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Materials for biodegradable bones based on Fe
Hrabovský, Jan ; Vondrák, Jiří (referee) ; Sedlaříková, Marie (advisor)
The thesis deals with biodegradable bone implants which must have good mechanical properties and also good compatibility with the human body. The thesis contains literary research in the area of bone physiology, biogenic materials and implants for the human body. The thesis focues on the selection of suitable materials for biogenic implants. It is also described the preparation of iron powder mixtures and application onto selected materials. The selected samples were subjected to thermal analysis.
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Bone implants based on Fe
Bachmayer, Marek ; Vondrák, Jiří (referee) ; Sedlaříková, Marie (advisor)
This thesis deals with usage of metal materials in bone implats creation process. This work also includes information about structure and attributes of bones, body fluids and content of iron in human organism. Following part of the paper deals with osteosynthesis, therefore commonly used methods of treating bone defects. Next part of this bachelor’s thesis is discussing the issue of biomaterials, biocompatibility and biodegradability of metal materials. Sample preparion procedure and description of samples, electrochemical corrosion and microscopic observation is included altogether with a pictorial documentation at the last chapters of this paper.
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Biodegradable bones implants based on iron
Hrabovský, Jan ; Zatloukal, Miroslav (referee) ; Sedlaříková, Marie (advisor)
This work deals with a current topic, which are biodegradable bone implants. These implants seem to be a suitable candidate for temporary fixations, with their gradual decomposition. An important parameter is not only the mechanical properties so that the material can withstand the load, but above all the corrosion properties and the degradation process. This work introduces the physiology of bone, trace elements and also describes current trends in the field of implants. The last part is a theoretical introduction to cross-stage processes. The practical part is focused on the preparation of iron-based samples with various dopants, subsequent annealing and analysis.
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Solubility control of biodegradable starch-based packaging
Krobot, Štěpán ; Ondreáš, František (referee) ; Lepcio, Petr (advisor)
This bachelor thesis deals with the preparation and testing of biodegradable films based on starch. The aim of the thesis is laboratory preparation of foils based on various types of starch, glycerol, polyvinylalcohol and with the addition of plasticizer – citric acid. Four different types of starch and two types of polyvinyl alcohol were used. In the first series of samples, the ratio of added glycerol to starch content was varied. Samples in the second series were prepared in the same ratios, but with different PVA. A citric acid solution was added into the last series of samples. The second aim of the thesis, after pressing the films, was to determine their solubility and stability in aqueous media depending on the ratio between added glycerol to starch content, the type of polyvinylalcohol used, and the addition of citric acid to the mixture. It has been found that citric acid appears to affect the chemical structure of the films and thus their solubility in aqueous media as well as their mechanical properties. Fourier-transform infrared spectroscopy (FTIR) was used to study the structure of the films and to elucidate its effect on solubility.
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Assessment of the effect of formaldehyde resin monomers on the environment
Kalčíková, Gabriela ; Doležalová Weissmannová, Helena (referee) ; Zlámalová Gargošová, Helena (advisor)
Thousand of new substances with unknown environmental effect are produced and used daily. Many of them are deliberately or by negligence released and deposited into the environment where they could undergo different transport and degradation mechanisms. They are able to affect different types of organisms, as well as humans. For this reason, the awareness of the problems, associated with pollution of all environmental compartments is growing. The environmental impact of monomer formaldehyde resins, which are produced for commercial use, on the environment were studied in this research. For the purposes of ecotoxicological evaluation samples of melamine-formaldehyde and urea-formaldehyde resin were chosen and three toxicity tests were run: acute test with measurement of inhibition of the mobility of Daphnia magna, the acute test with luminescent bacteria Vibrio fischeri and acute test with measurement of inhibition of oxygen consumption by activated sludge. For more comprehensive assessment of the impact of these substances on the environment, biodegradability was also determined. Both tested substances showed minor hazardous impact to testing organisms and it can be concluded, that these substances should not present a significant risk to the environment.
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Properties of biocomposites based on flax fibers
Pelánová, Markéta ; Obruča, Stanislav (referee) ; Přikryl, Radek (advisor)
This thesis is focused on composites, which are composed of degradable components. The theoretical part deals with composite materials, treatment of fibers and properties of composites. The purpose of this study is to create a composite consisting of polyhydroxybutyrate, which is reinforced with flax fibers with various modifications. The thesis also evaluates the effect of reinforcing fibers in the composite material on the tensile properties and hydrolytic stability and degradability of the composite in compost in laboratory conditions.
