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Biodegradable Mg-based materials for stents and bone implants
Zemková, Mária ; Král, Robert (advisor) ; Stráská, Jitka (referee)
The bachelor thesis is focused on the effect of mechanical processing rotary swaging (RS), specifically on the microstructure, mechanical properties and corrosion properties. The investigation was performed on the magnesium alloy AE42 with a different number of RS passes, which can be useful for medical applications. RS is more efficient and cheaper alternative to different material processing methods producing fine-grained struc- ture. Fine-grain structure with grain boundaries with high angle misorientation was achieved by this process. Microstructure was inhomogeneous - the grain size decreased from the surface to the center. An improvement of mechanical properties with the increase in the number of swaging steps was observed. Processing also led to a decrease in corrosion resistance in this alloy. Microstructure development was investigated by electron microscopy scanning. Development of mechanical properties was characterized by compression deformation tests and microhardness measurements. Linear pola- rization method was used for the interpretation of corrosion resistance. 1
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Nanotechnology and biomaterials for application in cell therapy of spinal cord injury
Vaněček, Václav ; Syková, Eva (advisor) ; Smetana, Karel (referee) ; Haninec, Pavel (referee)
New approaches for the treatment of SCI use advances in the fields of nanotechnology, biomaterial science and cell therapy. The results presented in this thesis showed that superparamagnetic iron oxide nanoparticles coated with a stable dopamine-hyaluronane associate can be used for the safe and effective labeling of MSC. Cell labeling efficiency, viability and the relaxivity of the tested particles were significantly better than those obtained with the commercial particles Endorem®. The DPA-HA coated nanoparticles can be used for the noninvasive monitoring of cell therapy using MRI. Furthermore, we showed that SPION can be used for the targeted delivery of MSC to the site of a spinal cord lesion. The labeled cells can be concentrated in the lesion area by means of a magnetic implant. The process of cell targeting depends on the physical characteristics of the magnetic implant as well as on the biological features of the cells and nanoparticles, as we described with a proposed mathematical model. It is possible to modify the properties of the magnetic system, e.g. by changing the shape or size of the magnet, thus tuning the magnetic force distribution and the gradient of the magnetic field necessary for effective cell targeting. A promising therapeutic strategy for the treatment of spinal cord injury is the...
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Characterization of ultra-thin polymer films on solid substrates using different physical techniques
Pop-Georgievski, Ognen ; Rypáček, František (advisor) ; Adam, Pavel (referee) ; Werner, Carsten (referee)
The presented doctoral research was aimed at preparation and characterization of ultra thin polymer films on solid substrates using different physical techniques. Each of these physical techniques probes selectively different characteristics of the films. While some of the techniques are strong in the predetermination of some unique properties of the layers, they might be limited and give no specific/conclusive information about some other important characteristics. Therefore, only the combination of the techniques provides a profound picture of the thickness, architecture, composition and functionality of the films/layers. This combined characterization approach elucidates in details the physical characteristics and the mechanisms responsible for the unique behavior of different polymer films/layers in the application that they are intended for. In the thesis, of particular interest were films of high biomedical, biotechnological and tissue engineering importance, such as: 1. poly(lactide) films formed by grafting "from-" a silanized alacrite thin films (L605 Co-based super alloy), 2. polydopamine (PDA) films that could serve as substrate independent mod- ification platform for further surface modification steps, 3. poly(ethylene oxide)films formed by "grafting to-" PDA modified surfaces, 4....
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Silicon substituted calcium phosphate based bioceramic scaffolds
Karkuszová, Karina ; Šťastná, Eva (referee) ; Novotná, Lenka (advisor)
The theoretical part of this bachelor thesis summarizes the current state of knowledge of bioceramic materials based on calcium, phosphorus and silicon. More specifically, it focuses on calcium phosphates, the demands placed on them, the porosity of 3D foams, and biological properties such as biodegradation and bioactivity. 3D bioceramic calcium phosphate foam doped with silicon appears to be a suitable material for use in biomedical applications. It is the silicon that plays a role in the development of healthy bone and the formation of new tissue. Silicon substitutions are important in the field of investigation because they improve the bioassay of phosphate calcium. In the experimental part, calcium phosphate powders were first prepared by the hydroxyapatite and silica fusion reaction. Selected powder contents were 0; 0.1; 1, 2.5, 5, 10 and 20 wt.% SiO2. The samples were sintered at 1100 °C, 1200 °C and 1300 °C. The second part consisted in the preparation of 3D foams by direct penetration with polyurethane and the subsequent characteristics of phase composition, solubility and bioactivity. Bioceramic foams had a highly porous structure. For 42 days, sample behavior in Tris-HCl and simulated body fluid (SBF) was monitored. The results of the experiment have shown that the samples are bioactive and silicon substitution increases phosphate calcium solubility. Therefore, these materials are potentially useful for biomedical applications
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Measurement and evaluation of elongational viscosity of selected biomaterials
Šustková, Hana ; Krakovský, Ivan (advisor) ; Fortelný, Ivan (referee)
Measurement and evaluation of elongational viscosity of selected biomaterials Bachelor thesis abstract Hana Šustková 20.5.2011 This thesis analyzes the elongational viscosity of the biomaterials. The basic concepts related to the issue of measurement of shear and elongational viscosity of melts in particular focusing on the SER rheometer, which was used in the experiment, were presented. With SER rheometer elongational viscosity of BioFlex samples of BioFlex, PA6 and their mixtures at temperatures of 225o C and 235o C for ten Hencky different strain rates from 0.1 to 10 s−1 were studied. In the experiment rectangular specimens prepared for different content of Bioflex and Polyamide PA6 were used. Based on the data presented in this thesis some features of the internal structure of used bio- material, and its possible practical applications, further and qualitative changes in its properties in the mixture were described. It was shown that the linear viscoelastic response of BioFlex is two orders of magnitude below in comparison to the response of PA6 and in the temperature range the linear viscoelastic response does not change. It is shown that in mixtures with BioFlex and PA6 the BioFlex shows a signifi- cant proportion of the linear viscosity range - and at low concentrations of BioFlex in comparison to PA6...
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Metallic biomaterials
Bunganič, Pavel ; Remešová, Michaela (referee) ; Horynová, Miroslava (advisor)
In this bachelor thesis the objective was to make a summary of the basic metal-based biomaterials, which are presently used. These single materials are described and its suitability for various appliacation is evaluated depending on its chemical structure and microstructure, and its mechanical and corrosion characteristics.
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Metallic biomaterials
Bunganič, Pavel ; Remešová, Michaela (referee) ; Horynová, Miroslava (advisor)
In this bachelor thesis the objective was to make a summary of the basic metal-based biomaterials, which are presently used. These single materials are described and its suitability for various appliacation is evaluated depending on its chemical structure and microstructure, and its mechanical and corrosion characteristics.
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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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Bones implants based on Fe
Hávová, Mariana ; Vondrák, Jiří (referee) ; Sedlaříková, Marie (advisor)
This thesis refers to Fe-based biodegradable materials and their potencial aplications in medicine, especially as temporary bone implants. This work generaly summaries aplications of biomaterial in medicine with more interest kept on biodegradable materials and their in-vivo corrosion. The experimental part refers to conduction of porous Fe-based materials with silica addition. The structure of prepared specimens is identified by EDX and XRD analysis. The imersion test and electrochemical studies were conducted to observe corrosion behaviour with respect to different concentration of silica. Potenciodynamic curves were obtained to determine corrosion potencial and corrosion current density of prepared samples.
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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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