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Drop coating deposition Raman spectroscopy of liposomes with different compositions
Antalík, Andrej ; Kočišová, Eva (advisor) ; Holoubek, Aleš (referee)
Method of drop-coating deposition Raman spectroscopy is a special tech- nique that employs deposition of a small droplet of the sample on a hydro- phobic surface with subsequent solvent removal by evaporation. As a result the concentrated material forms a ring at the edge of the droplet. This techni- que has proven to be efficient for liposome studies at low concentrations. We focused on a study of spectral changes and ring formation in phosphatidylcho- line liposomes due to increasing amount of cholesterol. Higher concentration of cholesterol didn't cause significant changes in membrane structure, such as phase transition, however the ring wasn't formed. Second part of this bache- lor thesis concerns with the search for some alternative surface to previously used SpectRIM TM DCDR plates made by Tienta Sciences, Inc. which are no longer available. The polished calcium fluoride glass (CaF2) seems to be the most suitable for the further use from all tested surfaces. Raman signal at the other surfaces was either weak or spectral bands that don't belong to lipid were observed.
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Influence of the surface hydrophobicity and charge of the molecule for drop coating deposition Raman spectroscopy
Bura, Radek ; Kočišová, Eva (advisor) ; Procházka, Marek (referee)
Raman spectroscopy is an optical vibrational spectroscopic technique suited for a study of biomolecules and their interactions. In contrast to classical Raman spectroscopy, Drop-Coating Deposition Raman spectroscopy (DCDR) enables due to a preconcentration of the sample dried on a special hydrophobic surface to acquire a high-quality spectrum even in case of low concentrated samples. In collaboration with Department of Macromolecular Physics of the Faculty of Mathematics and Physics at Charles University, the three special surfaces - substrates - with different wettability (hydrophobicity) and roughness on the basis of silvers nanoparticles have been prepared. Solutions of methylene blue and glutamic acid at different concentrations and pH were dropped on these substrates. Nanoparticles size was determined. It was shown, that with increasing number of sputtered nanoparticles, the roughness of the substrates increased also. More roughened substrates show a higher static contact angle. The dynamics of droplet drying and the preconcentration of substances in the dried deposit were monitored. The preconcentration was assessed from the first subspectrum obtained from a factor analysis performed on series of measured Raman spectra from dried deposits. There was none among the substrates on which there would...
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Interakce liposomů s porfyriny studována pomocí Ramanovy spektroskopie kapkově nanášených povlaků
Vaculčiaková, Lenka ; Kočišová, Eva (advisor) ; Holoubek, Aleš (referee)
Water-soluble cationic porphyrins have been studied in relation to antisense therapy and they have been successfully used to enhance the delivery of oligonu- cleotides to cells. The main focus of this study was to characterize the mech- anism of interaction of liposomes as model membranes, and porphyrins. We applied the drop coating deposition Raman spectroscopy (DCDR) to study com- plexes of liposomes and porphyrins. DCDR allowed us to measure complexes of low concentration as it uses the 'coffee ring' effect to concentrate the sample at the edge of a drop. We studied four different complexes combined of lipids: 1, 2−dipalmitoyl−sn−glycero−3−phosphocholine, 1, 2−dioleoyl−sn−glycero− 3 − phospho − (1 − rac − glycerol) and metalloporphyrins: copper 5, 10, 15, 20 − tetrakis(1 − methyl − 4 − pyridyl)porphyrin, copper 5, 10, 15, 20 − tetrakis(4 − sulfonatophenyl)porphyrin. We have found that the way these two components interact strongly depends on a specific lipid and porphyrin used. We observed partial incorporation of porphyrins into the liposome bilayer, their localisation to the surface of the liposome or the change of the conformation and ordering of lipid molecules. Moreover, we have found that the distribution of porphyrins in the dried drop is randomly non-homogenous. 61
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Drop coating deposition Raman spectroscopy of liposomes with different compositions
Antalík, Andrej ; Kočišová, Eva (advisor) ; Holoubek, Aleš (referee)
Method of drop-coating deposition Raman spectroscopy is a special tech- nique that employs deposition of a small droplet of the sample on a hydro- phobic surface with subsequent solvent removal by evaporation. As a result the concentrated material forms a ring at the edge of the droplet. This techni- que has proven to be efficient for liposome studies at low concentrations. We focused on a study of spectral changes and ring formation in phosphatidylcho- line liposomes due to increasing amount of cholesterol. Higher concentration of cholesterol didn't cause significant changes in membrane structure, such as phase transition, however the ring wasn't formed. Second part of this bache- lor thesis concerns with the search for some alternative surface to previously used SpectRIM TM DCDR plates made by Tienta Sciences, Inc. which are no longer available. The polished calcium fluoride glass (CaF2) seems to be the most suitable for the further use from all tested surfaces. Raman signal at the other surfaces was either weak or spectral bands that don't belong to lipid were observed.
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