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Rheological characterization of polysaccharide gels with incorporated vesicles
Kalendová, Lucie ; Smilek, Jiří (referee) ; Venerová, Tereza (advisor)
This diploma thesis deals with the rheological characterization of polysaccharide gels with incorporated vesicular systems. Positively charged Ion Pair Amphiphile vesicles (IPA) consisting of cetrimethylammonium bromide, sodium dodecyl sulfate, dioctadecyldimethylammonium chloride and cholesterol were chosen for the incorporation. Other vesicles used for incorporation were oppositely charged liposomes made of phosphatidylcholine (DPPC), phosphatidic acid (PA) and cholesterol. The thesis is divided into two sections. The first one deals with preparation, characterization and stability control (temperature and time stability) of both vesicular systems by using dynamic light scattering (DLS). In this part, the vesicles’ stability was confirmed which made them perfect candidates for the following incorporation. The second part of the thesis describes the preparation and rheological characterization of selected gels. Three types of gels were prepared in total, specifically 1% and 2% gellan gum gels and 4% hyaluronic gel. All of them were studied in water, as well as in solutions of IPA vesicles or DPPC liposomes, both of same concentration (1 mmoll-). The subsequent rheological characterization including amplitude, frequency, and stress relaxation sweeps demonstrates there is no significant difference between reference gels and those containing vesicles. This indicates that vesicles used in this thesis were only freely stored in the gel networks, meaning the structure of the gels didn’t affect their transport properties. This is a significant information for using these systems in drug delivery.
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Transport and mechanical properties of hybrid hydrogel networks based on gellan
Sokolínský, Jan ; Pekař, Miloslav (referee) ; Kalina, Michal (advisor)
This diploma thesis deals with the characterization of the mechanical and transport properties of gellan based hybrid hydrogels. As part of this work, the process of optimizing the preparation of gellan-poly(vinylalcohol) IPN hydrogel was first studied with an emphasis on the repeatability of the preparation due to the preservation of mechanical properties of the hydrogel. Then, both on the gellan hydrogels themselves and on selected IPN compositions, the effect of various additives was studied (specifically, the effect of the addition of a plasticizer and the effect of cross-linking by polyvalent ions). Based on these tests, a set of samples was selected, on which dynamic mechanical analysis, swelling and drying experiments were additionally measured. At the end of this diploma thesis, the transport properties of selected hydrogel compositions were also studied. The tests conducted in this thesis revealed that both the formation of a dual network and the addition of the mentioned additives allow us to influence the studied properties.
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