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Stents and their applications in medicine
Sokl, Antonín ; Němec, Karel (referee) ; Molliková, Eva (advisor)
The aim of this bachelor thesis, which deals with types of stents and their use in medical area, is the provision od detailed reserches of the most frequently used biomaterials, namely details of metals, ceramics, polymers and composites, considering the suitability of their use for the production of substitutes for particular human body structures. The introductory chapters are devoted to external and internal fixation for fractures, dental implants and replacement of renal function. The following chapters deals with stents and their possible variations, especially the chapters are about esophageal stents, prostatic stents and ureteral stents. The final part of this thesis contains a detailed definition of coronary stents, their functional and shape modifications.
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Materials in medicine practice
Dvořáková, Tereza ; Čikl, Josef (referee) ; Molliková, Eva (advisor)
This bachelor's thesis deals with literary research on metal, ceramic and polymer materials for medical applications. The history of these materials, their properties and material requirements are described in the first part. Further, the most often application areas of fixators and soft or hard tissue replacements are introduced. This thesis is ended by introducing a perspective science filed, which is a tissue engineering.
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Synthesis of bioactive glass for medical application
Wiederová, Kristýna ; Galvánková, Lucie (referee) ; Bartoníčková, Eva (advisor)
In this bachelor’s thesis, the 45S5 bioactive glass was synthesized via sol-gel method. Alternative precursors as colloidal silicas as a silicon source and phosphorous acid, ammonium hydrogenphosphate and ALUFOS were used. Three dierent gel ageing procedures were tested. The nine dierent samples were synthesized and analyzed. The dependence of the fnal properties of the products on the type of precursors has been confrmed. The dependence on the preparation process has not been confrmed within this thesis.
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Biocompatibility and immunocompatibility of polymers for gene therapy
Matyášová, Veronika ; Šírová, Milada (advisor) ; Tučková, Ludmila (referee)
Gene therapy is a potential strategy for treatment of diseases caused by a gene defect. Recent studies are involved particulary in the cure of diseases caused by single gene defect (cystic fibrosis, haemophilia, muscular dystrophy etc.). Our work is part of a project aiming at developing ex vivo non-viral gene delivery systems that could be used for the treatment of ocular and cardiovascular diseases. The gene vectors are biodegradable polymeric carriers based on poly-α-amino acids. These polyplexes should transfect target cells which are supposed to be seeded on polyimide membranes. The biodegradable polymer membrane will be implanted into the retina or used as a coating for cardiovascular prosthesis. As a cover of the implantable membranes we used polymerized methacrylamide-modified gelatin forming hydrogels and mediating a growth support for transfected cells. We focus on material bio- and immunocompatibility/immunoacceptability. The results indicated a very good bio- and immunocompatibility of the gelatin B hydrogel both in vitro and in vivo. The gelatin B hydrogel did not cause erythrocytes lysis, stimulation of proliferation (spontaneous or mitogen-induced) of mouse or human lymphoid cells, neither production of cytokines or NO in vitro. Histological examination following subcutaneous...
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Characterization of collagen from different animal tissues
Mikulíková, Zuzana ; Drábková, Michaela (referee) ; Márová, Ivana (advisor)
The aim of the proposed diploma thesis is to optimize the procedure of collagen isolation from animal tissues and methods for molecular characterization of isolates. In experimental part, isolations of collagens from animal tissues (chicken, hen, carp, and pork skin) were performed. Total protein concentration was determined by Biuret method and by TNBSA method. Both methods were used also in order to study physiological and thermal stability of the isolates under model conditions. Isolated collagens were characterized at molecular level using PAGE–SDS and microfluidic electrophoresis. Further, amino acids composition and microelement content were analyzed. Finally, the stability of isolated collagens in several types of simulated physiological and pathological conditions was tested too. During isolation relatively sufficient collagen yields were obtained (about 15 % of purified collagen per original mass of biological material). In all analyzed tissues Type I collagen was found. Thermal stability of individual samples differed according to biological source type and tissue age. Viscosimetry measurements confirmed higher stability in collagen samples of older animals. Collagenase exhibited the lowest degradation effect to bovine collagen, while selected mixed microbial hydrolases differed according to enzyme preparative type. Incubation of collagen isolates with selected human pathogens confirmed higher resistance of bovine collagen to biofilm formation when compared with the chicken one.
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Study of some modified colagen biomaterials
Zouharová, Lucie ; Drábková, Michaela (referee) ; Márová, Ivana (advisor)
The aim of the presented work is the study and biochemical characterization of some modified collagen materials (prepared on Institute of Material Science, Faculty of Chemistry, BUT), optimalization of collagen isolation from various types of animal tissues and testing of isolated collagen stability. First, isolation of collagen from five different animal tissues was performed with satisfactory yields. The concentration of total proteins was measured by Biuret and Hartree – Lowry method, the concentration of free amino groups was measured by TNBSA method. Protein analysis in colllagen preparatives was peformed by vertical electrophoresis PAGE-SDS and by microfluidic electrophoretic system Experion for comparison. Further purification and separation of collagen isolates by gel permeation chromatography was tested too. To detailed characterization thermal stability of collagen specimens was performed by high performance ultrasonic spectroscopy. Biological stability of collagen was tested in model physiological conditions.
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Rheology of collagen hydrogels and its nanocomposites
Voldánová, Michaela ; Vojtová, Lucy (referee) ; Jančář, Josef (advisor)
This bachelor thesis deals with the phenomenological description of the rheological behavior of pure collagen I and its nanocomposites with addition of hydroxyapatite in four concentrations. Measurements were performed on a rheometer in the configuration cone – plate for a range of shear rates from 0 s-1 to 100 s-1 under defined conditions. At 4 °C, the collagen in samples of a specific composition remains dissolved; collagen retains his native character and the precursors of hydrogel are in the liquid state. By heating the aqueous solution of collagen with neutral pH leeds to spontaneous crosslinking process into fibrillar structure. At 37 °C, fibrils grow into the gel structure, however, the rate of its formation is dependent on the amount of collagen fibers. The measured data are processed in the form of flow and viscosity curves, from which the rheological behavior of the sample or structural and transformational changes in response to mechanical stress and temperature changes are evaluated and compared. This knowledge can be used to manipulate with hydrogels. Generally, it can help as a basis for further development of collagen, its interaction with HAP and factors influencing their stability or effectiveness.
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Degradation of biomaterials in model physiological conditions
Mikulíková, Zuzana ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
The aim of presented work was to study degradation of selected modified protein materials and optimization of methods usable for protein concentration changes in samples that undergo proteolytic degradation. In first part overview of biomaterials used in medicine applications, biocompatibility and of collagen materials and their applications was given. In experimental part some methods for proteolysis determination were tested using standards of albumin, collagen and selected amino acids. As a part of this work proteolysis of selected modified collagen materials was observed. First, following methods for total protein analysis were tested: ninhydrin method, biuret method, Hartree-Lowry, UV-VIS spectrophotometry and TNBS method (trinitro-benzen-sulphonic acid). For collagen proteolysis determination two of these methods were optimized: biuret method (peptide group detection) and TNBS (primary amino group detection). These two methods were applied on enzyme degradation of three collagen samples: soluble collagen standard, collagen standard type I (insoluble) and modified collagen material for clinical application. In soluble and modified collagens collagenase effect exhibited decrease of peptide bounds and, simultaneously, increase of primary amino groups according to enzyme concentration and enzyme:substrate ratio. In insoluble collagen analysis was strongly influenced by structure and conformation changes of material during degradation.
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