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Influence of concentration of surfactant component and temperature on interactions between hyaluronan and katanionic vesicular systems
Janáková, Kristýna ; Jugl, Adam (referee) ; Krouská, Jitka (advisor)
The influence of various concentrations of surfactant component and various temperatures on interactions of hyaluronan with catanionic vesicular systems were examined using isothermal titration calorimetry. The measurements were performed at two different concentrations of surfactant component and three temperature values. The reason for studying the interactions was to explore the possibility of these systems serving as carriers of drugs in the future. Catanionic vesicular systems consisted of a cationic surfactant CTAB, an anionic surfactant SDS and of a positively charged two-chain surfactant DODAC. The solution of negatively charged hyaluronan with concentration of 0,5 mM was used for all measurements.
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Characterization of medical biopolymers by ultrasound spectroscopy
Jugl, Adam ; Krouská, Jitka (referee) ; Hurčíková, Andrea (advisor)
Using high resolution ultrasonic spectroscopy has been investigated hyaluron solutions of various molecules weights depending on their concentration and solution temperature. Furhermore, the influence of ionic strenght on the properties of solutions by dissolving hyaluronan in 0.15 M aqueous solution of sodium chloride. For comparison the properties of the hyaluronan solutions were compared with aqueous solutions of carrageenan. It was found that hyaluronan in solution behaves the same, regardless of the weight, temperature and concentration.
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Study of interactions of hyaluronan-amino acids
Jugl, Adam ; Smilek, Jiří (referee) ; Hurčíková, Andrea (advisor)
The master´s thesis deals with the study of the interaction between the polysaccharide hyaluronan of diffrerent molecular weights with the amino acids arginine, lysine, arginine hydrochloride and 6-aminocaproic acid. They are expected interaction between carboxyl groups of hyaluronan and amino groups of amino acids. These interactions were investigated by using ultrasonic spectroscopy, DLS, measuring pH and conductivity. Obtained results were compared with sodium polystyrene sulfonate. With ultrasonic spectroscopy was observed a change of concentration inkrement for titration of amino acid to water or polymers solutions especially for high molecular weight hyaluronan and for NaPSS in combination with 6AKK in concentration range of added amino acid 0–30 mM. The size of this change could mean a degree of interaction between polymers and amino acids. This theory has not been confirmed by other methods. By pH and conductivity measurements interations between arginine and low molecular weight hyaluronan and NaPSS were only confirmed. There was no possibility to make unequivocal conclusions from determination of particle size and zeta potential by DLS. Overall, the issue of the interaction of amino acids with polyanions was proved above expectations complex and will be appropriate to further expand the observations made in this thesis.
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Sun protection factors determination for cosmetic emulsions
Slechanová, Veronika ; Jugl, Adam (referee) ; Smilek, Jiří (advisor)
The bachelor thesis deals with the anatomy and physiology of the skin, ultraviolet rays, sunscreens and current methods used to measure the value of sun protection factor. One of the goals of the thesis is to get the overview of the UV filters currently widely used in cosmetic products and giving them the required protection against the sun. The obtained knowledge was subsequently used for the determination of the sun protection factors in selected sunscreens by in vitro methods. The measurement provided satisfying results comparable with the values given on the label of the tested products. However, it is still necessary to optimize the methodology even more in order to obtain data with lower deviations and especially with much higher reproducibility.
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Elastin hydrogels
Burianová, Veronika ; Trudičová, Monika (referee) ; Jugl, Adam (advisor)
This bachelor thesis is focused on elastin hydrogels for medical application. The aim of the experimental part was using elastin as an additional substance in polysaccharide gel matrices. The most available elastin material was elastin from bovine neck ligament. Because of the insolubility of elastin, it needed to be hydrolysed. Elastin was hydrolysed using potassium hydroxide. The hydrolysis product was soluble and thermal stable elastin peptides, called elastin. Prepared -elastin was incorporated in agarose gel matrices to produce semi-IPN hydrogels based on elastin and agarose. These hydrogels were characterized by rheologicalamplitude and frequency sweeps. The results of measuring clearly proved that -elastin addition caused increased hydrogel stiffness, but other changes were not observed.
