TY - JOUR A1 - Tzoneva, Rumiana A1 - Stoyanova, Tihomira A1 - Petrich, Annett A1 - Popova, Desislava A1 - Uzunova, Veselina A1 - Momchilova, Albena A1 - Chiantia, Salvatore T1 - Effect of Erufosine on Membrane Lipid Order in Breast Cancer Cell Models JF - Biomolecules N2 - Alkylphospholipids are a novel class of antineoplastic drugs showing remarkable therapeutic potential. Among them, erufosine (EPC3) is a promising drug for the treatment of several types of tumors. While EPC3 is supposed to exert its function by interacting with lipid membranes, the exact molecular mechanisms involved are not known yet. In this work, we applied a combination of several fluorescence microscopy and analytical chemistry approaches (i.e., scanning fluorescence correlation spectroscopy, line-scan fluorescence correlation spectroscopy, generalized polarization imaging, as well as thin layer and gas chromatography) to quantify the effect of EPC3 in biophysical models of the plasma membrane, as well as in cancer cell lines. Our results indicate that EPC3 affects lipid–lipid interactions in cellular membranes by decreasing lipid packing and increasing membrane disorder and fluidity. As a consequence of these alterations in the lateral organization of lipid bilayers, the diffusive dynamics of membrane proteins are also significantly increased. Taken together, these findings suggest that the mechanism of action of EPC3 could be linked to its effects on fundamental biophysical properties of lipid membranes, as well as on lipid metabolism in cancer cells. KW - alkylphospholipids KW - fluorescence microscopy KW - fluorescence correlation spectroscopy KW - lipids KW - plasma membrane KW - cancer KW - lipid–lipid interactions KW - membrane microdomains KW - membrane biophysics Y1 - 2020 U6 - https://doi.org/10.3390/biom10050802 SN - 2218-273X VL - 10 IS - 5 PB - MDPI CY - Basel ER - TY - GEN A1 - Tzoneva, Rumiana A1 - Stoyanova, Tihomira A1 - Petrich, Annett A1 - Popova, Desislava A1 - Uzunova, Veselina A1 - Albena, Momchilova A1 - Chiantia, Salvatore T1 - Effect of Erufosine on Membrane Lipid Order in Breast Cancer Cell Models T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Alkylphospholipids are a novel class of antineoplastic drugs showing remarkable therapeutic potential. Among them, erufosine (EPC3) is a promising drug for the treatment of several types of tumors. While EPC3 is supposed to exert its function by interacting with lipid membranes, the exact molecular mechanisms involved are not known yet. In this work, we applied a combination of several fluorescence microscopy and analytical chemistry approaches (i.e., scanning fluorescence correlation spectroscopy, line-scan fluorescence correlation spectroscopy, generalized polarization imaging, as well as thin layer and gas chromatography) to quantify the effect of EPC3 in biophysical models of the plasma membrane, as well as in cancer cell lines. Our results indicate that EPC3 affects lipid–lipid interactions in cellular membranes by decreasing lipid packing and increasing membrane disorder and fluidity. As a consequence of these alterations in the lateral organization of lipid bilayers, the diffusive dynamics of membrane proteins are also significantly increased. Taken together, these findings suggest that the mechanism of action of EPC3 could be linked to its effects on fundamental biophysical properties of lipid membranes, as well as on lipid metabolism in cancer cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1000 KW - alkylphospholipids KW - fluorescence microscopy KW - fluorescence correlation spectroscopy KW - lipids KW - plasma membrane KW - cancer KW - lipid–lipid interactions KW - membrane microdomains KW - membrane biophysics Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-477056 SN - 1866-8372 IS - 1000 ER - TY - THES A1 - Knigge, Xenia T1 - Einzelmolekül-Manipulation mittels