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Rheological study of high-molecular weight hyaluronan-protonated aminoacids interactions
Zeman, Jan ; Běťák, Jiří (referee) ; Chytil, Martin (advisor)
The study deals with interactions of hyaluronic acid with protonized amino acids Lysin and 6-aminocaproic acid. To study the interactions pH-metry, conductance measurement and reometry were used. The mixtures of hyaluronan and the aminoacids of different concentrations were measured and the data were compered with data obtained from measurement of amino acid samples in pure water. Observed interactions occured in the aminoacids concentrations between 0 to 10 mmolxdm3, then the HyA carboxylic groups were fully bonded by amino acids and no more interactions were recognized.
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Preparation and application of physical hyaluronan gel
Kovářová, Lenka ; Krouská, Jitka (referee) ; Venerová, Tereza (advisor)
Bachelor's work is concerning by research in physical hyaluronan gel area. Research is focusing on its preparation, especially by interaction of hyaluronan (HyA) solution with opposite charged surfactant in physiological solution (0,15 M NaCl). In the first part of work I found out influence of molecular weight, concentration of original hyaluronan solution and the ratio of binding sites on hyaluronan chain and surfactant on amount of solids in gel, expressed in percent. Finally we can say, that this value is not influenced by molecular weight of HyA neither relation of binding sides. On the other side, concentration of original HyA solution has significant influence on amount of solids in gel. There was also researched process of gel swelling, where was set amount of water (in percent) able to take dried gel back. Analogical conclusion has been reached like amount of solids in gel. In other part were researched influence of hyaluronan molecular weight and the ratio of binding sites on hyaluronan chain and surfactant on formation of excimers and spectrum change by fluorescence spectroscopy. Pyrene, 1,3-bis(pyren-1-yl)propane (P3P) and prodan were used as fluorescence probes. Excimer emission showed at P3P, while there was no growth of intensity at 470 nm for pyrene. It was found that molecular weight does not affect the value of the ratio of excimer and monomer probe P3P, or the ratio of the first and third peaks of pyrene. The ratio of binding sites HyA and surfactant influence only relation of excimer to monomer (P3P probe), while influence to relation 1:3 hasn't been noticed for pyrene. I have compared spectrum of developed gel for prodan probe, relevant solid and swelled gel by return. It also served for drying and swelling process visualisation.
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Interaction in ionic surfactant/non-ionic surfactant/polyelectrolyte system
Pihíková, Dominika ; Sedláček, Petr (referee) ; Mravec, Filip (advisor)
The interactions in an ionic surfactant/non-ionic surfactant/polyelectrolyte system have been studied in this bachelor thesis. The value of critical micelle concentration of cationic didecyldimethylammonium chloride (DDAC) has been determined in three different mediums by fluorescence spectroscopy using Pyrene, Perylene and Nile red as probes. The CMC value of non-ionic octylphenol ethoxylate (Triton X-100) has been determined using Pyrene and Perylene as probes. The aggregation behavior of non-ionic and ionic surfactant with addition of polyelectrolyte poly(sodium4-styrensulfonate) (PSS) and native hyaluronan in aqueous solution has been investigated using Pyrene as a probe. Aggregation number in system of ionic/non-ionic surfactant has been determined by a fluorescence quenching with cetylpyridium (CPC) as a quencher and Pyrene as a fluorescence probe. Interactions in ionic surfactant/non-ionic surfactant/polyelectrolyte system were observed. This result was proved by double sigmoid Boltzman´s type curve. The addition of low molecular as well as high molecular hyaluronan had no significant effect on CMC value of the system.
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Support of physical interaction between hyaluronan and selected hydrophobic solutes
Michalicová, Petra ; Kislinger, Jiří (referee) ; Pekař, Miloslav (advisor)
The method of fluorescence spectroscopy was applied for the studying of the way of the hyaluronan-fluorescence probe system`s preparation on mutual interaction in water. Several experiments with fluorescence probes pyrene, prodan, perylene and diphenylhexatriene (DPH) had been submitted. The first part of the experiments deals with the verification of the results of T. Brown`s work and it was focused on the study of simple interaction between hyaluronan and hydrophobic compounds. In the second part of the work hyaluronan was dried at higher temperature followed by adding of the fluorescence probe. The aim of this method was the distraction of hyaluronan`s moisture packaging and the opening up the hydrophobic parts of the chain for the fluorophore. Although wide concentration ranges of fluorescence probes had been tested in the first experiments, the interactions hadn`t been observed. The similar results were obtained in the second part of the experiments.
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Viscosimetry of hyaluronan-amphiphile systems
Trojan, Martin ; Běťák, Jiří (referee) ; Chytil, Martin (advisor)
This bachelor thesis investigates the interaction between the polysaccharide sodium hyaluronate (HA) and some amphiphilic molecules. As amphiphilic molecules the aminoacids lysine and 6 – aminocaproic acids were chosen. The presence of the carboxylic group on HA and the aminogroup on the aminoacids suggests electrostatic interaction between these two compounds. This supposal offers the possibility to modificate HA and uses it as a new type of a carrier of bioactive compounds, for example medicals. The HA of two molecular weights (1.75MDa and 70kDa) were chosen for the study of the interactions with the aminoacids. Solutions of HA and stock solutions of the aminoacids were prepared for their mutual mixing in the various volume ratios. The solutions and the mixtures were measured in three types of environment: pure water, 0.15M solution of NaCl and in phosphate buffer (PBS) of pH 6. The interactions were investigated by means of reometry. Our results show, the presence of interactions between HA and the aminoacids mainly in the system consisting the 1.75 MDa HA and lysine in water. As a result of the interactions, a decrease in the viscosity of the mixtures comparing to the HA solutions was observed.
