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The Effect of Synovial Fluid Constituents on Lubrication of Hip Joint Replacements
Nečas, David ; Daniel,, Matej (referee) ; Sawae, Yoshinori (referee) ; Hartl, Martin (advisor)
Dizertační práce se zabývá mechanismy mazání v náhradách kyčelního kloubu. Byla provedena systematická studie formování proteinového filmu při zahrnutí různých materiálů a provozních podmínek. Hlavní pozornost je přitom věnována roli jednotlivých proteinů obsažených v synoviální kapalině při současné přítomnosti dalších proteinů. Jelikož metody aplikované v předchozích studiích neumožňovaly separovat jednotlivé složky maziva, byla vyvinuta optická měřící metoda na principu fluorescenční mikroskopie. Z důvodu verifikace metody byly provedeny dvě nezávislé studie zaměřené na měření tloušťky mazacího filmu a dělení maziva na výstupu mazaného kontaktu. Z důvodu určitých limitací fluorescenční mikroskopie byla dále využita i metoda optické interferometrie, jejíž využití je ilustrováno ve studii zabývající se formováním mazacího filmu v náhradách kyčelního klubu při uvažování reálné konformity třecích povrchů. Závěrečná část práce představuje nový metodologický přístup založený na in situ pozorování kontaktní oblasti umožňující popsat roli jednotlivých proteinů ve vztahu k vývoji tloušťky mazacího filmu. Práce obsahuje originální výsledky, které přináší nové poznání v oblasti biotribologie náhrad kyčelního kloubu vedoucí k dalšímu vývoji implantátů při snaze zabránit jejich selhání v důsledku omezené životnosti.
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The Effect of Synovial Fluid Constituents on Lubrication of Hip Joint Replacements
Nečas, David ; Hartl, Martin (advisor)
Dizertační práce se zabývá mechanismy mazání v náhradách kyčelního kloubu. Byla provedena systematická studie formování proteinového filmu při zahrnutí různých materiálů a provozních podmínek. Hlavní pozornost je přitom věnována roli jednotlivých proteinů obsažených v synoviální kapalině při současné přítomnosti dalších proteinů. Jelikož metody aplikované v předchozích studiích neumožňovaly separovat jednotlivé složky maziva, byla vyvinuta optická měřící metoda na principu fluorescenční mikroskopie. Z důvodu verifikace metody byly provedeny dvě nezávislé studie zaměřené na měření tloušťky mazacího filmu a dělení maziva na výstupu mazaného kontaktu. Z důvodu určitých limitací fluorescenční mikroskopie byla dále využita i metoda optické interferometrie, jejíž využití je ilustrováno ve studii zabývající se formováním mazacího filmu v náhradách kyčelního klubu při uvažování reálné konformity třecích povrchů. Závěrečná část práce představuje nový metodologický přístup založený na in situ pozorování kontaktní oblasti umožňující popsat roli jednotlivých proteinů ve vztahu k vývoji tloušťky mazacího filmu. Práce obsahuje originální výsledky, které přináší nové poznání v oblasti biotribologie náhrad kyčelního kloubu vedoucí k dalšímu vývoji implantátů při snaze zabránit jejich selhání v důsledku omezené životnosti.
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Bílkoviny krevní plazmy ovcí
DŘÍZHALOVÁ, Blanka
Plasma protein shave many important functions in the organism. Gamma globulins are carriers of immunoglobulins which play animportant role in the immune response. Their contentis primarily given by the health burden of the organism. The aimofthe study was to determine the individual protein fractions in the blood plasma of ewes and lambs, comparemutual relations between total plasma proteins and thein variol factions and assess the concentrations of individual plasma proteins, mainly globulin, in connection with the aktivity of the thyroidgland, physiological state, and increments. The sampling was carried out in the spring (25.3.) and the autumn (14.10) 2013. The individual protein fractions were determined from the serum by the means of electrophoresis. The results show that the concentration of proteins in the blood plasma of bothewes and ewe lambs and ram lambs was high due to haemoconcentration, heat stress during sampling, grazing young green forage, comprising a large number of protein aceous substances, and increasing demands on energy for milk production, especially in the early stagesoflactation. Theconcentrationofproteins in theblood plasma oflambspertains to thegrowthproduction. It establishes a correlation between the concentration of plasma proteins and the aktivity of the thyroidgland. It also confirmes higher concentrations of plasma proteins of lambs correlating to thein higher daily gain. Due to the high concentration of total protein in the plasma, the level of its fractions was high as well. After the conversion to a percentage, the level of - globulins in blood plasma in all categories was within normal limits in the range of 14-27%. The concentration of - globulins in blood plasma increased in relation to the parasitological findings coccidia of the genus Eimeria and gastrointestinal nematodes. Relations between the kontent of plasma proteins in the blood of the lambs and ewe sobserved were in most casespositive. There was a strong dependence between the total protein and globulins. Even among other fractions of plasma proteins and globulins correlation coefficient was almou always positive.
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Experimental analysis of lubricant film formation in hip joint replacements
Švachová, Michaela ; Dzimko, Marián (referee) ; Nečas, David (advisor)
This diploma thesis deals with an experimental analysis of lubricant film formation in hip joint replacements. The main objective is to clarify the effect of mean speed, slide-to-roll ratio, and material of femoral head on the development of film thickness, focusing on the role of particular constituents contained in model synovial fluid, such as albumin and -globulin. For this purpose, a model ball-on-disc configuration was applied, while the development of lubricant film was evaluated using the combination of fluorescent microscopy and optical interferometry. To better understand the process, coefficient of friction between implant surfaces was later investigated as well. The effect of material, slide-to-roll ratio, mean speed and model fluid composition was analysed. Results indicate that the main parameter, influencing the character of film formation, is slide-to-roll ratio. Under most conditions, the dominant constituent responsible for the film thickness development was albumin. Coefficient of friction is affected mainly by the material of implant. The thesis contains original scientific results extending the knowledge in the area of hip joint biotribology.
