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Modification of hyaluronan by cholic acid and the using of these derivatives for carrier applications
Kvaková, Klaudia ; Márová, Ivana (referee) ; Velebný, Vladimír (advisor)
Amphiphilic biopolymers were synthesised using esterification of hyaluronic acid (HA) and cholic acid as hydrophobic segment. First, step of synthesis involves the activation of cholic acid carboxylic moiety by reaction with benzoylchloride and triethylamine (TEA) using as solvent tetrahydrofuran (THF). The formed mixed aliphatic/aromatic anhydride (intermediate) reacted at room temperature with hyaluronic acid catalysed by 4-(dimethylamino)pyridine (DMAP) and triethylamine and using as solvent water/THF. Hydrophobized product was identified as sodium cholyl hyaluronate (HA-CA) was obtained as product of the reaction. Structure of derivative was characterised by Nuclear magnetic resonance (NMR) and Fourier Transform - Infrared Spectroscopy (FT-IR). Size exclusion chromatography (SEC-MALLS) was used to determine molecular weight of derivative to evaluate any possible degradation of hyaluronan during modification. Rheological properties of these substances were also examined and confirmed non-degradation. The hydrophobized hyaluronic acid properties were evaluated for application as drug delivery system. Therefore, two non-polar compounds were encapsulated (coenzyme Q10 and curcumin). The size of formed polymeric micelles was characterised by dynamic light scattering (DLS).
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Interaction between amphiphilic fluorescent probes and hyaluronan
Střondalová, Hana ; Vala, Martin (referee) ; Mravec, Filip (advisor)
This bachelor thesis dealt with studying the interaction of amphiphilic fluorescent probes with hyaluronan because these probes could significantly help in clarifying the links between hyaluronan and surfactants. This complex could be a great benefit in targeting drug distribution. This thesis was focused on the interaction between hyaluronan and amphiphilic fluorescent probes – specifically with dodecylacridine orange. First explored was the interaction with hyaluronan, and then with the hyaluronan – surfactant system. Cetyltrimethylamonium bromide was selected as surfactant. Samples were examined using fluorescence spectroscopy. Emission and absorption spectrum of dodecyl acridine orange was measured. This experiment was based on the hypothesis that dodecylacridine orange forms dimers as acridine orange and nonylacridine orange. It was found that in a system of hyaluronan-probe, dodecyl acridine orange was pushed out of the complex by cetyltrimethylamonium bromide, which was bounded instead. Surfactant interacts with hyaluronan binding positions - with carboxyl groups.
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Native hyaluronan as a delivery system for hydrophobic drugs
Černá, Eva ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
The aim of this paper is to discover whether it is possible to use the native form of hyaluronic acid as a hydrophobic drug carrier for a targeted distribution in the body. In its structure, hyaluronic acid is a linear high molecular weight biopolysaccharide which is found in most living organisms. Hyaluronan is involved in many physiological processes and therefore is essential for the functionality of the human body. It is in most tissues of the human body, high concentration is in the skin, the vitreous body and is also observed in cancer cells that contain several receptors for hyaluronan. These receptors include CD44 and RHAMM. The interaction of the hyaluronic acid delivery system and the hydrophobic medicinal with these receptors could ensure a free passage for drugs to the affected tissue, where the release of the drug would destroy the affected cells. The drug would directly target the damaged tissue and did not burden the rest of the body like the cytotoxic agents do. In this paper the native form of hyaluronic acid, which we normally find in the human organism, was chosen as the carrier. Its properties do not stand above other carrier systems, but its biocompatibility and biodegradability in the body greatly exceed them. High molecular weight hyaluronic acid was used as a carrier and the hydrophobic dye sudan red G, a substance of similar properties, was used instead of a hydrophobic drug.
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Crosslinking of polysaccharide microfibers
Svidroňová, Barbora ; Abdellatif, Abdelmohsan (referee) ; Vojtová, Lucy (advisor)
Všeobecne, cieľom tejto diplomovej práce bola príprava a charakterizácia sieťovaných hyaluronových mikrovláken, ktoré by boli stabilné vo vodnom prostredí s vhodnými mechanickými vlastnosťami. Vlákna pripravené technikou zvlákňovania z roztoku boli sieťované pomocou roztoku so sieťovacím činidlom 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimidom alebo roztoku s dvoma sieťovacími činidlami 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimidom a N-hydroxysuccinimidom, vedúcim k amidácii a tvorbe esterových väzieb. Charakterizácia pripravených vzoriek je hlavným cieľom experimentálnej časti práce. Charakteristiky botnání boli vykonané na určenie stability vláken v troch rôznych roztokoch (s pH 7.4, 3 a 11). Na určenie termickej stability bola využitá termogravimetrická analýza a na stanovenie esterifikácie a amidácie bola použitá infračervená spektroskopia s Fourierovou transformáciou. Mechanické vlastnosti vláken boli študované pomocou testovania závislosti stress-strain. Ďalej boli testované reologické vlastnosti ako aj mikroštruktúra a povrch vláken pomocou skenovacieho elektrónového mikroskopu. Vlákna pred chemickým sieťovaním vykazovali nižšiu stabilitu vo všetkých troch roztokoch, termálna stabilita bola taktiež nižšia ako stabilita zosieťovaných vláken. Pre vlákna chemicky nemodifikované so sieťujúcim činidlom, sa objavil iba jeden typ píku pre esterifikáciu. Infračervené spektrum chemicky zosieťovaných vláken ukázalo prítomnosť dvoch píkov pre esterifikáciu, čo je prejavom efektivity sieťovacieho činidla. Amidácia bola tiež výraznejšia pri zosieťovaných vláknach, špeciálne pre vlákna sieťované dlhú dobu a v roztoku s vyššou koncentráciou sieťujúceho činidla. Kvôli nerovnomerným vláknam, mechanické vlastnosti nevykazovali žiadnu závislosť na sieťovaní. Štúdium reológie ukázalo, že viskozita vlákna rozpusteného vo vode je menej závislá na šmykovej rýchlosti ako prášok hyaluronanu sodného rozpusteného vo vode. Napriek mnohým rôznym metódam charakterizácie vláken, ktoré boli použité v tejto práci, je stále veľa možností pre lepšiu charakterizáciu a bližšie pochopenie tohto biopolymérneho materiálu.
