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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Oral lichen planus – etiopathogenesis and management

Siponen, M. (Maria) 18 January 2017 (has links)
Abstract Oral lichen planus (OLP) is a chronic immune-mediated mucosal disease with unknown etiology. According to the current view, the pathogenesis of OLP involves activation of T-cell mediated immunity against the epithelial keratinocytes. A proportion of OLP patients are affected by painful symptoms, and the risk of oral cancer is increased in OLP. There is no curative treatment for OLP. Topical corticosteroids are used most commonly in the management of OLP. However, the evidence base for the effectiveness of any therapy is weak. The objective of this thesis was to study novel aspects of OLP etiopathogenesis and management. An epidemiologic, retrospective case-control study was conducted to determine whether systemic diseases, in particular thyroid diseases, are associated with OLP. In addition, a randomized controlled trial comparing the effectiveness of topical tacrolimus, triamcinolone acetonide and placebo in symptomatic OLP was carried out. Furthermore, immunohistochemical expression of toll-like receptors 4 and 9, hyaluronan and its principal receptor CD44 antigen, hyaluronan synthases 1-3, hyaluronidases 1-2 and cathepsin K was studied in OLP tissue samples and in healthy oral mucosa. The effect of topical tacrolimus on the expression of these molecules in OLP was also studied. The results of the present study showed that a history of hypothyroidism was associated with an approximately twofold risk of having OLP. Furthermore, both tacrolimus and triamcinolone acetonide were more efficient than placebo in reducing the signs and symptoms of OLP. No statistically significant differences were noted in the efficacy between tacrolimus and triamcinolone acetonide. In addition, the expression of the studied molecules was altered in the epithelium or stroma in OLP compared to healthy oral mucosa. Tacrolimus treatment decreased the expression of CD44 antigen in the stroma and the expression of cathepsin K in the epithelium in OLP. In conclusion, the present study extends our knowledge about systemic associated factors and management of OLP. In addition, the results improve our understanding of molecular level changes that occur in OLP. / Tiivistelmä Suun punajäkälä on krooninen immuunivälitteinen limakalvotauti, jonka etiologia on tuntematon. Taudin syntymekanismiin liittyy tämän hetkisen näkemyksen mukaan T-soluvälitteisen immuniteetin aktivoituminen epiteelin keratinosyyttejä vastaan. Suun punajäkälä aiheuttaa osalle potilaista kivuliaita oireita ja lisää suusyövän riskiä. Parantavaa hoitoa tautiin ei ole. Yleisimmin suun punajäkälän oireiden hoidossa käytetään paikallisia kortikosteroidivalmisteita. Kuitenkin eri hoitomuotojen tehosta on vain heikkoa näyttöä. Tämän väitöskirjatyön tarkoituksena oli tutkia uusia näkökohtia liittyen suun punajäkälän etiopatogeneesiin ja hoitoon. Epidemiologisessa tapaus-verrokkitutkimuksessa selvitettiin, liittyvätkö yleissairaudet, erityisesti kilpirauhassairaudet, suun punajäkälään. Lisäksi satunnaistetussa kontrolloidussa tutkimuksessa verrattiin paikallisen takrolimuusin, triamsinoloniasetonidin ja lumelääkkeen tehoa oireisesta suun punajäkälästä kärsivillä potilailla. Tutkimuksessa selvitettiin myös tollin kaltaisten reseptorien 4 ja 9, hyaluronaanin ja sen pääasiallisen reseptorin CD44-antigeenin, hyaluronaanisyntaasien 1–3, hyaluronidaasien 1–2 sekä katepsiini K:n immunohistokemiallista ilmentymistä suun punajäkälänäytteissä ja terveessä suun limakalvossa. Lisäksi tutkittiin takrolimuusihoidon vaikutusta näiden molekyylien ilmentymiseen suun punajäkälässä. Tämän tutkimuksen tulokset osoittivat, että kilpirauhasen vajaatoimintaan liittyi noin kaksinkertainen riski sairastaa suun punajäkälää. Lisäksi havaittiin, että suun punajäkälässä sekä takrolimuusi että triamsinoloniasetonidi ovat tehokkaampia kuin lumelääke oireiden ja kliinisen taudinkuvan lievittämisessä. Takrolimuusin ja triamsinoloniasetonidin tehossa ei todettu tilastollisesti merkitseviä eroja. Lisäksi suun punajäkälänäytteissä tutkittujen molekyylien ilmentyminen oli muuttunut joko epiteelissä tai stroomassa verrattuna terveeseen limakalvoon. Takrolimuusihoito vähensi CD44-antigeenin ilmentymistä stroomassa ja katepsiini K:n ilmentymistä epiteelissä suun punajäkälässä. Yhteenvetona voidaan todeta, että tämä tutkimus lisää tietoa suun punajäkälään liittyvistä systeemisistä tekijöistä ja suun punajäkälän hoidosta. Lisäksi löydökset lisäävät ymmärtämystä suun punajäkälässä tapahtuvista molekyylitason muutoksista.
132

