@article{GrebinykPrylutskaChepurnaetal.2019, author = {Grebinyk, Anna and Prylutska, Svitlana and Chepurna, Oksana and Grebinyk, Sergii and Prylutskyy, Yuriy and Ritter, Uwe and Ohulchanskyy, Tymish Y. and Matyshevska, Olga and Dandekar, Thomas and Frohme, Marcus}, title = {Synergy of Chemo- and Photodynamic Therapies with C60 Fullerene-Doxorubicin Nanocomplex}, series = {Nanomaterials}, volume = {9}, journal = {Nanomaterials}, number = {11}, publisher = {MDPI}, issn = {2079-4991}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-12940}, year = {2019}, abstract = {A nanosized drug complex was explored to improve the efficiency of cancer chemotherapy, complementing it with nanodelivery and photodynamic therapy. For this, nanomolar amounts of a non-covalent nanocomplex of Doxorubicin (Dox) with carbon nanoparticle C60 fullerene (C60) were applied in 1:1 and 2:1 molar ratio, exploiting C60 both as a drug-carrier and as a photosensitizer. The fluorescence microscopy analysis of human leukemic CCRF-CEM cells, in vitro cancer model, treated with nanocomplexes showed Dox's nuclear and C60's extranuclear localization. It gave an opportunity to realize a double hit strategy against cancer cells based on Dox's antiproliferative activity and C60's photoinduced pro-oxidant activity. When cells were treated with 2:1 C60-Dox and irradiated at 405 nm the high cytotoxicity of photo-irradiated C60-Dox enabled a nanomolar concentration of Dox and C60 to efficiently kill cancer cells in vitro. The high pro-oxidant and pro-apoptotic efficiency decreased IC50 16, 9 and 7 × 103-fold, if compared with the action of Dox, non-irradiated nanocomplex, and C60's photodynamic effect, correspondingly. Hereafter, a strong synergy of therapy arising from the combination of C60-mediated Dox delivery and C60 photoexcitation was revealed. Our data indicate that a combination of chemo- and photodynamic therapies with C60-Dox nanoformulation provides a promising synergetic approach for cancer treatment.}, language = {en} } @article{LuxEdlingLuccietal.2019, author = {Lux, Helge and Edling, Matthias and Lucci, Massimiliano and Kitzmann, Julia and Villringer, Claus and Siemroth, Peter and De Matteis, Fabio and Schrader, Sigurd}, title = {The Role of Substrate Temperature and Magnetic Filtering for DLC by Cathodic Arc Evaporation}, series = {Coatings}, volume = {9}, journal = {Coatings}, number = {5}, issn = {2079-6412}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-12295}, pages = {345}, year = {2019}, abstract = {Diamond-like carbon (DLC) films were deposited using two different types of high current arc evaporation. The first process used a magnetic particle filter to remove droplets from the plasma. For the second process, the samples were put into a metallic cage which was placed directly above the plasma source. For both processes, we varied the substrate temperature from 21 to 350 °C in order to investigate the temperature effect. The samples were characterized using SEM, AFM, XPS, Raman Spectroscopy, Ellipsometry, Photometry, and Nano Indentation in order to compare both methods of deposition and provide a careful characterization of such DLC films. We found that the sp3 content and the hardness can be precisely adjusted by changing the substrate temperature. Furthermore, in the case of unfiltered deposition, the optical constants can be shifted in the direction of higher absorbance in order to produce black and hard carbon coatings.}, language = {en} } @article{SteglichVillringerDietzeletal.2019, author = {Steglich, Patrick and Villringer, Claus and Dietzel, Birgit and Mai, Christian and Schrader, Sigurd and Casalboni, Mauro and Mai, Andreas}, title = {On-Chip Dispersion Measurement of the Quadratic Electro-Optic Effect in Nonlinear Optical Polymers Using a Photonic Integrated Circuit Technology}, series = {IEEE Photonics Journal}, volume = {11}, journal = {IEEE Photonics Journal}, number = {3}, issn = {1943-0655}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-12307}, year = {2019}, abstract = {A novel method to determine the dispersion of the quadratic electro-optic effect in nonlinear optical materials by using a silicon-on-insulator microring resonator is presented. The microring consists of a silicon slot waveguide enabling large dc electric field strength at low applied voltages. The dispersion of third-order hyperpolarizability of a linear conjugated dye is approximated by using a two-level model for the off-resonant spectral region. As an example, the dispersion of the resonance wavelength of the resonator filled with a dye doped polymer was measured in dependence of the applied dc voltage. The polymer was poly (methylmethacrylate) doped with 5 wt\% disperse red 1 (DR1), and the measurements have been carried out at the telecommunication wavelength band around 1550 nm (optical C-band). The described measurements represent a new technique to determine the dispersion of the third-order susceptibility and molecular hyperpolarizability of the material filled into the slot of the ring-resonator.