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Study of stability of antimicrobial nanomaterials in different environment by HPLC
Janderová, Šárka ; Trachtová, Štěpánka (referee) ; Márová, Ivana (advisor)
This thesis deals with the preparation of nanomaterials (nanoparticles, nanofibers) with encapsulated active substances and the stability of these nanomaterials in different environments using liquid chromatography. The development and optimization of methods for monitoring the kinetics of release of encapsulated substances from nanomaterials into various environments play a key role in research aimed at their utilization in the pharmaceutical, food, and cosmetic industries, and also contribute to the development of new antimicrobial nanomaterials limiting antibiotic resistance. The theoretical part focuses on the characterization of nanomaterials (nanoparticles, liposomes, nanofibers, and combined nanomaterials). Another section of the literature review deals with natural (eugenol, carvacrol, curcumin, thymol, vitamin E) and synthetic (ampicillin, streptomycin) antimicrobial substances. The final chapter discusses the instrumental methods used for the characterization of nanomaterials and the evaluation of their stability, released, and degradation products. In the practical part, the antioxidant activity of selected substances was first monitored. Liposomes were prepared, and their stability and encapsulation efficiency were examined. An HPLC method for determining active substances was optimized. Subsequently, the gradual release of the mentioned active substances from prepared liposomes was monitored. Nanofibers were prepared using forcespinning, and their release into selected model environments was also analyzed. Distilled water with minimal ion and impurity content served as a model environment, as well as a physiological solution at 25°C, simulating the temperature of the human body surface, and a physiological solution at 37°C, characteristic of human body temperature. This analysis provides a comprehensive view of the behavior of prepared materials and their potential practical applications. In the final section, combined nanomaterials (based on nanofibers and nanoparticles) with encapsulated active substances were prepared. The gradual release of active substances and any potential synergistic effects were examined for these nanomaterials.
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Characterization of cytotoxic effect of combined antimicrobial nanomaterials
Kozlíčková, Hana ; Fialová, Lenka (referee) ; Márová, Ivana (advisor)
This thesis deals with the study of the effects of combined nanomaterials on human skin cells. Pure antimicrobial substances, two types of liposomes enriched with antimicrobial substances, nanofibers with antimicrobial substances and, finally, four types of combined nanomaterials were analyzed from the point of view of cytotoxicity. The analysed active substances were eugenol, thymol, cavarcrol, curcumin, vitamin E and the antibiotics streptomycin and ampicillin. In the theoretical part of the work, the cell line of human keratinocytes, used in the experimental part of the work for cell tests, was characterized. Furthermore, individual active substances with an antimicrobial effect were described and the principles of biological effects were described, which include antimicrobial, antioxidant, cytotoxic and synergistic effects. Additionally, the theoretical part described individual nanomaterials, their preparation and usage in cosmetics and medicine. The experimental part was based on the characterization of prepared nanomaterials and on testing the influence of individual antimicrobial substances on the proliferation and viability of human HaCaT cells. Using the DLS method, the size of the prepared liposomes was measured and the effect of PHB and the type of active substance on their size was studied. MTT and LDH tests were chosen to test the cytotoxicity of individual substances. Furthermore, a scratch test was performed to monitor the effect of the investigated substances on proliferation and the rate of wound healing by cells. The last performed tests were immune response assays, in which were tested the samples for production of the human anti-inflammatory cytokines IL-6 and IL-8. In experimental part of this thesis, it was found that the prepared nanofibrous materials are safe for use in healthcare or cosmetics and, in the future, suitable to produce nanofibrous wound coverings enriched with antimicrobial substances, which can give them exceptional properties.
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Preparation and characterization of nanofiber wound dressings
Jiroušková, Pavla ; Uhlířová, Renata (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis deals with the preparation and characterization of nanofiber wound dressings. The materials used for the preparation of nanofibers were poly(3-hydroxybutyrate) and gelatin. Active substances, such as ampicillin and ibuprofen, were incorporated into the wound dressings. In the theoretical part of the work skin, wound healing, and nanofibers and their properties were described. This part also deals with the use of nanofibers as wound dressings. Additionally, it depicts materials suitable for the preparation of nanofiber wound dressings. Furthermore, this section contains a review focused on various methods of preparation of nanofibers, drugs that can be incorporated into the fibers and the subsequent determination of the safety of the prepared dressings. In the experimental part, nanofiber wound dressings containing ampicillin and ibuprofen were produced. The maximum possible amount of active substance feasible to be incorporated into the nanofibers has been determined. Subsequently, combined wound dressings were prepared to study the release rate of active substances into the model environments. The release in the time intervals was determined spectrophotometrically. Finally, antimicrobial activity assays were performed to test the effect of dressings containing ampicillin on selected strains of microbiirganism: S. Epidermidis, E. Coli and M. Luteus
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Carbon nanoparticles from South Moravian lignite
Drozdová, Miroslava ; Enev, Vojtěch (referee) ; Pekař, Miloslav (advisor)
This bachelor thesis deals with the issue of isolation of carbon nanoparticles from lignite, which seems to be their cheap source. The aim of this work is to elaborate a research on the use of coal matrices as a source of carbon nanoparticles and also to design and perform further experiments testing the usability of South Moravian lignite. Based on the literature search, a simple mechanochemical procedure was proposed to obtain carbon nanoparticles from lignite. The lignite was mechanically stressed by the ultrasonic disintegrator with simultaneous action of water or hydrogen peroxide. Lignite has been able to isolate particles fluorescing in the blue visible light, but the process will need to be further modified. However, South Moravian lignite could be a source of carbon nanoparticles.