The role of stromal Hyaluronan in Malignant Melanoma Progression:: Investigation in a Has2-knockdown mouse model

Nguyen, Khiet Tam Christoph 16 August 2021 (has links)
Die vorliegende Arbeit befasst sich dem Glykosaminoglykan (GAG) Hyaluronan (HA) und dessen Einfluss auf die Entwicklung des malignen Melanoms (MM). Das in der extrazellulären Matrix (ECM) reichlich vorkommende HA wird schon seit dem späten 20. Jahrhundert genauerer im Zusammenhang mit der Tumorentwicklung untersucht. Gegensätzliche Eigenschaften von HA, die zum einen Tumore fördern und zum anderen ihnen entgegenwirken, wurden seither veröffentlicht. Allgemeiner Konsens ist, dass das HA-Molekulargewicht über die verschiedenen Effekte von HA entscheidet. Momentan ist jedoch nicht ausreichend belegt, wie HA auf das Tumorwachstum einwirkt und welche HA-Größen dies speziell begünstigen. Diese Untersuchung basiert auf einem in vivo Knockout von der Hyaluronan Synthase 2 (Has2) in der Maus, der die Produktion von hoch-molekulargewichtigen HA (HMW-HA) weitestgehend einschränkte. Das Wachstum vom experimentellem MM wurde in Abwesenheit der meisten HMW-HA untersucht. Diese Arbeit versuchte den Beweis zu erbringen, dass das lokale Wachstum und die Metastasenbildung der MM-Zellen abhängig von der vorhandenen HMW-HA in der Nähe des Tumors ist. Der Has2-knockout in der Mauslinie C57BL6 wurde verifiziert und nach einem veränderten Phänotyp der Mäuse untersucht. Obwohl nahezu dreiviertel der absoluten HA Menge durch den Knockout fehlte, zeigten die Mäuse keinen offensichtlichen Veränderungen. Erst eine Messung der Haut-Permeabilität deutete auf eine womöglich verstärkte Ausbildung der Stratum corneum hin. Eine direkte Auswirkung vom fehlendem HA auf das Tumorwachstum und der Metastasierungsrate konnte nicht ausreichend belegt werden. Das verwendete Mausmodell sowie die Wahl des experimentellen Tumors werden in dieser Arbeit kritisch diskutiert. Parallel durchgeführte in vitro Versuche mit teilweise artifiziellen 3D Matrizen, die unterschiedliche Mengen von HA enthielten, zeigten einen stärkeren Einfluss von niedermolekulare HA (LMW-HA) auf die Proliferation und Invasion von MM Zellen. Diese Beobachtungen stimmen mit dem derzeitigen Konsens überein, dass LMW-HA aktivierende Signaltransduktion auslöst und HMW-HA eher homöostatisch wirkt.:TABLE OF CONTENT Zusammenfassung Summary Table of content List of figures List of tables Abbreviations 1 Introduction 1.1 Structures of the skin 1.2 The malignant melanoma 1.3 The tumor microenvironment (TME) 1.4 Hyaluronan 1.4.1 HA Structure 1.4.2 HA anabolism 1.4.3 HA catabolism 1.4.4 HA binding proteins 1.4.5 HA cell surface receptors 1.5 Hyaluronan in malignant melanoma 1.6 Aim of the thesis 2 Methods 2.1 Murine malignant melanoma cell lines 2.2 Inducible Has2-knockout mice 2.2.1 The Cre/loxP System 2.2.2 Genetical modification for the Has2-knockout 2.2.3 4-Hydroxytamoxifen induction of knockout 2.2.4 Experimental tumor model in mouse 2.2.5 Intravenous tumor injection 2.3 Primary Has2-knockout fibroblasts for in vitro experiments 2.3.1 Isolation of primary fibroblast from mouse skin tissue 2.3.2 Induction of Has2-ko fibroblasts 2.4 Molecular analysis 2.4.1 PCR analysis of genome DNA 2.4.2 Quantification of gene expression 2.4.3 Microarray analysis 2.4.4 Quantification of Has2 protein levels 2.4.5 Quantification of HA 2.4.6 HA size analysis by agarose gel electrophoresis 2.5 Physical analysis of the skin 2.5.1 Skin