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Development and characterization of hydrogel carriers for modern agricultural applications
Mai, Thuy Ha ; Kalina, Michal (referee) ; Sedláček, Petr (advisor)
The bachelor thesis is focused on characterization of hydrogel carriers and their application in agriculture. Entrapment of active phase within the hydrogel matrix would allow release of its content in controlled rate. The theoretical part describes encapsulation techniques and suitable biocompatible materials involved in encapsulation. For the experimental part, the release of soil bacteria Cupriavidus necator H16 from alginate matrix was examined. The focus was on the release rate of bacteria via diffusion and later, on the release rate of bacteria encouraged by chemical or enzymatic reagents. Further modification of carrier was suggested by adding hydrophobic barrier composed of polyhydroxybutyrate (PHB). The modified alginate beads seemed to be more resistant toward enzymatic or chemical agents, thus the process of the release was to some extent suppressed. This fact might suggest PHB as a possible vessel for optimization of controlled release system of hydrogel carriers.
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Preparation and characterization of hydrogel delivery systems from poly-gamma-glutamic acid
Mai, Thuy Ha ; Smilek, Jiří (referee) ; Sedláček, Petr (advisor)
The presented diploma thesis focuses on the development and preparation of model poly--glutamic acid based hydrogel carrier systems. For the hydrogel carrier preparation, methods based on physical interactions between polyelectrolyte and oppositely charged multivalent ion or oppositely charged macromolecule were proposed. Based on the pilot experiments, trivalent iron cation and chitosan were selected as suitable crosslinking agents. By crosslinking -PGA via ferric cations a successful bead formation has been accomplished and attempts have been made for a preparation of beads smaller than 1 000 m by employing microencapsulation techniques. Rapid disintegration of -PGA beads occurred upon immersion of the beads in water making these systems unsuitable for drug carrier applications. Interactions between -PGA and chitosan lead to polyelectrolyte complexes formation and by optimizing concentrations and pH of polyelectrolyte solutions, a formation of homogenous looking hydrogel with high water content (>0,9) has been achieved.
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Preparation and characterization of hydrogel delivery systems from poly-gamma-glutamic acid
Mai, Thuy Ha ; Smilek, Jiří (referee) ; Sedláček, Petr (advisor)
The presented diploma thesis focuses on the development and preparation of model poly--glutamic acid based hydrogel carrier systems. For the hydrogel carrier preparation, methods based on physical interactions between polyelectrolyte and oppositely charged multivalent ion or oppositely charged macromolecule were proposed. Based on the pilot experiments, trivalent iron cation and chitosan were selected as suitable crosslinking agents. By crosslinking -PGA via ferric cations a successful bead formation has been accomplished and attempts have been made for a preparation of beads smaller than 1 000 m by employing microencapsulation techniques. Rapid disintegration of -PGA beads occurred upon immersion of the beads in water making these systems unsuitable for drug carrier applications. Interactions between -PGA and chitosan lead to polyelectrolyte complexes formation and by optimizing concentrations and pH of polyelectrolyte solutions, a formation of homogenous looking hydrogel with high water content (>0,9) has been achieved.
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Development and characterization of hydrogel carriers for modern agricultural applications
Mai, Thuy Ha ; Kalina, Michal (referee) ; Sedláček, Petr (advisor)
The bachelor thesis is focused on characterization of hydrogel carriers and their application in agriculture. Entrapment of active phase within the hydrogel matrix would allow release of its content in controlled rate. The theoretical part describes encapsulation techniques and suitable biocompatible materials involved in encapsulation. For the experimental part, the release of soil bacteria Cupriavidus necator H16 from alginate matrix was examined. The focus was on the release rate of bacteria via diffusion and later, on the release rate of bacteria encouraged by chemical or enzymatic reagents. Further modification of carrier was suggested by adding hydrophobic barrier composed of polyhydroxybutyrate (PHB). The modified alginate beads seemed to be more resistant toward enzymatic or chemical agents, thus the process of the release was to some extent suppressed. This fact might suggest PHB as a possible vessel for optimization of controlled release system of hydrogel carriers.
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