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Development and preparation of antimcrobial nanostructure biomaterials
Drabíková, Nela ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
The presented diploma thesis deals with the optimalisation of preparation and the preparation of combined nanostructured antimicrobial biomaterials itself. In the theoretical part, a review focused on used materials and consequently preparation of nanoparticles and nanofibers was elaborated. Furthermore, the used antimicrobial substances – curcumin and ampicillin, and the principle of cytotoxicity assay were described.In practical part the optimalisation process is described. Furthermore the safety of prepared materials and used antimicrobial substances on HaCaT cell line was tested, in order to confirm their possible further use in cosmetic and pharmaceutical industry. Great part of the thesis deals with evaluation of the antimicrobial activity of used substances and prepared combined nanomaterials on multiple microorganisms from grampositive bacteria, gramnegative bacteria and yeasts. Also the release speed of antimicrobial substances from prepared nanomaterials was determined by spectrophotometer. The amount of released ampicillin from prepared nanomaterials was determined by liquid chromatography.
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Automatisation of an experimental setup for optical spectroscopy
Hrabina, Jakub ; Gallina, Pavel (referee) ; Dvořák, Petr (advisor)
This bachelor thesis deals with the development and description of an application that enabled full automation of an experimental assembly for spectral mapping using confocal optical microscopy. It presents communication with all individual devices and explains the principle of data collection from the examined sample and their subsequent mathematical processing. The output of this application is the visualization of 2D spectral maps evaluating the intensity and position of spectral peaks, with the possibility of exporting user-friendly point spectra. In addition, the work further describes a research study of optical confocal spectroscopy with applications to nanophotonics. In addition, the functionality of the whole application is demonstrated on the spectral response of a 2D metasurface, which acts as a Bayer mask.
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Nanotechnology utilization in nuclear industry and research
Skalička, Jiří ; Štefánik, Milan (referee) ; Katovský, Karel (advisor)
This thesis introduces reader to current knowledge of nanomaterials and their usage. It summarises production methods and usage of different materials in nuclear power plants, nuclear research and nuclear medicine. Theoretical part of this thesis is dedicated to possible usage of carbon nanotubes for neutron beam collimation and guides. In experimental part different materials were tested in measuring box connected to horizontal radial channel of VR-1 nuclear reactor and their influence on neutron flux was measured. Tested samples were non-oriented carbon nanotubes, carbon nanofibers, alumina nanowires, oriented carbon nanotubes with several angles of rotation and these samples were compared with results of graphite.
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Flexible generators of electrical energy
Tesařová, Tereza ; Holcman, Vladimír (referee) ; Tofel, Pavel (advisor)
This bachelor thesis is focused on actual research part of energy harvesting technologies – flexible electrical generators, which mean the special generating of electricity using specific flexible materials. The net charge result is affected by the incidental mechanism to transform certain energy form into electrical power and is influenced of material range, which determines what will be harnessed as a source of energy. The energy harvesting is aiming at producing alternative and efficient ways instead of harmful and strained manufacture processing.
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Vliv proteinové korony na toxicitu částic
Jemelíková, Vendula
When foreign particles enter the organism, they come into contact with the physiological environment and subsequent adsorption of naturally occurring biomolecules on the surface of the particles. Protein corona is formed during the adsorption of proteins, which fundamentally changes the physico-chemical properties of the particles. The aim of this work was to focus on the change in properties and toxicity of particles caused by the formation of a protein corona around selected particles. The formation of protein corona around different particles based on hydroxyapatites (CaNPs), iron (FeNPs), platinum (PtNPs) and titanium (TiNPs), was characterized and proved using electrophoretic methods, and subsequently the change in size, zeta potential and cytotoxicity was monitored depending on the formation of a protein corona. Based on the results, it is possible to claim that in all cases particles with a protein corona were less toxic to breast tumor cells, than particles without a corona and CaNPs were the most cytotoxic. In general, it is possible to say that the formation of protein corona around the tested nanoparticles affects their properties and reduces cytotoxicity and oxidative stress.
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Combined preparatives with encapsulated antimicrobial component
Kneblová, Kateřina ; Bendová, Agáta (referee) ; Márová, Ivana (advisor)
The presented bachelor thesis deals with the preparation and characterization of liposome nanoparticles that have been functionalized by the active substance and subsequently tested for their synergistic effect against microorganisms. In the theoretical part, a research focused on an overview of antimicrobials agents and on encapsulation techniques. In the experimental part, the method of sonification was used to prepare liposomes. Natural and synthetic antimicrobial substances were encapsulated into the particles. The size, stability, encapsulation efficiency, antioxidant and antimicrobial activity were determined for the liposomes that were prepared. Antimicrobial activity was tested on the gram-negative strain Esterichia coli, the gram-positive bacteria Micrococcus luteus, and one fungual strains Candida glabrata. Subsequently, a synergistic effect of the active substances was observed, which was demonstrated both when combining a synthetic active substance with a natural one and when combining two natural active substances. The synergistic effect of the encapsulated substances was observed after a longer period of time than that of the synergy of the pure active substrances. Which could find its application in the pharmaceutical industry, in drug delivery, or in the food industry in preservation processes.
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