elasticity measurement 2.5.2 Skin permeability measurement 2.5.3 Skin hydration and TEWL measurement 2.6 Histological analysis 2.6.1 Cryo-fixed samples 2.6.2 Immunofluorescence staining 2.6.3 FFPE samples 2.6.4 HA staining 2.6.5 Histochemical images 2.7 Physiological analysis of MM cell proliferation with BrdU-Assay 2.8 Statistical analysis 3 Materials 3.1 Mouse lines 3.2 Cell lines 3.3 Buffer and solution recipes 3.4 Chemicals 3.5 Molecular-biological reagents and enzymes 3.6 Primers 3.7 Antibodies 3.8 Kits 3.9 Devices and tools 3.10 Disposables 3.11 Software 4 Results 4.1 The Has2-knockout mouse model 4.1.1 Has2-knockout characterization 4.1.2 Incomplete Has2 deletion 4.1.3 Effects of the HA knockdown 4.1.4 Has2-knockout efficiency in other organs 4.1.5 Effects of Has2-knockout on gene expression 4.2 In vitro Has2-knockout and effect on MM cells 4.2.1 In vitro Has2- and HA-knockdown 4.2.2 Has2-ko fibroblast conditioned media decreased MM proliferation 4.2.3 MM conditioned media influenced fibroblast’s HA secretion 4.2.4 The transition towards in vivo tumor experiments 4.3 In vivo Tumor experiments 4.3.1 HA threshold, correlation, and exclusions 4.3.2 Effects of HA knockdown on primary tumor volume and weight 4.3.3 Tumor histology and HA localization 4.3.4 HA fragments in tumors, healthy-, and tumor-related-skin samples 4.3.5 Metastasis formation 5 Discussion 5.1 HA knockdown 5.2 HA knockdown phenotype 5.2.1 Skin stiffness 5.2.2 Skin water homeostasis 5.3 Paracrine interactions between MM and fibroblasts 5.4 HA thresholding 5.5 Tumor readouts 5.6 In vitro ECM models 5.7 Metastasis 5.8 Alternative tumor models with stronger stromal interaction 5.9 The presented results considering current HA-Tumor research 6 Conclusion 7 Literature Danksagung Lebenslauf Akademischer Werdegang Stipendium und Auszeichnung Publikation und Posterpräsentation Publikationen Vorträge und Posterpräsentationen Eigenständigkeitserklärung / The present work addresses the glycosaminoglycan (GAG) hyaluronan (HA) and its influence on the development of malignant melanoma (MM). HA, which is abundant in the extracellular matrix (ECM), has been studied closely in relation to tumor development since the late 20th century. Opposing properties of HA, on the one hand promoting tumors and the other hand counteracting them, have since been published. The general consensus is that HA molecular weight determines the various effects of HA. However, there is insufficient evidence on how HA affects tumor growth and which HA sizes specifically promote it. This study is based on an in vivo knockout of hyaluronan synthase 2 (Has2) in mice, which largely restricted the production of high molecular weight HA (HMW-HA). Growth from experimental MM was examined in the absence of most HMW-HA. This work sought to provide evidence that local growth and metastasis of MM cells is dependent on the presence of HMW-HA in the vicinity of the tumor. Has2 knockout in the mouse line C57BL6 was verified and examined for an altered phenotype of the mice. Although nearly three-quarters of the absolute HA amount was absent due to the knockout, the mice showed no obvious change. Only a measurement of skin permeability indicated a possible increased barrier function of the stratum corneum. A direct effect of the lack of HA on tumor growth and metastasis rate could not be sufficiently demonstrated. The applied mouse model and the choice of experimental tumor are critically