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Preparation and Characterization of Magnetic Carriers from Hypercrosslinked Polystyrene Microspheres and their Application in a Biosensor.
Šálek, Petr ; Šňupárek, Jaromír (referee) ; Šafařík,, Ivo (referee) ; Horák, Daniel (advisor)
With the aim to develop and characterize a functionalized highly magnetic polymer carrier of micrometer size and of a narrow particle size distribution that will be suitable for biological application, hypercrosslinked microspheres were prepared. Simultaneously, the relation between structure and properties of product was observed. Condition of dispersion polymerization were optimized to obtain starting monodisperse poly(styrene-co-divinylbenzene) [P(St-DVB)] microspheres. The P(St-DVB) microspheres of different degree of crosslinking were prepared and effect of some polymerization parameters such as type of solvent, initiator, concentration and mode of DVB addition on morphology, size and particle size distribution were investigated. The starting microspheres were hypercrosslinked to obtain microporous inner structure. Hyperosslinked particles had very large specific surface area (> 1000 m2/g) and a high content of micropores (ca. 0.6 ml/g). First, P(St-DVB) microspheres were chloromethylated using three different chloromethylation agents to regulate their porous properties. Hypercrosslinking was achieved by the addition of stannic chloride as a catalyst and by increasing a temperature. The hypercrosslinked microspheres were then functionalized with sulfo- or aminogroups. The functional groups captured precipitated iron oxide inside the porous structure of the microspheres and also served as a reactive site for intended immobilization of the protein. A solution of ferrous and ferric chloride was imbibed under vacuum into the porous structure and the iron oxide was precipitated by an aqueous ammonia solution. Finally, the magnetic functionalized hypercrosslinked micropsheres were integrated into a biosensor for qualitative detection of ovalbumin.
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Probiotics and prebiotics - a study of interactions, effects and co-encapsulation
Vrtná, Monika ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
This diploma thesis is focused on encapsulation probiotics and co-encapsulation with some types of prebiotics. In theoretical part is aimed to probiotics, their general characteristics and application of probiotics in food industry. There are described prebiotics and their classification, there is described principles of encapsulation and encapsulation techniques. Methods, which are used for analysis of particles and encapsulation components were introduced too. The experimental part describes methods of prebiotics characterization by high performance liquid chromatography, thin layer chromatography and spectrophotometric methods. Cultivation of probiotics with prebiotics - hydrolyzed and non-hydrolyzed wad tested. Using flow cytometry cell viability was measured too. Finally probiotics and prebiotics were encapsulated, mainly by encapsulator machine. Long-term stability of particles during 6 week storage was observed. The particles were exposed to effect of artificial intestinal, gastric and bile juices.
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Device for magnetic mixing of solution containing magnetizable particles
Zítka, Jan ; Martiš, Jan (referee) ; Červinka, Dalibor (advisor)
The aim of this works was the design and construction of a device that will be used for magnetizable beads mixing without application of mechanical force. In theoretical part of this work, properties of ferromagnetic nano- and microbeads and methods used for mixing of these beads were described. Two coils were reeled in for the device, each consisting of 200 turns and with 0.8 . The device construction was designed in program CAD. Different parts of the instrument were 3D printed. The control program, which enables changes in coil switching, was created and then the testing of device functionality was performed.
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Encapsulation of lactic acid bacteria
Vrtná, Monika ; Lichnová, Andrea (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on encapsulation of two strains of probiotic bacteria. Lactic acid bacteria were encapsulated into several types of materials, mostly polysaccharides. The theoretical part describes the techniques of encapsulation applicable in the food industry. During the experimental part alginate and chitosan microparticles were prepared. These particles exhibited different sizes and some of them were modified by starch and carboxymethyl cellulose. Particles were used for encapsulation of two strains - Bifidobacterium breve and Lactobacillus acidophilus. Using flow cytometry cell viability was measured after 24-hours cultivation of bacteria. Particles were observed immediately after encapsulation by optical microscopy and then long-term stability in model foods was evaluated after two days, a week and after four weeks of incubation. Using the Bürker chamber the alived and death bacteria were counted inside and outside the capsule. The stability and viability of the cells were studied also in the artificial intestinal, stomach and bile juices. As the best material for encapsulation of lactic acid bacteria 2% alginate modified by carboxymethyl cellulose was found. The highest viability of bacteria was observed in milk as the real model food. Prepared particles are suitable for use in the food industry.
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Využívání dlouhodobého uvolňování léčiv v reprodukci ryb
KNOWLES, Jindřiška
The PhD thesis was aimed to develop and validate an innovative method of hormone stimulation using PLGA microparticles for sustained release of a synthetic analogue of mammalian gonadotropin-releasing hormone in several economically important fish species. Since this is the first record of the use of PLGA microparticles in fish, the focus was to establish the optimal dose of the active substance, quantify the steroid response of the broodstock, and to assess the quality and quantity of obtained sex products. The theoretical part of the thesis was focused on elaborating a study reviewing methods of hormonal treatment in fish, and discuss the potential of PLGA microparticles in fish reproduction. While, the experimental part of the work was focused on evaluation of the effect of PLGA microparticles in those fish species commonly reared in intensive and pond aquaculture. Fish of both sexes were included to determine the effect of the treatment on the production and quality of eggs as well as on the quality and quantity of sperm.
