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Study of phytic acid-based organic conversion coatings on magnesium alloys
Zbíral, Roman ; Doskočil, Leoš (referee) ; Buchtík, Martin (advisor)
This thesis deals with organic conversion coatings based on phytic acid, on the magnesium alloys. In theoretical part it deals with corrosion properties of magnesium and magnesium alloys, usage of magnesium alloys for biomedicine applications. There are also summarized information’s about usage of phytic acid, it’s reactions with magnesium and magnesium alloys. At the end of theoretical part is search about phytic acid conversion coatings deposited on magnesium alloys. There are studied optimal conditions for application of phytic acid coatings such as pH, concentration, time of deposition, etc. Based on the knowledge from the theoretical part, a layer based on phytic acid was deposited on the surface of Mg alloy AZ31. The coating was evaluated in the experimental part in terms of its morphology and structure, chemical and corrosion behaviour. Scanning electron microscope (SEM) images showed the presence of microcracks in the dried coating. The chemical nature of the phytic acid-based conversion coating was investigated by energy dispersive spectroscopy (EDS) techniques in combination with Fourier transform infrared spectroscopy (FTIR). The electrochemical corrosion behaviour of Mg alloy AZ31 and coated Mg alloy was investigated by potentiodynamic polarization in Hank's solutions. Based on the obtained values of the corrosion potential and the corrosion current density, it can be stated that the applied layer of the conversion coating leads to an improvement of the corrosion properties. From the results of SEM analysis of samples after exposure in a corrosive environment, it was found that during potentiodynamic measurements no significant manifestation of corrosion attack was observed in coated samples, as was the case with Mg alloy AZ31.
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Processing and properties of porous bioceramic materials
David, Jakub ; Ručková, Jana (referee) ; Novotná, Lenka (advisor)
Bachelor thesis is focused on the study of bioceramic porous materials. The theoretical part is divided into three parts. The first part describes biomaterials, their division and use in bone tissue engineering. The second part deals with the requirements of bioceramic support systems (scaffolds). The third section describes methods for the porous structures production. The effort of the practical part was to prepare by method of direct foaming bioceramic porous materials based on calcium phosphate. It studied mainly the affect of the suspension composition on the final properties of the synthesized material. Morphology of materials was also evaluated using scanning electron microscopy. Degradability of materials in simulated body fluid was tested in terms of biological properties.
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Metal Biocompatible Materials
Stejskal, Pavel ; Němec, Karel (referee) ; Molliková, Eva (advisor)
The bachelor’s thesis deals with metal biocompatible materials, their chemical composition, heat treatment, final mechanical properties and possibilities of application of these materials. Basic terms and separation of the biocompatible materials are explained in thesis introduction. Next there are outlined a historical side and main reasons of development of these materials.
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Microstructure and mechanical properties of biodegradable magnesium alloys
Faltejsek, Petr ; Ročňáková, Ivana (referee) ; Horynová, Miroslava (advisor)
The objective of this bachelor thesis is to create a summary of materials for biomedical applications, comparison of biodegradable and biocompatible materials and also summarization of biodegradable magnesium based alloys. The thesis has four parts. The first contains a description of each group of biomaterials. The second part is focused on magnesium and its alloys, including the evaluation of individual alloys with regard to biomedical applications. The third part contains information about the types of corrosion of magnesium and its alloys and various influences on the corrosion. The last part is focused on the influence of alloying elements on the human body.
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Study of bioceramic materials for dental applications
Lokvenc, Martin ; Matoušek, Aleš (referee) ; Novotná, Lenka (advisor)
This thesis deals with bioceramics used in dentistry. The biocompatibility, which is the characteristic property of biomaterials, is described in the opening chapter of the thesis. Advantages and disadvantages of advanced ceramics are also discussed. The main attention was paid particularly to the dental bioceramics, which can be divided according to different criteria. The used classification was based on microstructure, which significantly influences behaviour and properties of biomaterials. The ceramic is viewed as a composite material, where the glass matrix is filled with different amount of crystal phase. The thesis also includes the use of the individual types of bioceramics for the manufacture of dental restorations.
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Preparation and characterization of modified polysaccharide hydrogels for medical applications
Poštulková, Hana ; Částková, Klára (referee) ; Lehocký,, Marián (referee) ; Vojtová, Lucy (advisor)
Tato dizertační práce se zaměřuje na komplexní charakterizaci přirozeně nerozpustného polysacharidu Gum Karaya (GK), aby tak přispěla k poznaní tohoto dosud málo prostudovaného biomateriálu. Kromě převádění GK do rozpustného stavu, které bylo studováno při různých podmínkách, tato práce představuje nový hydrogel založený na unikátní kombinaci materiálů polysacharidu Gum Karaya a proteinu Silk Fibroin. Tento přístup umožňuje využití specifických vlastností každého jednotlivého materiálu v daném hydrogelovém systému a také studium jejich vzájemných interakcí. Při přípravě hydrogelu nebyla použita chemická síťující činidla, příprava byla založena pouze na fyzikálním síťovaní systému. Hydrogely byly podrobeny analýze pro zjištění chemicko-fyzikálních a biologických vlastností. Studie kožních buněk keratinocytů v kontaktu s připravenými hydrogely naznačuje dobré biokompatibilní vlastnosti hydrogelů a nízkou adhezi mezi buňkami a připraveným materiálem. Dále bylo zjištěno, že GK a její směs s dalším biopolymerem vykazují bakteriostatické vlastnosti proti vybraným gram-pozitivním mikroorganismům, ale baktericidní vlastnosti nebyly pozorovány. Výsledky a pozorování získané během této práce vedou k závěru, že polysacharid Gum Karaya a z něho připravené hydrogely mají potenciál pro použití v aplikacích regenerativní medicíny, například jako hydrogely pro léčbu popálenin.
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Hydrogels and nerve tissue engineering
Šindel, Matej ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
Master’s thesis deals with hydrogels suitable for neural tissue engineering. The thesis consists of a literature research with focus on understanding the parts of the neural system, the principles of used techniques and the requirements of the neural system for materials with potential to be used in neural tissue engineering. Then the thesis continues to the experimental part, where a simple model, created from agarose with linear channel filled with collagen mass, was designed. The individual materials used in model are prepared by various methods and then are tested. Testing includes verifying their ability or inability to fulfill the required functions. Ended by evaluating their potential of further use in more complex prototypes.
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On the advanced production technology of UHMWPE joint implant part
Urbancová, Kateřina ; Sliwková, Petra (referee) ; Píška, Miroslav (advisor)
This bachelor’s thesis is dealing with the problematics of individual joint replacements. The thesis summarizes the modern materials used for making artificial joint replacements, but it concentrates mainly on the plastic femoro-tibial part of the implant, usually manufactured from ultra-high molecular weight polyethylene. This material is the best choice when manufacturing the articulating surface of the joint replacement at the moment. The thesis pays attention to the polyethylene surface treatment, as the quality of the surface affects the wear of the plastic, which is critical for the implant lifespan. The thesis also focuses on analysis of the coefficient of friction of UHMWPE in contact with the titanium femoral component. Another part of this thesis is also a wear analysis of used tibial inserts made of UHMWPE and the mechanisms of wear.
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