discussed in this work. Parallel in vitro experiments with partially artificial 3D matrices containing different amounts of HA showed a stronger influence of low molecular weight HA (LMW-HA) on proliferation and invasion of MM cells. These observations are consistent with the emerging consensus that LMW-HA triggers activating signal transduction and HMW-HA is more homeostatic.:TABLE OF CONTENT Zusammenfassung Summary Table of content List of figures List of tables Abbreviations 1 Introduction 1.1 Structures of the skin 1.2 The malignant melanoma 1.3 The tumor microenvironment (TME) 1.4 Hyaluronan 1.4.1 HA Structure 1.4.2 HA anabolism 1.4.3 HA catabolism 1.4.4 HA binding proteins 1.4.5 HA cell surface receptors 1.5 Hyaluronan in malignant melanoma 1.6 Aim of the thesis 2 Methods 2.1 Murine malignant melanoma cell lines 2.2 Inducible Has2-knockout mice 2.2.1 The Cre/loxP System 2.2.2 Genetical modification for the Has2-knockout 2.2.3 4-Hydroxytamoxifen induction of knockout 2.2.4 Experimental tumor model in mouse 2.2.5 Intravenous tumor injection 2.3 Primary Has2-knockout fibroblasts for in vitro experiments 2.3.1 Isolation of primary fibroblast from mouse skin tissue 2.3.2 Induction of Has2-ko fibroblasts 2.4 Molecular analysis 2.4.1 PCR analysis of genome DNA 2.4.2 Quantification of gene expression 2.4.3 Microarray analysis 2.4.4 Quantification of Has2 protein levels 2.4.5 Quantification of HA 2.4.6 HA size analysis by agarose gel electrophoresis 2.5 Physical analysis of the skin 2.5.1 Skin elasticity measurement 2.5.2 Skin permeability measurement 2.5.3 Skin hydration and TEWL measurement 2.6 Histological analysis 2.6.1 Cryo-fixed samples 2.6.2 Immunofluorescence staining 2.6.3 FFPE samples 2.6.4 HA staining 2.6.5 Histochemical images 2.7 Physiological analysis of MM cell proliferation with BrdU-Assay 2.8 Statistical analysis 3 Materials 3.1 Mouse lines 3.2 Cell lines 3.3 Buffer and solution recipes 3.4 Chemicals 3.5 Molecular-biological reagents and enzymes 3.6 Primers 3.7 Antibodies 3.8 Kits 3.9 Devices and tools 3.10 Disposables 3.11 Software 4 Results 4.1 The Has2-knockout mouse model 4.1.1 Has2-knockout characterization 4.1.2 Incomplete Has2 deletion 4.1.3 Effects of the HA knockdown 4.1.4 Has2-knockout efficiency in other organs 4.1.5 Effects of Has2-knockout on gene expression 4.2 In vitro Has2-knockout and effect on MM cells 4.2.1 In vitro Has2- and HA-knockdown 4.2.2 Has2-ko fibroblast conditioned media decreased MM proliferation 4.2.3 MM conditioned media influenced fibroblast’s HA secretion 4.2.4 The transition towards in vivo tumor experiments 4.3 In vivo Tumor experiments 4.3.1 HA threshold, correlation, and exclusions 4.3.2 Effects of HA knockdown on primary tumor volume and weight 4.3.3 Tumor histology and HA localization 4.3.4 HA fragments in tumors, healthy-, and tumor-related-skin samples 4.3.5 Metastasis formation 5 Discussion 5.1 HA knockdown 5.2 HA knockdown phenotype 5.2.1 Skin stiffness 5.2.2 Skin water homeostasis 5.3 Paracrine interactions between MM and fibroblasts 5.4 HA thresholding 5.5 Tumor readouts 5.6 In vitro ECM models 5.7 Metastasis 5.8 Alternative tumor models with stronger stromal interaction 5.9 The presented results considering current HA-Tumor research 6 Conclusion 7 Literature Danksagung Lebenslauf Akademischer Werdegang Stipendium und Auszeichnung Publikation und Posterpräsentation Publikationen Vorträge und Posterpräsentationen Eigenständigkeitserklärung
133