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The effect of polymer microfibers on rheological and mechanical properties of calcium phosphate bone cements
Dzurov, Matej ; Montufar Jimenez, Edgar Benjamin (referee) ; Vojtová, Lucy (advisor)
Táto diplomová práca sa zaoberá mechanickými a reologickými vlastnosťami resorbovateľného polymér-fosforečnanového kompozitu na báze kostného cementu vystuženého mikrovláknami z PCL (poly(-kaprolaktón)) a Pluronic-om modifikovanými PCL vláknami. Teoretická časť popisuje štruktúru kostí, vývoj kostných cementov a štrukturálne prídavky (aditíva). V experimentálnej časti je rozoberaná syntéza a charakterizácia PLGA-PEG-PLGA termosenzitívneho kopolyméru a - modifikácie fosforečnanu vápenatého ako aj technika prípravy mikrovláken. Roztok kopolyméru bol použitý pre zlepšenie obmedzenej injektovateľnosti pasty s pomerom kvapalnej k práškovej fáze (L/P) 0,5 ml/g pre všetky vzorky. Dve rôzne techniky zamiešania pasty boli použité pre možnosť kontrolovania porozity pripraveného cementu. PCL a PCL-Pluronic vlákna využité ako výstuž boli testované v troch rôznych prídavkoch, a to 1, 3 a 5 hmotnostných percent vláken na celkovú hmotnosť pripravenej pasty. Pripravené pasty boli testované pomocou dynamickej reologickéj analýzy na reometri pri laboratórnej teplote (23 °C) a fyzologických podmienkach (37 °C) so zámerom stanoviť spracovateľnosť a tuhnutie pasty. Vzorkám na ostatok analýz bolo umožnené vytvrdzovanie pri fyziologických podmienkach po dobu 10 dní. Po vytvrdení boli testované mechanické parametre ako sú pevnosť v tlaku, Youngov modul pružnosti a pevnosť v ťahu v priemere vysušených a v niektorých prípadoch aj hydratovaných vzoriek. Porozita vzoriek bola stanovená pomocou Roentgénovej počítačovej mikro-tomografie. Rastrovacia elektrónová mikroskopia bola využitá na študovanie mikroštruktúry a zabudovanie vláken do keramickej matrice. Prítomnosť vláken bola semi-kvantitatívne stanovená pomocou Fourier transformovanej infračervenej spektroskopie. Difrakcia Roentgénového žiarenia poskytla údaje o fázovom prechode prášku a jeho mineralogickom zložení. Jednotlivé hodnoty, obdržané z jednotlivých analýz, boli medzi sebou porovnané a adekvátne diskutované. Výsledkom práce je potvrdenie mierneho zlepšenia pevnosti v tlaku vzoriek vystužených hydrofóbnymi PCL alebo amfifilnými PCL-Pluronic vláknami pričom, PCL-Pluronic vlákna poskytli lepšie výsledky. Preto bolo usúdené, že polymér-fosforečnanový kostný cement vystužený vláknami je nádejným kandidátom na uplatnenie v chirurgickej praxi.
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Polymeric nanoparticles for poorly water soluble drugs delivery
Nekolová, Martina ; Holas, Ondřej (advisor) ; Smékalová, Monika (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Mentor: PharmDr. Ondřej Holas, Ph.D. Student: Martina Nekolová Title of thesis: Polymeric nanoparticles for poorly water-soluble drugs delivery Polymeric nanoparticles represent a modern drug form. One of the main advantages is influencing the pharmacokinetic properties of the administered substance - e.g. increasing solubility in water. They enable the targeted delivery of the drug to the affected tissue and this way minimize adverse effects. This could be of great benefit to the therapy of cancer or inflammatory diseases. Both the target tissue and the nanoparticles must have some specific properties. For particles, it is, for example, size and surface charge. The aim of this work was to prepare nanoparticles with a substance poorly soluble in water, represented by curcumin. The particles were prepared by the nanoprecipitation method with different types of poly(lactic-co-glycolic acid) (PLGA) copolymer. A 50:50 linear PLGA polymer and a branched PLGA A2 polymer were used. The prepared nanoparticles were compared on several parameters - particle size and polydispersity, encapsulation efficiency (EE), drug-loading capacity (DLC) and dissolution profile. PLGA 50:50 was found to provide...
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Návrh nábytkového prvku s využitím materiálu z houbového mycelia
Paulasová, Dominika
The thesis deals with the options for using fungal mycelium in the field of furniture. The aim was to design a furniture element so that the material’s prope-rties are taken into account. The theoretical part provides information on the ma-terial, its production, properties and processing possibilities. The literature re-view gives an insight into the current development of mycelium materials and the options for their use. The practical part deals with the design of a bench whose seat is made of mycelium composite. The experimental part thus includes mea-surements of selected material characteristics such as impact resistance, Brinell scale hardness, density profile, flakiness and flexure. The measurements compare samples with different input parameters such as the time the mycelium grew and initial densification during moulding.
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Preparation and evaluation of nanoparticles for targeted treatment of inflammatory diseases
Wurzel, Natalie ; Holas, Ondřej (advisor) ; Smékalová, Monika (referee)
Charles University, Faculty of Pharmacy in Hradci Králové Department of Pharmaceutical Technology Supervisor: PharmDr. Ondřej Holas, PhD Consultant: Mgr. Barbora Boltnarová Student: Natalie Wurzel Title of Thesis: Preparation and evaluation of nanoparticles for targeted treatment of inflammatory diseases Nanoparticles are used in the health sciences for, among other things, targeted drug delivery. This is used for the therapy of cancer and chronic inflammatory diseases. The aim of this diploma thesis was to prepare nanoparticles suitable for targeted treatment of inflammatory diseases. The task was to determine the ideal concentration of the active substance, which would ensure high encapsulation efficiency and drug loading. The difference between nanoparticles prepared from PLGA 5/5E and PLGA 7/3A was also investigated. Nanoparticles were prepared by the nanoprecipitation method. The matrix of the nanoparticles was composed of PLGA with different ratios of lactic acid and glycolic acid. Acetone was used as the organic solvent. The encapsulated active substance was the anti-inflammatory dexamethasone acetate. The aqueous phase was consisted of a 0.1% aqueous solution of Pluronic F-127. The evaluated parameters of the resulting nanoparticles included size, polydispersity index, zeta potential,...
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