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Influencing of caffein absorption from cola-type beverages
Osecká, Karolína ; Márová, Ivana (referee) ; Pekař, Miloslav (advisor)
This diploma thesis was focused on basic physicochemical properties of caffeine and investigation of the interaction between the polysaccharide sodium hyaluronan (HA), pectin (PEC) or lignohumate (HUM) and the alkaloid caffeine (CAF). The reason why this thesis was focused on study of aqueous solutions of hyaluronan or pectin with caffeine is that the presence of polysaccharide- caffeine complex could be beneficial for slowing the absorption of caffeine. In the theoretical part of the diploma thesis there is described a group of alkaloids, which caffeine belongs to and also polysaccharides hyaluronic acid and pectin. The most attention has been paid to caffeine, its properties and effects on the human organism. This diploma thesis also deals with non-alcoholic beverages with caffeine, 4-methylimidazole, and phosphoric acid. The last chapter of the theoretical part is dedicated to fluorescence spectroscopy. In the experimental part of this work I deal with the basic properties of caffeine and interaction between the caffeine and selected polysaccharides or lignohumate. At first, the chemical and physical properties of caffeine were determined. Based on these results the interaction of caffeine and hyaluronan or pectin was studied by using the fluorescence and absorbance. The HA of molecular weight of 1,7 MDa and pectin from citrus fruits were chosen for the study of the interaction with the caffeine. These two substances were mixed with the caffeine of concentration contained in Coca-Cola. The results of interaction that would lead to the influence of the emission or absorption properties of caffeine, were not proved. As a part of the work there was determined how pectin behaves in strongly acidic solution and then there was monitored the pH, conductivity and solubility of caffeine in water by using thermogravimetry and visual experiments. The obtained results of the interaction of hyaluronan-caffeine, pectin caffeine or caffeine-lignohumate can be used for description of the behavior of caffeine in the presence of selected polysaccharides and natural organic substance.
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The characterisation of surfactant CAE
Obršlíková, Monika ; Pekař, Miloslav (referee) ; Hurčíková, Andrea (advisor)
CAE is a cationic surfactant derived from DL-Pyrrolidone Carboxylate, L-Arginine and a fatty acid. This surfactant is mainly used in the cosmetic industry. The exact value of critical micellar concentration of CAE is not known yet. In this research there were examined ultrasonic velocity, density, surface tension and scattered light intensity of CAE solutions in ultra-pure deionized water, in 10mM NaCl, 100mM NaCl and 150mM NaCl.
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Determination of hyaluronan by electromigration methods
Bártová, Adéla ; Mravcová, Ludmila (referee) ; Řezáčová, Veronika (advisor)
This thesis is focused on description hyaluronic acid, characterization of its behaviour in water solutions, its chemical-physical properties and its using in different industrial sectors. The next part deals with possibilities of its analysis. The following section of the thesis is focused on electromigration techniques with special attention dedicated to capillary electrophoretic methods, especially capillary zone electrophoresis. The aim of this thesis is optimization of the method of determination of hyaluronic acid in water solutions by capillary zone electrophoresis.
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The hydration of hyaluronic acid
Průšová, Alena ; Šimon, Peter (referee) ; Kučerík, Jiří (advisor)
Hydratace patří mezi nejdůležitější faktory ovlivňující sekundární strukturu a tím i funkci molekul v živých systémech. Díky vysoké afinitě tvoří molekuly vody specifické struktury jejichž složení a fyzikální vlastnosti jsou ovlivněny přítomností studované látky. Hyaluronan patří mezi biomolekuly s obrovskou schopností vázat a zadržovat vodu. Cílem této práce bylo prozkoumat hydratační vlastnosti hyaluronanu o různé molekulové hmotnosti a vyčíslit množství molekul vody v jednotlivých hydratačních vrstvách. V první části práce byla využita metoda diferenční kompenzační kalorimetrie. V druhé části diplomové práce, na základě rozdílné kompresibility, byla vázaná voda studována metodou vysoko rozlišovací ultrazvukové spektroskopie.
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Phase separation in the system of aminoclay-biopolymer
Plotěná, Michaela ; Pekař, Miloslav (referee) ; Mravec, Filip (advisor)
The aim of this diploma thesis was to study the structure and to evaluate the properties of the hydrogel prepared by the interaction of the aminolclay with the biopolymer. Representatives of the biopolymers were selected from low to medium molecular weight sodium hyaluronate and sodium polystyrenesulfonate. On the basis of the experiments carried out, it was found that phase separation takes place only when the aminolclay interacts with medium molecular weight hyaluronan (MMW). In the experimental part, analyzes of this sample were carried out in order to determine the formation of phase-separated hydrogel by influencing the solution by ionic strength, investigation of hydrogel extinction in various organic solvents, stability of hydrogel under extreme temperature conditions, the effect of storage on its degradation, etc. Viscoelastic properties were experimentally proven by rheology and thermal analysis detected binding water. Inhibition of microorganisms was confirmed by antibacterial diffusion assays. All experiments were carried out for the use of the Aj-HyA hydrogel (MMW) in the field of medical applications, specifically for the modern method of wet wound healing of the skin.
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