Biokompatibilní amfifilní látky v interakcích s polymery / Biocompatible Amphiphilic Compounds and their Interactions with Polymers

Burdíková, Jana January 2018 (has links)
This work is focused on the study of interaction between hyaluronan and high-biocompatible amphiphilic molecules. Using fluorescent probe method, screening of the interaction of cationic lipid 1,2-dipalmitoyl-3-trimethylammonium-propane (DPTAP), mixture of this cationic lipid with zwitterionic lipid, 1,2-dipalmitoyl-sn-glycero-3-phosphochloline (DPPC), with hyaluronan, both native and hydrophobically modified was carried out. Results showed the self-aggregation of DPPC and DPTAP independently on lipids ratio in the mixture and the interaction of DPTAP and DPPC/DPTAP aggregates with hyaluronan at specific ratio of DPTAP and hyaluronan concentration. Physical properties of formed membranes and the influence of cholesterol were also investigated at different DPPC and DPTAP concentration ratio. Last but not least, the non-ionic surfactant-DPPC systems were studied, namely, the size of the formed aggregates, the thermodynamics of solubilisation and the interaction with native hyaluronan.
134

Hyaluronan hydrogels / Hyaluronan hydrogels

Vaculíková, Hana January 2019 (has links)
In this thesis there was preparation optimized for agarose-gelatin hydrogels with addition of various concentrations of low-molecular and high-molecular hyaluronan and than there were examined viscoelastic properties of them by rheological oscilation tests and high-resolution ultrasonic spektrometry. By rheology were measured values of elastic and viscous modulus for selected amplitude of strain, oscilation frequencies and temperatures. In the second method there were recorded values of ultrasonic velocities of samples at temperature scanning from 85 to 25 °C and from 25 to 85 °C in HR-US 102, which were compared with ultrasonic velocities measured at the temperature 27,0±0,5 °C by gel-modul HR-EX-SSC.
135

Vývoj materiálu na bázi hydrogelů kyseliny hyaluronové pro regeneraci myokardu / Development of Material Based on Hyaluronic Acid s Hydrogels for Myocardial Regeneration

Kovářová, Lenka January 2020 (has links)
The thesis is focused on material development based on hyaluronic acid usable in regenerative medicine, especially for heart tissue regeneration after myocardial infarction. The object of the study is the oxidized form of hyaluronic acid (HA-Ox) and hydroxyphenyl derivative of HA (HA-TA). HA-Ox can be crosslinked with a bifunctional alkoxyamine POA and HA-TA undergoes an enzymatic reaction in the presence of hydrogen peroxide catalysed by horseradish peroxidase leading to gel formation. To describe the materials, chemical and physical properties, gelation kinetics and conditions of crosslinking reactions were studied. Hydrogels were characterized by mechanical and viscoelastic properties, degradability or stability in simulated body fluids. These hydrogels serve as scaffolds for the selected cell type. To promote cell adhesion and viability, an RGD sequence has been bonded to the structure of HA-TA. This resulting material is also compatible with selected applicators. Its viscosity and extrusion force are low enough to allow application with a catheter with a very small internal diameter. The applicability of the material through the supply tube to the hydrogel reservoir of the second SPREADS device showed good homogeneity, cell distribution and viability. Finally, the material was applied in vivo using these devices during a preclinical study.
136

Fyzikální hydrogely na bázi biopolymerů a tenzidů / Physical hydrogels based on biopolymers and surfactants

Velcer, Tomáš January 2021 (has links)
This doctoral thesis studies the properties and behaviour of phase-separated hydrogels. These can be prepared by interaction of polyelectrolytes with oppositely charged surfactants. Negatively charged polysaccharide hyaluronan and cationic surfactant carbethopendecinium bromide (Septonex), whose properties, behaviour and utilization are described in the first two chapters of theoretical part, were selected for this role. Hyaluronan is naturally-occuring in living organisms and is known for his specific targeting to the tumour cells. Septonex is used as antiseptic and disinfectant. Experimental part of this work is focused on examination of the structure and behaviour of these types of hydrogels especially from rheological point of view. The crucial part of this study was to establish mechanical properties and their dependence on environment. This led to design further studies. Structural analysis was held using the methods of ATR-FTIR, ionic chromatography and ICP-OES helping to measure the inner content of entry materials in the gels and supernatants respectively. The last chapter deals with antimicrobial activity. The results of this study indicate a potential usage of these substances in the field of medical applications.
137