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Micronization of biopolymer material
Gistingerová, Radka ; Wikarská, Monika (referee) ; Pospíšilová, Aneta (advisor)
This bachelor thesis focuses on the preparation of poly(3-hydroxybutyrate) microparticles for cosmetic products. The particles were prepared by emulsion technology, where a chloroform solution of poly(3-hydroxybutyrate) was dispersed in an aqueous solution of polyvinyl alcohol. The original poly(3-hydroxybutyrate) was also in powder form, but it was thought that its properties could be improved by this treatment. Evaporation of all the chloroform produced poly(3-hydroxybutyrate) particles. By changing the input concentrations of the two components, the particle size distribution was altered. All prepared powders were measured using a scanning electron microscope and measured by laser diffraction. Experiments and subsequent measurements showed that increasing the concentration of the emulsifier solution leads to an overall decrease in particle size, whereas a higher concentration of poly(3-hydroxybutyrate) causes an increase in particle size. To evaluate the potential of the prepared particles in cosmetics, all powders were evaluated sensorially. The evaluators observed almost no differences between the powders, only the original poly(3-hydroxybutyrate) powder was rated slightly worse compared to our prepared powders. The powder that is currently used in cosmetic products was rated very similarly to the powders that were prepared by emulsion technology.
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Preparation and characterization of nanoparticles with encapsulated antimicrobial component
Dohnalová, Marie ; Strečanská, Paulína (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on the preparation and characterization of particles with encapsulated natural substances with antioxidant and antimicrobial properties. Selected antioxidants were anthocyanins, eugenol and vitamin E, as one of the most powerful antioxidants. At the same time, antimicrobial agents were chosen, in this case eugenol. In the theoretical part, individual active substances, materials for the preparation of particles, methods of their preparation were characterized and the principle of determining the safety of used materials. In the experimental part, selected active substances were characterized and the preparation of particles was optimized. Two types of liposomes were prepared, for which the encapsulation efficiency, size and stability were determined. Also prepared aqueous extracts of blueberries and blackberries were prepared, for which total anthocyanin content has been determined. The extracted substances from the plant material were encapsulated into alginate particles. Furthermore, the gradual release of active substances from particles into model environments using a spectrophotometer was determined. During the gradual release of active substances from the particles, the antioxidant effect was also monitored, in which it was possible to observe a decrease with the passage of time. The antimicrobial effect of active substances and liposomes against model microorganisms Escherichia coli and Micrococcus luteus was also tested. Cytotoxicity tests on human keratinocytes were performed on selected active substances, extracts and prepared nanoparticles, where it was proven that the selected materials are non-cytotoxic. Finally, a proposal for a possible application form in the form of an alginate hydrogel was created.
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Preparation of pharmaceutical formulations based on polymeric and lipid carriers
Kubačková, Jana ; Zbytovská, Jarmila (advisor) ; Panáček, Aleš (referee) ; Štěpánek, František (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate Mgr. Jana Kubačková Supervisor Assoc. Prof. Jarmila Zbytovská, Mgr., Dr. rer. nat. Co-supervisor PharmDr. Ondřej Holas, PhD. Title of Doctoral Thesis Preparation of pharmaceutical formulations based on polymeric and lipid carriers Nanomedicine allows application of nanoscaled drug delivery carriers to achieve a therapy that can be tailored in terms of e.g. controlled release, site-specific delivery and protection of an active substance. From multiple nanoplatforms available for drug delivery, advantage was taken of biocompatible and biodegradable polymers and lipids to enable targeted intracellular delivery, delivery of a poorly water-soluble drug and delivery of a sensitive macromolecule. In the study with biodegradable polymeric nanomaterial we worked with experimental poly(lactic-co-glycolic acid) (PLGA) polymers. The formulations were optimised for targeting to phagocytic macrophages - of size up to 300 nm and negative surface charge. For this purpose, two linear and one branched PLGA were screened in combination with one of four surfactants in low concentrations (0.1-1%). These PLGA polymers were formulated into nanoparticles and loaded with a hydrophilic fluorescent dye Rhodamine B...
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Preparation of pharmaceutical formulations based on polymeric and lipid carriers
Kubačková, Jana ; Zbytovská, Jarmila (advisor) ; Panáček, Aleš (referee) ; Štěpánek, František (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate Mgr. Jana Kubačková Supervisor Assoc. Prof. Jarmila Zbytovská, Mgr., Dr. rer. nat. Co-supervisor PharmDr. Ondřej Holas, PhD. Title of Doctoral Thesis Preparation of pharmaceutical formulations based on polymeric and lipid carriers Nanomedicine allows application of nanoscaled drug delivery carriers to achieve a therapy that can be tailored in terms of e.g. controlled release, site-specific delivery and protection of an active substance. From multiple nanoplatforms available for drug delivery, advantage was taken of biocompatible and biodegradable polymers and lipids to enable targeted intracellular delivery, delivery of a poorly water-soluble drug and delivery of a sensitive macromolecule. In the study with biodegradable polymeric nanomaterial we worked with experimental poly(lactic-co-glycolic acid) (PLGA) polymers. The formulations were optimised for targeting to phagocytic macrophages - of size up to 300 nm and negative surface charge. For this purpose, two linear and one branched PLGA were screened in combination with one of four surfactants in low concentrations (0.1-1%). These PLGA polymers were formulated into nanoparticles and loaded with a hydrophilic fluorescent dye Rhodamine B...
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