hydrophilic parts gradually decreases.
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Excited-state proton transfer as a tool for characterization of coloid particles
Richterová, Veronika ; Pilgrová, Tereza (referee) ; Mondek, Jakub (advisor)
This bachelor thesis deals with the study of excited-state proton transfer in micellar systems. At first critical micelle concentration of surfactants CTAB, SDS and Triton X-100 was determined. Further the steady-state and time-resolved fluorescence of probes that undergo excited-state proton transfer with these surfactants was measured. As probes were chosen 1-naphthol, HPTS and 3HNA. Deprotonation rates of 1-napthol and HPTS and average lifetime of 3HNA were calculated from time-resolved measurement. Steady-state fluorescence was used for observation surfactants influence on excited-state proton transfer.
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Preparation and characterization of magnetic nanoparticles modified by surfactants
Solnička, Ondřej ; Másilko, Jiří (referee) ; Enev, Vojtěch (advisor)
Theme of this bachelors thesis was preparation and characterization of iron(II, III) oxide nanoparticles. Those nanoparticles were modified by surfactants. The surfactants which were used for modifiation were CTAB, TTAB and Septonex. Prepared and modified nanoparticles were taken for characterization by using methods of elemental analysis, thermogravimetry, dynamic light scattering and transmission electron microscopy (TEM). Results from each measurement shows that nanoparticles modified by CTAB had on average 85.9 nm in diameter, TTAB size was on average 108.3 nm and the last nanoparticles with Septonex had 246.6 nm in diameter on average. Prepared modified nanoparticles except the Septonex ones were stable enough to not aggregate. Septonex modified nanoparticles had greater tendenty to aggregate.
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Advanced Fluorescence Techniques in Research on Micellar Systems and Their Interactions with Biopolymers
Holínková, Petra ; Burgert, Ladislav (referee) ; Táborský, Petr (referee) ; Pekař, Miloslav (advisor)
The dissertation thesis deals with study of advanced steady-state and time-resolved fluorescence techniques, which can be used for study of micellar systems properties. Selected fluorescence techniques were used for characterization of Septonex and CTAB cationic micellar systems and theirs interactions with hyaluronan. Fluorescent probe pyrene was used for determination of critical micelle concentration (CMC) and micellar aggregation number of these surfactants. The changes of fluorescence behaviour of fluorescein and prodan were studied in wide concentration range of Septonex. Next chapter of thesis deals with study of Förster resonance energy transfer between perylene and fluorescein in Septonex and CTAB micellar solutions and the effect of hyaluronan addition to these systems. Also steady-state and time-resolved fluorescence anisotropy studies were used for research of the effect of hyaluronan addition to micellar solutions. The last chapter of this thesis is focused on photophysical behaviour of Prodan in different solutions (water, Septonex solutions below CMC, hyaluronan solution, Septonex micellar solution and Septonex micellar solution with hyaluronan), which was discussed on the basis of time-resolved emission spectra.
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Influence of molecular weight of polymers on phase-separated hydrogels
Kolomá, Nikola ; Smilek, Jiří (referee) ; Mravec, Filip (advisor)
This work is focused on study of individual systems of hyaluronan mixtures. All mixtures of hyaluronans they were ready at molecular weights of 15-30 kDa, 80-150 kDa, or 1500-1750 kDa. These individual molecular weights were combined in different ratios most often in ratios of 70:30, 50:50 and 30:70. Septonex surfactant was used for all mixed samples and CTAB was used for last experiment too. At first the gel samples were prepared by a dry route of individual powders with accurately calculated batches. All solutions were prepared wet route with stock of exactly calculated concentration. Physical gels were prepared by combinations of Septonex and hyaluronan with the different molecular weights. In solution formed irregular shapes which we could describe as "marbles" or "beads". After the sample was to stand, the individual „marbles“ of the gel were formed whole mass. Was done too many experiments with physical gels, which has been carried out behavior of mixtures hyaluronans with different molecular weights. All physical and chemical properties were observed by the eye, described and in the and were photographed. Was used hydrophil dye in experiments and served for better visualize comparison samples between themselves. The last experiment was rheological measurement with which is possible characterize viscosity od individual samples.
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Hyaluronan-Micelle Aggregates and their Potential for Nanomedicine Applications
Pilgrová, Tereza ; Burgert, Ladislav (referee) ; Reháková, Milena (referee) ; Pekař, Miloslav (advisor)
This thesis deals with the study of preparation and characterization of hyaluronan-micelle aggregates. The theoretical part deals with drug delivery systems, characterization of used materials and methods especially fluorescence spectroscopy, dynamic light scattering and turbidimetry. Methods of determination of measured data are summarized in the experimental section. The result section is divided into two subsections dedicated to different preparation methods of hyaluronan-surfactant complexes. Induced aggregates of hyaluronan with Septonex are characterized in terms of their origin and stability, and the results are compared with previously studied surfactants CTAB. In the second part are discussed so-called decorated micelles, their formation, properties and stability.
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Fluorescence correlation spectroscopy in colloid systems
Janíček, Tomáš ; Smilek, Jiří (referee) ; Mravec, Filip (advisor)
This work is focused on studying of stability and interaction in colloidal systems created by micelles of surfactant CTAB in solution of hyaluronic acid and water. As method chose for this work was selected fluorescence correlation spectroscopy. As dye was used Nile red. Measurements were divided firstly by size of polymeric chain and secondly by concentration of hyaluronic acid. Purpose of this work was to find out how will CTAB particles react with different sizes and concentration of hyaluronic acid. For comparison to hyaluronic acid was used Poly(sodium-4-styrenesulfonate).
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