Nano-Elektroden und Dielektrophorese T1 - Single molecule manipulation using nano-electrodes and dielectrophoresis N2 - In dieser Arbeit wurden Nano-Elektroden-Arrays zur Einzel-Objekt-Immobilisierung mittels Dielektrophorese verwendet. Hierbei wurden fluoreszenzmarkierte Nano-Sphären als Modellsystem untersucht und die gewonnenen Ergebnisse auf biologische Proben übertragen. Die Untersuchungen in Kombination mit verschiedenen Elektrodenlayouts führten zu einer deterministischen Vereinzelung der Nano-Sphären ab einem festen Größenverhältnis zwischen Nano-Sphäre und Durchmesser der Elektrodenspitzen. An den Proteinen BSA und R-PE konnte eine dielektrophoretische Immobilisierung ebenfalls demonstriert und R-PE Moleküle zur Vereinzelung gebracht werden. Hierfür war neben einem optimierten Elektrodenlayout, das durch Feldsimulationen den Feldgradienten betreffend gesucht wurde, eine Optimierung der Feldparameter, insbesondere von Spannung und Frequenz, erforderlich. Neben der Dielektrophorese erfolgten auch Beobachtungen anderer Effekte des elektrischen Feldes, wie z.B. Elektrolyse an Nano-Elektroden und Strömungen über dem Elektroden-Array, hervorgerufen durch Joulesche Wärme und AC-elektroosmotischen Fluss. Zudem konnte Dielektrophorese an Silberpartikeln beobachtet werden und mittels Fluoreszenz-, Atom-Kraft-, Raster-Elektronen-Mikroskopie und energiedispersiver Röntgenspektroskopie untersucht werden. Schließlich wurden die verwendeten Objektive und Kameras auf ihre Lichtempfindlichkeit hin analysiert, so dass die Vereinzelung von Biomolekülen an Nano-Elektroden nachweisbar war. Festzuhalten bleibt also, dass die Vereinzelung von Nano-Objekten und Biomolekülen an Nano-Elektroden-Arrays gelungen ist. Durch den parallelen Ansatz erlaubt dies, Aussagen über das Verhalten von Einzelmolekülen mit guter Statistik zu treffen. N2 - In this work, nanoelectrode arrays were used for single object immobilization by dielectrophoresis. Fluorescently labeled nanospheres were used as a model system and the results were transferred to biological samples. The experiments in combination with different electrode layouts led to a deterministic singling of the nanospheres for a fixed size ratio between nanosphere and tipdiameter. Dielectrophoretic immobilization could also be demonstrated for the proteins BSA and R-PE, while R-PE molecules were even immobilized as single objects. For this purpose, in addition to an optimized electrode layout, which was searched by numerical field calculations, an optimization of the field parameters was required, in particular of voltage and frequency. Besides dielectrophoresis, observations of other effects were made, e.g. electrolysis at nanoelectrodes and fluid flows caused by Joule heating and AC-electroosmotic flow. In addition, dielectrophoresis was observed on silver nanoparticles, which was examined by fluorescence-, atomic force-, scanning electron microscopy and energy dispersive X-ray spectroscopy. Finally, the objectives and cameras were analyzed for their photosensitivity so that the singling of biomolecules on nanoelectrodes became detectable. The successful singling of nanoobjects and biomolecules on nanoelectrodes has been shown in a parallel approach so that it is possible to make statements about the behavior of single molecules with good statistics. KW - Dielektrophorese KW - Einzelmolekül-Biosensor KW - parallele Immobilisierung von Biomolekülen KW - R-PE KW - Polystyrol Nano-Sphären KW - Nano-Elektroden KW - 3D-Feldsimulationen KW - Einzel-Objekt-Nachweis KW - Fluoreszenz-Mikroskopie KW - REM KW - dielectrophoresis KW - single-molecule biosensor KW - parallel immobilization of biomolecules KW - R-PE KW - polystyrene nano-spheres KW - nano-electrodes KW - 3D field calculations KW - single-object detection KW - fluorescence microscopy KW - SEM Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-443137 ER -