}, language = {en} } @article{MikayelyanGroddKsianzouetal.2019, author = {Mikayelyan, Eduard and Grodd, Linda and Ksianzou, Viachaslau and Wesner, Daniel and Rodygin, Alexander I. and Sch{\"o}nherr, Holger and Luponosov, Yuriy N. and Ponomarenko, Sergei A. and Ivanov, Dimitri A. and Pietsch, Ullrich and Grigorian, Souren}, title = {Phase Transitions and Formation of a Monolayer-Type Structure in Thin Oligothiophene Films: Exploration with a Combined In Situ X-ray Diffraction and Electrical Measurements}, series = {Nanoscale Research Letters}, volume = {14}, journal = {Nanoscale Research Letters}, issn = {1556-276X}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-12314}, year = {2019}, abstract = {A combination of in situ electrical and grazing-incidence X-ray diffraction (GIXD) is a powerful tool for studies of correlations between the microstructure and charge transport in thin organic films. The information provided by such experimental approach can help optimizing the performance of the films as active layers of organic electronic devices. In this work, such combination of techniques was used to investigate the phase transitions in vacuum-deposited thin films of a common organic semiconductor dihexyl-quarterthiophene (DH4T). A transition from the initial highly crystalline phase to a mesophase was detected upon heating, while only a partial backward transition was observed upon cooling to room temperature. In situ electrical conductivity measurements revealed the impact of both transitions on charge transport. This is partly accounted for by the fact that the initial crystalline phase is characterized by inclination of molecules in the plane perpendicular to the π-π stacking direction, whereas the mesophase is built of molecules tilted in the direction of π-π stacking. Importantly, in addition to the two phases of DH4T characteristic of the bulk, a third interfacial substrate-stabilized monolayer-type phase was observed. The existence of such interfacial structure can have important implications for the charge mobility, being especially favorable for lateral two-dimensional charge transport in the organic field-effect transistors geometry.}, language = {en} } @article{BondarenkoVillringerSteglich2019, author = {Bondarenko, Siegfried and Villringer, Claus and Steglich, Patrick}, title = {Comparative Study of Nano-Slot Silicon Waveguides Covered by Dye Doped and Undoped Polymer Cladding}, series = {Applied Sciences}, volume = {9}, journal = {Applied Sciences}, number = {1}, publisher = {MDPI}, issn = {2076-3417}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-10716}, year = {2019}, abstract = {Nonlinear optical dyes doped in optical polymer matrices are widely used for electro-optical devices. Linear optical properties change with dye concentration, which leads to a change in modal properties, especially in nano-structured integrated waveguides such as silicon slot-waveguides. Here, we investigate the influence of a nonlinear optical dye on the performance of a silicon-organic hybrid slot-waveguide. A simulation study of the modal and optical confinement properties is carried out and dependence of the structural parameters of the slot-waveguide and the organic cladding material is taken into account. As cladding material, a guest-host polymer system is employed comprising the nonlinear optical dye Disperse Red 1 (DR1) doped in a poly[methyl methacrylate] (PMMA) matrix. The refractive indices of doped and undoped PMMA were deduced from ellipsometric data. We present a guideline for an optimized slot-waveguide design for the fabrication in silicon-on-insulator technology giving rise to scalable, high-performance integrated electro-optical modulators.}, language = {en} } @article{SteglichHuelsemannDietzeletal.2019, author = {Steglich, Patrick and H{\"u}lsemann, Marcel and Dietzel, Birgit and Mai, Andreas}, title = {Optical Biosensors Based on Silicon-On-Insulator Ring Resonators: A Review}, series = {Molecules}, volume = {24}, journal = {Molecules}, number = {3}, issn = {1420-3049}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-10822}, year = {2019}, abstract = {Recent developments in optical biosensors based on integrated photonic devices are reviewed with a special emphasis on silicon-on-insulator ring resonators. The review is mainly devoted to the following aspects: (1) Principles of sensing mechanism, (2) sensor design, (3) biofunctionalization procedures for specific molecule detection and (4) system integration and measurement set-ups. The inherent challenges of implementing photonics-based biosensors to meet specific requirements of applications in medicine, food analysis, and environmental monitoring are discussed.}, language = {en} } @article{GrebinykPrylutskaGrebinyketal.2019, author = {Grebinyk, Anna and Prylutska, Svitlana and Grebinyk, Sergii and Prylutskyy, Yuriy and Ritter, Uwe and Matyshevska, Olga and Dandekar, Thomas and Frohme, Marcus}, title = {Complexation with C60 Fullerene Increases Doxorubicin Efficiency against Leukemic Cells In Vitro}, series = {Nanoscale Research Letters}, volume = {14}, journal = {Nanoscale Research Letters}, issn = {1556-276X}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-10966}, year = {2019}, abstract = {Conventional anticancer chemotherapy is limited because of severe side effects as well as a quickly evolving multidrug resistance of the tumor cells. To address this problem, we have explored a C60 fullerene-based nanosized system as a carrier for anticancer drugs for an optimized drug delivery to leukemic cells. Here, we studied the