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Analysis and optimization of the dyeing process of surgical instruments
Roušarová, Kateřina ; Jugl, Adam (referee) ; Krouská, Jitka (advisor)
This bachelor thesis deals with the issue of staining of disposable surgical instruments in the corporate facility of the industrial partner with whom the cooperation took place. Within the framework of this bachelor thesis an analysis of the input organic raw materials, which are an essential part of the manufactured dye for instrument staining, was carried out. The basic characterization of the raw materials was carried out by available methods at the Faculty of Chemistry, such as density measurement with a hydrometer, viscosity measurement with an automatic viscometer and viscosity versus shear rate with a rheometer. Subsequently, a visual assessment of the behaviour of the individual liquid feedstocks in water was performed. The tabulated values of the raw materials from the safety data sheets were verified by these methods. It was found that the starting ingredients are insoluble in water, in which they precipitate and thus significantly affect the viscosity of the resulting suspension. The actual laboratory preparation of the paint samples was carried out, where 7 samples were mixed, varying in the volumes of the input liquid organic components. These samples were subjected to rheological measurements, which resulted in the dependence of viscosity on shear rate. A range of 0,4–0,8 Pas at a shear rate of 10 s-1 was specified by the industrial partner for the resulting viscosity of the mixed suspension, within which 4 samples fell. The result of the spout test performed using a Ford spout cup determined the time of suspension discharge from the cup, which can be used to verify the quality and correct consistency of the paint mixed in company operation. All samples were stained with surgical instruments and the quality of staining was evaluated after firing. Based on the requirements of the industrial partner, 4 samples were designed falling within the required viscosity range and suitable for staining surgical instruments. The results have been passed on to the industrial partner, who has the discretion to implement new dye preparation procedures in their operation.
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Hydrogel fantoms in sono diagnostic
Koňaříková, Anna ; Jugl, Adam (referee) ; Hurčíková, Andrea (advisor)
As part of the practical part of this diploma thesis, an internship took place in the Danish company Dansk Phantom Service, which is engaged in the production of ultrasound phantoms. The purpose was to better understand the ultrasound devices used to characterize these phantoms. Part of the phantom material was provided for measurements on ultrasound devices occuring at the faculty of chemistry of BUT to compare results provided by these devices. The follow-up task was to put into operation a digital oscilloscope, which is used to characterize phantoms, and to create a standart operating procedure. Furthermore, the material of the american company Humimic Medical was characterized and the possibilities of its use for the requirements of the Phillips company were assessed, with the subsequent addition of carbon fibers to the material for the modification of phantom properties. The possibility of preparing a viscous phantom from a mixture of agar, glycerol and water with subsequent charakterization of experimental samples was also investigated. It was found that the values from different ultrasound devices are comparable, differing only in small deviations. Humimic’s Medical material has potencial for specific applications, as does carbon fiber for property modification. A basic mixture of viscous phantom was created that would potentially meet the requirements. However, this basic mixture need to be further modified.
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Influence of concentration of surfactant component and temperature on interactions between hyaluronan and katanionic vesicular systems
Janáková, Kristýna ; Jugl, Adam (referee) ; Krouská, Jitka (advisor)
The influence of various concentrations of surfactant component and various temperatures on interactions of hyaluronan with catanionic vesicular systems were examined using isothermal titration calorimetry. The measurements were performed at two different concentrations of surfactant component and three temperature values. The reason for studying the interactions was to explore the possibility of these systems serving as carriers of drugs in the future. Catanionic vesicular systems consisted of a cationic surfactant CTAB, an anionic surfactant SDS and of a positively charged two-chain surfactant DODAC. The solution of negatively charged hyaluronan with concentration of 0,5 mM was used for all measurements.
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Hyaluronan-amino acids interactions
Jugl, Adam ; Maršálek, Roman (referee) ; Mráček, Aleš (referee) ; Pekař, Miloslav (advisor)
The presented dissertation focuses on non-covalent interactions of hyaluronan of different molecular weights (9–1540 kDa) with basic (oligo)-amino acids (especially arginine) and the antimicrobial peptide cecropin B. High-resolution ultrasonic spectroscopy (HR-US), isothermal titration calorimetry (ITC) and potentiometric titration techniques were chosen to investigate the interactions. The thesis focuses on the characterization of interactions, especially with respect to the used molecular weight of interacting polymers and the ionic strength of the environment. Whether interactions occur or not was determined primarily by the length of the arginine oligomer chain. For monomeric amino acids, the interactions were investigated mainly by potentiometric titrations. Interactions were observable from arginine oligomers with eight monomer units. The molecular weight of hyaluronan mainly affected the intensity of the interactions. The transition between the individual conformations of hyaluronan (rod and random coil) was especially significant. Investigation of interactions was performed in water, in solutions with different concentrations of sodium chloride and in PBS. The sufficiently high ionic strength of the solution was able to suppress the interactions in water between the oligomers of arginine and hyaluronan. The basic antimicrobial peptide cecropin B has been shown to interact with hyaluronan in water but not in PBS. Based on these results, it was possible to conclude that the hyaluronan-cecropin B system would be particularly suitable for topical applications.
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Sun protection factors determination for cosmetic emulsions
Slechanová, Veronika ; Jugl, Adam (referee) ; Smilek, Jiří (advisor)
The bachelor thesis deals with the anatomy and physiology of the skin, ultraviolet rays, sunscreens and current methods used to measure the value of sun protection factor. One of the goals of the thesis is to get the overview of the UV filters currently widely used in cosmetic products and giving them the required protection against the sun. The obtained knowledge was subsequently used for the determination of the sun protection factors in selected sunscreens by in vitro methods. The measurement provided satisfying results comparable with the values given on the label of the tested products. However, it is still necessary to optimize the methodology even more in order to obtain data with lower deviations and especially with much higher reproducibility.
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