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Hyaluronan-albumin complexes behavior at physiological conditions.
Šuleková, Nikola ; Kratochvílová, Romana (referee) ; Chytil, Martin (advisor)
This thesis discusses the interactions of low molecular weight and high molecular weight hyaluronic acid (HA) with bovine serum albumin (BSA) in physiological environment. It is based on previous work dealing with HA and amphiphilic substances which are currently widely studied for its potential applications in medicine. Solutions of HA with fixed concentration and albumin of concentration in the range of 0,25 – 20 g/l were prepared at room temperature and at 37°C and examined by rheometry and turbidimetry. It was observed that the maximum absorbance increases with increasing concentration of BSA and does not show variations depending on the temperature of preparation. On the other hand, the turbidity occurs in significant differences between the samples prepared at ambient temperature and at 37°C. Overall, the turbidity increases with the concentration of BSA. Rasing the temperature caused the increase in viscosity of the samples, which was further varied with the concentration of BSA. Mixed solutions of high molecular weight HA and BSA showed the highest turbidity, maximum absorbance and viscosity, while the solutions of BSA showed the lowest values. The results indicate formation of complexes, of which properties are dependent on BSA concentration, the molecular weight of HA, and the temperature of preparation.
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Study of hyaluronan-albumin systems using light scattering methods and calorimetry
Sereda, Alena ; Hermannová, Martina (referee) ; Chytil, Martin (advisor)
This thesis, which is a continuation of the previous Bachelor thesis, is dedicated to the study of polyelectrolyte complexes between hyaluronan (HA) and bovine serum albumin (BSA). Interactions between HA and BSA and a formation of complexes were studied by SEC-MALLS method, where a molar mass, a root mean square (rms) radius, a hydronamic radius and an intrinsic viscosity of particles of the system were defined. Furthermore the interactions were studied by calorimetric measurement ITC, where thermodynamic character of complex formation was determined. Additionally, dynamic and electrophoretic light scattering methods (DLS and ELS) were applied, where hydrodynamic radius and a value of the zeta potential were defined. Also the effect of higher temperature on the character and complex formation was examined by SEC-MALLS and ITC measurements. The interactions were confirmed at any of the used media, but with different efficiency. It was also proved that complexes become smaller in their radii and viscosity with growing BSA concentration. Furthermore it was proved, that the high ionic strength hinders surface charges of HA and BSA molecules and minimizes their mutual interactions. At the higher ionic strength the radii of the complexes, their intrinsic viscosity and zeta potential are increased. The higher temperature has only minimal effect on the formation of the complexes.
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Investigation of Polyelectrolytes Interactions with Cationic Aminogroups-containing Amphiphiles
Zeman, Jan ; Běťák, Jiří (referee) ; Chytil, Martin (advisor)
The study deals with interactions of polyelectrolytes polystyrene sulfonate and hyaluronic acid with nitrogenic amphiphilic substances, represented by lysine and albumine. To study the interactions pH-metry, conductance, viscositic and turbidity measurement, DLS and reometry were used. All mixtures of different concentrations were measured and the data were compered with data obtained from measurement of samples with amphiphilic sumstances without polyelectrolytes. Observed interactions occured in the aminoacid concentrations between 0 to 20 mmoldm-3, then the PSS interaction groups were fully bonded by lysine and no more interactions were recognized. The same behaviour were observed in albumine solutions with concentration under 2 gdm-3.
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SEC-MALLS study on hyaluronan-albumin interactions
Sereda, Alena ; Kalina, Michal (referee) ; Chytil, Martin (advisor)
This work is focused on interactions of hyaluronan (HA) and bovine serum albumin (BSA). These interactions were studied by SEC-MALLS method, where molar mass, root mean square (rms) radii, hydronamic radius and intrinsic viscosity of particles of the system were defined. Additionally, interactions were examined by measurement of DLS and zeta potential, where hydrodynamic radius and a value of the zeta potential were defined. The interactions were confirmed at any of the used media, but with different efficiency. Furthermore it was found out, that the high ionic strength minimizes the range of the interactions, magnifies the radii of the complexes, their intrinsic viscosity and zeta potential. It was proved that complexes become smaller in their radii and viscosity with growing BSA concentraton.
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Polysaccharide-protein gels
Hájovská, Pavla ; Smilek, Jiří (referee) ; Chytil, Martin (advisor)
This bachelor thesis deals with gelation of albumin solutions and mixed solutions of albumin and the high molecular weight hyaluronic acid due to heating. Study was carried out by measuring rheological properties of the solutions, formed gels and gelation process. For the protein samples in water, the effect of concentration, ionic strength and pH were tested. For mixed solutions, the effect of concentration and a composition of the polymeric component were tested. With increasing concentration of the polymeric component, the gel point is shifted towards lower temperature values, with the concentration difference of 2 % (w/v) up to 5°C. The resulting gels exhibit higher values of loss and storage moduli. Similar behavior was observed also in the samples influenced by the ionic strength as, a result of alternation of the electrostatic interactions between the charged groups of the polymer chains and as a result of change of this charge due to the pH reduced below the pI value of the protein.
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