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Agregation of palmitoyl-modified hyaluronan
Lehocká, Nikola ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
This thesis deals with the aggregation behaviour of palmitoylhyaluronan in two degrees of substitution, namely 10 % and 16 %. Using a fluorescence spectroscopy method with pyrene as a fluorescence probe, we found a critical micellar concentration. The results were confirmed by measuring the dynamic light scattering, which also showed an increase in the size of aggre-gates with an increasing concentration. System stability is reduced by increased ionic strength as evidenced by zeta potential measurement. Experiments found that 16 % substitution sample can form a gel. The gel is very stiff and has excellent properties, which was confirmed by rhe-ology. We also managed to incorporate pyrene in the gel, which was demonstrated by the presence of highly solvated domains that could be polymer micelles. Based on these results, 16% substitution sample was subjected the MTT assay to cytotoxicity. The results confirmed that the examined sample was not toxic.
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Nanocarriers based on hydrophobized biopolymer
Velcer, Tomáš ; Hnyluchová, Zuzana (referee) ; Venerová, Tereza (advisor)
This work studies the properties of hydrophobically modified biopolymers for potential use in targeted drug delivery. Two samples of hydrophobically modified hyaluronan were selected. The critical micelle concentration (CMC) of these samples was measured using fluorescence spectroscopy, wherein it was found that micelle formation occurs over a wide concentration region. Environment of 0,15 M NaCl causes the decrease of CMC only slightly or not at all. Using the method of dynamic light scattering, particle size was measured. One of the samples exhibited a double size distribution. DLS results are consistent with the results of fluorescence spectroscopy at issue in aggregates forming near the CMC point. Zeta potential measurements provide information about stability of the samples. The results of this study confirm that one of the studied samples seems to be a suitable candidate for the post of drug carrier for targeted delivery.
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Colloidal particles marked with biopolymer
Pihíková, Dominika ; Víteček,, Jan (referee) ; Mravec, Filip (advisor)
The effect of hydrophobically modified hyaluronan on surfactants aggregation has been studied in this master’s thesis. The value of critical micelle concentration of anionic surfactant SDBS (sodium dodecylbenzensulfonate), cationic surfactant CTAB (cetyltrimethylamonnium bromide) and nonionic surfactant Triton X-100 (octylphenol ethoxylate) was determined by fluorescence spectroscopy using pyrene probe. Aggregation behavior of surfactants was performed with addition of hydrophobically modified hyaluronan of two molecular weights (17 kDa, 206 kDa) in aqueous solution. The greatest influence of hydrophobized hyaluronan on aggregation behavior was observed in system with cationic surfactant CTAB. Stability of system containing cationic surfactant and hydrophobically modified hyaluronan was established through zeta potential. Last part of thesis deals with size determination using dynamic light scattering.
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Gelation of hydrophobized hyaluronan
Gruberová, Eliška ; Venerová, Tereza (referee) ; Pekař, Miloslav (advisor)
This diploma thesis deals with hyaluronan modified by palmitoyl and its gelation. Gels were created from palmitoyl hyaluronan with molecular weight 216 kDa and degree of substitution 11 % in concentrations 15 and 20 g dm-3 in water and concentrations 10, 15, 20 g dm-3 in NaCl and TSB. Also gel from palmitoyl hyaluronan with molecular weight 35 kDa and degree of substitution 10 % in concentrations 20, 30 g dm-3 in NaCl was created. Gels were investigated concerning medical applications. Gels were rigid and had very good properties, which was confirmed by rheology. The physical properties (pH, water content) of gels and stability were investigated. On the grounds of the MTT test, three methods of cell incorporation were suggested. Gels are nontoxic, biocompatible, and biodegradable with nontoxic degradation products and that is why they are excellent aspirants for use in biomedicine.
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Gelation of hydrophobized hyaluronan
Gruberová, Eliška ; Venerová, Tereza (referee) ; Pekař, Miloslav (advisor)
This diploma thesis deals with hyaluronan modified by palmitoyl and its gelation. Gels were created from palmitoyl hyaluronan with molecular weight 216 kDa and degree of substitution 11 % in concentrations 15 and 20 g dm-3 in water and concentrations 10, 15, 20 g dm-3 in NaCl and TSB. Also gel from palmitoyl hyaluronan with molecular weight 35 kDa and degree of substitution 10 % in concentrations 20, 30 g dm-3 in NaCl was created. Gels were investigated concerning medical applications. Gels were rigid and had very good properties, which was confirmed by rheology. The physical properties (pH, water content) of gels and stability were investigated. On the grounds of the MTT test, three methods of cell incorporation were suggested. Gels are nontoxic, biocompatible, and biodegradable with nontoxic degradation products and that is why they are excellent aspirants for use in biomedicine.
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|
|
Agregation of palmitoyl-modified hyaluronan
Lehocká, Nikola ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
This thesis deals with the aggregation behaviour of palmitoylhyaluronan in two degrees of substitution, namely 10 % and 16 %. Using a fluorescence spectroscopy method with pyrene as a fluorescence probe, we found a critical micellar concentration. The results were confirmed by measuring the dynamic light scattering, which also showed an increase in the size of aggre-gates with an increasing concentration. System stability is reduced by increased ionic strength as evidenced by zeta potential measurement. Experiments found that 16 % substitution sample can form a gel. The gel is very stiff and has excellent properties, which was confirmed by rhe-ology. We also managed to incorporate pyrene in the gel, which was demonstrated by the presence of highly solvated domains that could be polymer micelles. Based on these results, 16% substitution sample was subjected the MTT assay to cytotoxicity. The results confirmed that the examined sample was not toxic.
|
|
|
Colloidal particles marked with biopolymer
Pihíková, Dominika ; Víteček,, Jan (referee) ; Mravec, Filip (advisor)
The effect of hydrophobically modified hyaluronan on surfactants aggregation has been studied in this master’s thesis. The value of critical micelle concentration of anionic surfactant SDBS (sodium dodecylbenzensulfonate), cationic surfactant CTAB (cetyltrimethylamonnium bromide) and nonionic surfactant Triton X-100 (octylphenol ethoxylate) was determined by fluorescence spectroscopy using pyrene probe. Aggregation behavior of surfactants was performed with addition of hydrophobically modified hyaluronan of two molecular weights (17 kDa, 206 kDa) in aqueous solution. The greatest influence of hydrophobized hyaluronan on aggregation behavior was observed in system with cationic surfactant CTAB. Stability of system containing cationic surfactant and hydrophobically modified hyaluronan was established through zeta potential. Last part of thesis deals with size determination using dynamic light scattering.
|
|
|
Nanocarriers based on hydrophobized biopolymer
Velcer, Tomáš ; Hnyluchová, Zuzana (referee) ; Venerová, Tereza (advisor)
This work studies the properties of hydrophobically modified biopolymers for potential use in targeted drug delivery. Two samples of hydrophobically modified hyaluronan were selected. The critical micelle concentration (CMC) of these samples was measured using fluorescence spectroscopy, wherein it was found that micelle formation occurs over a wide concentration region. Environment of 0,15 M NaCl causes the decrease of CMC only slightly or not at all. Using the method of dynamic light scattering, particle size was measured. One of the samples exhibited a double size distribution. DLS results are consistent with the results of fluorescence spectroscopy at issue in aggregates forming near the CMC point. Zeta potential measurements provide information about stability of the samples. The results of this study confirm that one of the studied samples seems to be a suitable candidate for the post of drug carrier for targeted delivery.
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