|
|
The Role of Spinneret Glands and Specific Features of Silk Production in Tarantulas (Araneae: Mygalomorphae)
Sýkorová, Barbora ; Říhová, Dagmar (advisor) ; Dolejš, Petr (referee)
This bachelor thesis is a review of scientific papers, monographs and internet sources, which focus mainly on the spinning apparatus and silk production in Mygalomorphae. The thesis is enriched with pictures that could help the reader to better navigate the topic. Spiders belong to arthropods. They are divided into the infraorders Araneomorphae, Mesothelae and Mygalomorphae. Spiders have a body divided into a cephalothorax and an opisthosoma, connected by a pedicel. The digestive system of spiders is specific in that it only allows them to take in liquid food. Almost all spiders have developed venom glands. Spinning activity is a very important feature of spiders. An important part of the spinning apparatus in the spinning nipples varies from family to family, but usually there is a reduction in their number. The basic functional and structural units of the spinning apparatus are the spinning glands, which transform on the surface of the spinning nipples into spigots, through which the silk is expelled to the surface. The silk is used by spiders to form snare or to form protective egg cases- cocoons. In the Czech Republic we can see three species of the family Atypidae (genus Atypus): Atypus affinis, Atypus piceus and Atypus muralis. KEYWORDS Spiders, silk glands, spigot, spidroin, family Atypidae,...
|
|
|
Polymer-based therapeutics for immunooncotherapy
Kashmel, Pavel ; Etrych, Tomáš (advisor) ; Bárta, František (referee)
This master thesis describes the synthesis, physico-chemical characterization and preliminary biological testing of water-soluble polymer conjugates of the model drug ZM241385. This drug was first derivatized and then connected to a polymer carrier in order to prepare a system suitable for targeted drug transport to tumor tissues. Improved pharmacokinetic parameters of the prepared polymeric systems carrying ZM241385 should be the basis for increased therapeutic activity of the polymeric nanosystem in tumor immunotherapy. Polymeric precursors were synthesized by controlled RAFT polymerization in order to prepare highly defined carrier systems. In the framework of this master thesis, two derivatives of the selected drug were prepared, differing in the carboxylic acid used and the mode of their binding to the polymeric carrier. For derivatization, 4-(2-oxopropyl)benzoic acid was used, in which case the prepared derivative was bound to the carrier via a hydrazone bond. This bond is pH sensitive and shows high stability at pH 7.4 (corresponds to the pH of the blood stream), and at a slightly acidic pH 5.5 (corresponds to the microenvironment of the tumor, or endosomes of tumor cells), its rapid hydrolysis occurs. For the second derivative, 5-azidopentanoic acid was used. An uncatalysed click reaction...
|
|
|
Preclinical use and critical evaluation of micro-CT from the perspective of oral and maxillofacial surgery.
Bartoš, Martin ; Foltán, René (advisor) ; Naňka, Ondřej (referee) ; Bulik, Oliver (referee)
The preclinical imaging method micro-CT (microtomography) allows the visualization and quantification of the structure of samples at a resolution of micrometers. Its' importance is increasing globally. In addition to several advantages (non-destructive, the possibility of direct 3D analysis, time efficiency, etc.), micro-CT also has some significant limitations (problematic validation of results, image artifacts, significant influence of image modifications, etc.). This thesis focuses on the application of micro-CT in the field of research and development of metallic and non-metallic materials promoting bone healing with their possible clinical applications. The first part addresses the limitations of micro-CT through several studies. A comparison of pore sizes in biomaterials utilizing scanning electron microscopy (SEM) and micro-CT was performed, and the complications of pore size evaluation were presented. SEM image analysis leads to significantly higher values than micro-CT (approximately three times), which allows for comparison of the studies using only one of these methods. Validation of micro-CT 3D analysis results based on calibration phantoms with complex structure, to date, is not possible. We therefore developed software generating phantom datasets of 3D objects with well-defined...
|
|
|
Fabrication of dental glass-ceramics
Hasalíková, Tereza ; Dlabajová, Lucie (referee) ; Bartoníčková, Eva (advisor)
This bachelor´s thesis deals with the study of glass-ceramic materials and their use in dentistry. Nowadays, studies are placed on health harmless of the material, the biological ability to adapt to the host tissue, mechanical properties, affordability, easy and fast production, aesthetics and quick recovery of the patient. The theoretical part of the work deals with various materials from various input materials used for dental substitutes. Special attention is paid to glass-ceramic and ceramic biomaterials, their preparation, heat treatment and health testing. The experimental part deals with the preparation of powder materials by the sol-gel method. Of the larger number of samples, those were selected for gelation and showed good XRD and heat microscopy results. The selected samples were subsequently subjected to heat treatment to form a glass ceramic material. The products were characterized by XRD phase composition in terms of phase temperature behavior by TG-DTA analysis, heat microscopy and SEM morphology analysis of prepared particle.
|
|
|
The influence of simulated body fluids on the apatite production
Horváthová, Lenka ; Beranová, Denisa (referee) ; Bartoníčková, Eva (advisor)
This bachelor thesis deals with the interaction of various simulated body fluids with ceramic biomaterials. It includes fluid preparation, sample preparation and subsequent analysis of their interaction. Individual samples of biomaterials were exposed to a simulated body fluid for a certain amount of time. After this time, a change in the calcium and phosphorus content of the solutions was determined. At the same time, an electron microscope analysis of sample surface was performed where the dependence of calcium and phosphorus changes was demonstrated. Electron microscopy analysis revealed the formation of new phases on the surface of the studied materials.
|
|
|
Cell-biomaterial interactions in hard and soft tissue engineering
Zárubová, Jana ; Bačáková, Lucie (advisor) ; Mikšík, Ivan (referee) ; Slepička, Petr (referee)
Tissue engineering is an interdisciplinary field which aims to create substitutes of damaged tissues by combining cells with biomaterials. Cells are extremely sensitive to their microenvironment and so the cell response to biomaterials can be regulated by different extrinsic stimuli and alterations of biomaterial properties. Successful implant integration into the tissue can therefore be promoted by appropriate surface roughness, chemical composition, adhesion ligand density, as well as the availability of growth factors. This thesis mainly focuses on the development of orthopedic replacements and the improvement of the currently used blood vessel prostheses. Through the study of cell-biomaterial interactions, it was demonstrated that superimposed topography with features ranging from the nano to micro scale promotes cell spreading, proliferation, and the metabolic activity of osteoblast-like cells. Moreover, when comparing the chemical composition of biomaterials for orthopedic implants, higher osteoblast densities were observed on composites with 5-15 vol. % of calcium phosphate nanoparticles, while concentrations of 25 vol. % did not support cell proliferation. Cell viability, however, was not affected. In vivo, a more intensive formation of new bone tissue, was found on samples containing...
|
|
|
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
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
guest ::