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Microviscosity probes in study of aggregation in a biopolymer-surfactant system.
Vašíčková, Kamila ; Vala, Martin (referee) ; Mravec, Filip (advisor)
The effect of cationic surfactant concentration and ionic strength on anisotropy of fluorescence of probes diphenylhexatrien and fluorescein has been investigated in the system of cationic surfactant and in the system of cationic surfactant and hyaluronan. The investigation has been done by fluorescence emission spectroscopy. Obtained anisotropy gives information about microviscosity of investigated systems. Subsequently the system of cationic surfactant and hyaluronan has been investigated by 9-(2-carboxy-2cyanovinyl)julolidine, 4-(dicyanovinyl)julolidine and 1,3-bispyrenylpropane probes. The information about the microviscosity of the system gives the integral under the emission curve of 9-(2-carboxy2-cyanovinyl)julolidine and 4-(dicyanovinyl)julolidine and the ratio between excimer and monomer of 1,3-bispyrenylpropane. It has been discovered that the ionic strength influences the anisotropy of diphenylhexatrien and fluorescein only in the fist addition of salt (concentration 0,025 mol dm-3) and that addition of hyaluronan influences the anisotropy of diphenylhexatrien and fluorescein only in samples without addition of salt. Results of measurment with 9-(2-carboxy2-cyanovinyl)julolidine and 4(dicyanovinyl)julolidine describe the formation of aggregates of catinoc surfactant with hyaluronan and characterize these aggregates from the point of microviscosity.
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Study of aggregation in a biopolymer-surfactant system at low surfactant concentration.
Stiborský, Filip ; Vojtová, Lucy (referee) ; Mravec, Filip (advisor)
In this bachelor thesis, the interaction between hyaluronate and surfactant using fluorescent spectroscopy and pyrene as fluorescent probe was studied. A cationic surfactant cetyltrimethylammonium bromide and a native hyaluronate with different molecular size was used. Before a detected critical micelle concentracion, there were no interactions observed in phosphate buffer. However, we could observe electrostatical interactions in the water systém measuring. At low concentration of surfactant (between critical aggregation concentration and critical micelle concentration), the production of gel phase appeared.
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Influence of the temperature on hydrophobic domain quality in a biopolymer-surfactant system.
Hnyluchová, Zuzana ; Kopuletá, Ema (referee) ; Mravec, Filip (advisor)
The temperature dependence on polarity has been investigated by fluorescence spectroscopy with pyrene as a probe. Pyrene was chosen thanks to its unique sensitivity to polarity of the medium. As a biopolymer was chosen 73 kDa and 1,4 MDa hyaluronic acid. Emission spectra of pyrene were measured as a function of temperature in aqous solution of CTAB in a presence and absence of sodium chloride. The results show, that the addition of specific concentration of hyaluronic acid to the sample with CTAB, mostly doesn´t have effect to change increasing/decreasing slope of polarity with the temperature.
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Influence of the preparing of a biopolymer-surfactant system on its aggregation behavior.
Pilgrová, Tereza ; Sedláček, Petr (referee) ; Pekař, Miloslav (advisor)
To study the effect of the method of preparation of biopolymer-surfactant on the aggregation properties several experiments were designed. Closer investigation was made on native hyaluronan-cetyltrimethylammonium bromide (CTAB) system. The system has been studied in the phosphate buffer in aqueous and saline solutions. The effect of the order of substances addition in the samples, the influence of different methods of preparation of certain concentrations of the solutions or the effect of dissolving powdered biopolymer and surfactant on the contrary, the resulting system were investigated. Fluorescence intensity was measured for all prepared samples and its changes were investigated. Pyrene and Nile red were used as fluorescent probes. Some samples were also measured by tensiometer. Measurement of surface tension was based on the method of divorcing the ring from the surface. It was found that the order of the mixing of solutions has a significant effect on the aggregation properties of the system and its appearance. Further effects were detected on the prepared samples by dissolving powdered biopolymer surfactants and vice versa, and environmental influences of the polarity of the system. It was found that sodium chloride abolished the effects of interactions in the system. Effect of method of preparation of certain concentration of CTAB in phosphate buffer is reflected only slightly.
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Hyaluronan for targeted drug delivery
Ureš, Tomáš ; Vávrová, Milada (referee) ; Pekař, Miloslav (advisor)
Hyaluronic acid (hyaluronan, HA) is a linear polysaccharide formed from disacharide units containing N-acetyl-D-glucosamine and glucuronic acid. HA is present in almost all biological fluids and tissues. In many cancer cells there is an upregulation of CD44, a receptor that binds HA. The receptor CD44 collocates hyaluronan in the special way. The bioconjugates built-up from the cytotoxic substances and hyaluronan are called prodrugs. The prodrugs can be used for targeted drug delivery system. Their main advantage is there is no need to medicine so high doses of pharmaceuticals and their adverse side effects are minimized. Hyaluronan can be used as well as the intra-articulation injection by osteoarthritis. HA is also used as the nutrition of joints, by treatment for diverse dermatic lesions, the repair of scars and it can be the ingredient of eye drops and nasal sprays. The cosmetic manufactures add HA into anti-wrinkle creams and anti-aging care.
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