Fluorescence ve výzkumu hydrofilních oblastí asociativních koloidů / Fluorescence study of hydrophilic domains of associating colloids

Londinová, Monika January 2008 (has links)
The properties of the hyaluronan were investigated by using different fluorescence probes, because hyaluronan is a hopeful carrier of an active matter in medicine and cosmetics. Selected fluorescence probes were: cationic acridine orange, Nile Blue A, methylene blue, amphiphilic 4-Di-2-ASP and anionic fluorescein. Except from fluorescence and absorption spectra of the probes were observed electrostatic and hydrophobic interactions as well. The probes in solvents with different polarity (MeOH, EtOH, DMSO) showed the bathochromic shift in the emission maximum and quenching of the fluorescence with the increasing polarity of the solvents. The influence of the ionic strength on fluorescence properties of the probe acridine orange and 4-Di-2-ASP was investigated in aqueous solutions of chlorides. The formation of acridine orange dimer is inhibited with increasing ionic strength. CaCl2 increased the ionic strength the most, then prevented repulsion of carboxylate groups, so it means the expansion of hyaluronan cluster into the solution. However, the emission of the probe 4-Di-2-ASP was quenched with the addition of CaCl2 the most. The first additions of COO– groups cause the formation of dimers of AO shown as decreasing in extinction coefficient and fluorescence intensity. Next addition of the hyaluronan caused a depolymerization of formed dimers and the increase of the emission intensity. The repolymerization caused the decrease and then again the increase. In case of 4-Di-2-ASP was the pattern of the fluorescence (the intensity and the position of the emission) firstly the same, but at the concentration of 1 g dm-3 the emission intensity increased. The probes MB and F were used for spectroscopic studies of the interaction between methylene blue-fluorescein complex and anionic and cationic surfactants. The absorbance of separate MB and F changed only with the addition of surfactants with the opposite electric charge. Absorbance of the mixture MB-F changed with the addition of the CTAC surfactant, while the addition of SDS into the mixture caused only the change of MB absorption spectra.
138

Studium interakcí polyelektrolytů s kladně nabitými dusíkatými amfifilními látkami / Investigation of Polyelectrolytes Interactions with Cationic Aminogroups-containing Amphiphiles

Zeman, Jan January 2013 (has links)
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.
139

Fosfolipidy jako základ biodegradabilních nosičových systémů / Phospholipids as the basis of biodegradable delivery systems

Burdíková, Jana January 2013 (has links)
This thesis is focused on investigation of phospholipid-hyaluronan system. First, appropriate method for preparation of bulk solution of phospholipid/lipid and suitable fluorescence probe were chosen. Sonification was selected as a method for preparation of bulk solution and pyrene was chosen as a fluorescence probe. From the group of phospholipids lecithin was selected. Next to phospholipid, lipid with no phosphate group (DPTAP) was utilized for comparison, alternatively a mixture of lipid (DPTAP) and phospholipid (DPPC). Instead of hyaluronan another polyelectrolytes (sodium polystyrene sulfonate, sodium alginate) were used too. Measurements were performed in water environment and in phosphate buffer saline (PBS). All investigation was accomplished by fluorescence spectroscopy and dynamic light scattering.
140

Studium interakcí hyaluronan-tenzidy dialyzační technikou / Dialysis study of hyaluronan-surfactant interactions

Šejnohová, Michaela January 2014 (has links)
This diploma thesis is concentrated on the interactions between polyelectrolyte (hyaluronan) and cationic surfactant (CTAB). The experiments were performed in an aqueous solution and in an environment of physiological ionic strength (0,15mmoldm-3 NaCl). The determination of the surfactant concentration in solutions was based on the formation of colored complexes of CTAB and picric acid in chloroform. The concentrations of surfactant were measured by UV-VIS spectroscopy. The stability of CTAB+HyA was examined by a dialysis method. The results showed that, regardless of the environment, the presence of HyA in solution reduces the number of free molecules of CTAB which can be determined in the sample. It has been proved that there is an interaction between HyA and surfactant and that CTAB has greater affinity for HyA then for the picric acid. The stability of CTAB+HyA was determined by dialysis of 120 hours. After that time, the concentrations of the retentate and permeate were settled. The results showed that in the membrane remains a certain amount of CTAB bounded to hyaluronan. The system can be suitable for the preparation of targeted carriers of biologically active substances.

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