physicochemical properties and anticancer activity of C60 fullerene noncovalent complexes with the commonly used anticancer drug doxorubicin. C60-Doxorubicin complexes in a ratio 1:1 and 2:1 were characterized with UV/Vis spectrometry, dynamic light scattering, and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The obtained analytical data indicated that the 140-nm complexes were stable and could be used for biological applications. In leukemic cell lines (CCRF-CEM, Jurkat, THP1 and Molt-16), the nanocomplexes revealed ≤ 3.5 higher cytotoxic potential in comparison with the free drug in a range of nanomolar concentrations. Also, the intracellular drug's level evidenced C60 fullerene considerable nanocarrier function. The results of this study indicated that C60 fullerene-based delivery nanocomplexes had a potential value for optimization of doxorubicin efficiency against leukemic cells.}, language = {en} } @article{GrebinykPrylutskaGrebinyketal.2019, author = {Grebinyk, Anna and Prylutska, Svitlana and Grebinyk, Sergii and Prylutskyy, Yuriy and Ritter, Uwe and Matyshevska, Olga and Dandekar, Thomas and Frohme, Marcus}, title = {Complexation with C60 Fullerene Increases Doxorubicin Efficiency against Leukemic Cells In Vitro}, series = {Nanoscale Research Letters}, volume = {14}, journal = {Nanoscale Research Letters}, issn = {1556-276X}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-11415}, year = {2019}, abstract = {Conventional anticancer chemotherapy is limited because of severe side effects as well as a quickly evolving multidrug resistance of the tumor cells. To address this problem, we have explored a C60 fullerene-based nanosized system as a carrier for anticancer drugs for an optimized drug delivery to leukemic cells. Here, we studied the physicochemical properties and anticancer activity of C60 fullerene noncovalent complexes with the commonly used anticancer drug doxorubicin. C60-Doxorubicin complexes in a ratio 1:1 and 2:1 were characterized with UV/Vis spectrometry, dynamic light scattering, and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The obtained analytical data indicated that the 140-nm complexes were stable and could be used for biological applications. In leukemic cell lines (CCRF-CEM, Jurkat, THP1 and Molt-16), the nanocomplexes revealed ≤ 3.5 higher cytotoxic potential in comparison with the free drug in a range of nanomolar concentrations. Also, the intracellular drug's level evidenced C60 fullerene considerable nanocarrier function. The results of this study indicated that C60 fullerene-based delivery nanocomplexes had a potential value for optimization of doxorubicin efficiency against leukemic cells.}, language = {en} } @article{IdaChanGloekleretal.2019, author = {Ida, Jeunice and Chan, Soo Khim and Gl{\"o}kler, J{\"o}rn and Lim, Yee Ying and Choong, Yee Siew and Lim, Theam Soon}, title = {G-Quadruplexes as An Alternative Recognition Element in Disease-Related Target Sensing}, series = {Molecules}, volume = {24}, journal = {Molecules}, number = {6}, issn = {1420-3049}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-11438}, year = {2019}, abstract = {G-quadruplexes are made up of guanine-rich RNA and DNA sequences capable of forming noncanonical nucleic acid secondary structures. The base-specific sterical configuration of G-quadruplexes allows the stacked G-tetrads to bind certain planar molecules like hemin (iron (III)-protoporphyrin IX) to regulate enzymatic-like functions such as peroxidase-mimicking activity, hence the use of the term DNAzyme/RNAzyme. This ability has been widely touted as a suitable substitute to conventional enzymatic reporter systems in diagnostics. This review will provide a brief overview of the G-quadruplex architecture as well as the many forms of reporter systems ranging from absorbance to luminescence readouts in various platforms. Furthermore, some challenges and improvements that have been introduced to improve the application of G-quadruplex in diagnostics will be highlighted. As the field of diagnostics has evolved to apply different detection systems, the need for alternative reporter systems such as G-quadruplexes is also paramount.}, language = {en} } @article{LuxEdlingSiemrothetal.2018, author = {Lux, Helge and Edling, Matthias and Siemroth, Peter and Schrader, Sigurd}, title = {Fast and Cost-Effective Synthesis of High-Quality Graphene on Copper Foils Using High-Current Arc Evaporation}, series = {Materials}, volume = {11}, journal = {Materials}, number = {5}, issn = {1996-1944}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-10359}, pages = {1 -- 10}, year = {2018}, abstract = {In this paper, we present an innovative and ultra-fast process for the deposition of high-quality graphene on different metal foils and thin metal films. The graphene layer can be homogeneously deposited in only 30 s process time. Due to the weak adhesion to the substrate material, the monolayer graphene is easy to transfer using the established processes. For the production, we use magnetic filtered high-current arc evaporation (Φ-HCA) with a solid, graphitic carbon source. This ultra-fast growth process can pave the way towards a cost-effective graphene synthesis for the mass production e.g., in a roll-to-roll process, avoiding time consuming established processes.}, language = {en} }