TY - CHAP A1 - Mayer, Margot A1 - Arrizabalaga, Onetsine A1 - Schröder, Insa A1 - Ritter, Sylvia A1 - Thielemann, Christiane T1 - Human Embryonic Stem Cell Derived Neurospheres – 2D and 3D Cell Culture in one sample N2 - Various studies have shown that two dimensional (2D) neuronal cell cultures does not recapitulate structure and physiology of three-dimensional (3D) in vivo tissues. These findings are of paramount importance for drug screening, since the response to neurotoxicological substances may differ for 2D und 3D cell culture models. To address this topic, we present human embryonic stem cell (hESC) derived neurospheres (NS) coupled onto microelectrode array (MEA) chips as a model system that includes a 3D NS as well as an outgrowing 2D monolayer allowing direct comparison of functionality within one culture. Preliminary results revealed an enhanced functional reactions of 3D NS to GABA receptor antagonist bicuculline compared to the 2D domain. Thus we have the first evidence that hESC derived NS are a promising model system for neurotoxicity testing enabling a direct comparison between functionality of neurons grown in 2D or 3D. KW - MEA Chips KW - neurospheres KW - human embryonic stem cells KW - 3D KW - Bicuculline KW - Embryonale Stammzelle Y1 - 2018 UR - https://www.frontiersin.org/10.3389/conf.fncel.2018.38.00078/event_abstract ER - TY - CHAP A1 - Ciba, Manuel A1 - Thielemann, Christiane T1 - Synchrony changes on different time-scales during in vitro neuronal network development KW - Synchrony KW - Time-scales KW - spike-contrast KW - developing neuronal networks KW - spike train analysis KW - Neuronales Netz Y1 - 2018 UR - https://www.frontiersin.org/10.3389/conf.fncel.2018.38.00081/event_abstract ER - TY - CHAP A1 - Nick, Christoph A1 - Hock, Christina A1 - Emmerich, Florian A1 - Belle, Stefan A1 - Thielemann, Christiane A1 - Asmus, Tim A1 - Loose, Thomas A1 - Wienand, Karlheinz T1 - Ultrathin gold as sensor platform for biomolecules T2 - 2015 International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO), Changchun, China N2 - Due to the increasing number of diabetes patients worldwide there is an enormous need for accurate, fast and someday also continuous or even closed loop monitoring of blood glucose level. More than 50 years after Clark and Lyons proposed the first glucose enzyme electrodes this concept is still widely in use today. Most concepts use the enzyme glucose oxidase (GOx) that reacts with glucose. These reactions cause a current that is proportional to the amount of glucose present at the sensor. Thus, if the sample volume is known, the blood sugar level can be measured. Although these electrodes have been in use for so long they have the disadvantage of a limited shelf time. In this work we present an enzyme free approach for glucose detection applying ultrathin gold films. According to the basic Fuchs-Sondheimer-theory and other more sophisticated models the resistivity of ultrathin metal films is dominated by scattering effects at their surface. Chemical reactions at the metallic surface are expected to change the conductivity properties and thus these changes can be used to detect molecules. This can be done by creating a self-assembled monolayer at the gold surface. When molecules such as glucose bind to the end groups of this layer the electron scattering and thus the conductivity of the film is expected to change. Ultrathin gold films with a thickness of 6 nm show the largest relative change in resistivity and are thus the preferred film thickness for this application. These gold films show a significant change in resistance when model molecules sodium sulfide and dextran are present, whereas the resistance of a platinum reference electrode does not change significantly. KW - ultrathin gold KW - biosensor KW - glucose KW - enzyme free glucose sensor KW - Biosensor KW - Dünne Schicht KW - Gold Y1 - 2015 U6 - https://doi.org/10.1109/3M-NANO.2015.7425462 ER - TY - CHAP A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Patterning of PMMA by gold-nanoparticle initiated localized decomposition T2 - 2015 International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO), Changchun, China N2 - The need for manipulating matter at its smallest scale has been a hot topic in research for the last decades. As the final goal of arranging single atoms has been achieved, research focuses on two targets: firstly, improving the capabilities of existing technologies towards nanometer resolution and secondly, finding new methods for producing nanostructures in a fast and easy way. Here, we present a new maskless method for sub-micro-patterning of poly(methyl methacrylate) (PMMA) thin films. By applying atomic-force-microscope (AFM) assisted nano-xerography, electric charges were locally injected with an AFM-tip into PMMA. The resulting electrostatic patterns attracted charged gold-nanoparticles, which were selectively deposited onto the PMMA layers with lateral dimensions below 200 nm. In a second step, heat treatment at 275 °C initiated a selective decomposition of the PMMA layer, only observed in PMMA-areas covered with nanoparticles, whereas uncovered areas were not modified by the heat treatment. Analyzing the grooves with the AFM, we found that lines with a width in the sub-micrometer range to several micrometers have successfully been realized. We propose this new and promising method to manufacture nano-grooves used as masking for lift-off processes, for functionalization of underlying areas, or for micro-contact-printing. KW - Nanoparticles KW - Gold KW - Thermal stability KW - Heating KW - Electrostatics KW - Polymethylmethacrylate KW - Dünnschichttechnik Y1 - 2015 U6 - https://doi.org/10.1109/3M-NANO.2015.7425480 ER - TY - CHAP A1 - Nick, Christoph A1 - Thielemann, Christiane A1 - Joshi, Ravi A1 - Schneider, Jörg T1 - Niedrigtemperatur-Transfer von vertikal ausgerichteten Kohlenstoff Nanoröhren auf Mikrostrukturen T2 - Mikro-Nano-Integration - 3. GMM-Workshop, Stuttgart, Deutschland, 2011 N2 - Vertikal angeordnete Kohlenstoff Nanoröhren (engl. vertically aligned carbon nanotubes; VA-CNT) können seit einigen Jahren mit hoher Reproduzierbarkeit durch CVD-Verfahren bei 600 °C - 800 °C auf Katalysatorschichten aus Aluminium und Eisen hergestellt werden. Sie zeigen sehr gute Eigenschaften im Bereich der Feldemission, aber auch in sub-µm Vias. Allerdings sind die relativ hohen Temperaturen oft nicht prozesskompatibel und müssen vermieden werden um keine Degradation darunterliegender Strukturen in Kauf zu nehmen. Da die Reduzierung der CVD-Temperaturen beim Wachstum der VA-CNTs unter 600 °C zu hohen Defektraten führt, schlagen wir ein neues Verfahren zum Transfer der VA-CNTs bei niedrigen Temperaturen vor. In einer Kombination aus Flip-Chip- und Stempel-Technik werden hoch geordnete, mikrostrukturierte VA-CNTs auf temperaturempfindliche Substrate aus Kalk-Natron-Glas, Gold oder Kupfer bei Temperaturen von 100 °C transferiert. Die vertikale Struktur der Nanoröhren bleibt dabei erhalten. Eine leitende Verbindung kann durch ein leitfähiges, bio-kompatibles Polymer gewährleistet werden, was eine Erweiterung des Einsatzbereichs auf Life-Science Applikationen erlauben würde. KW - Kohlenstoff-Nanoröhre Y1 - 2011 ER - TY - CHAP A1 - Yilmazoglu, Oktay A1 - Al-Daffaie, Shihab A1 - Hartnagel, Hans A1 - Joshi, Ravi A1 - Yadav, Sandeep A1 - Schneider, Jörg A1 - Nick, Christoph A1 - Thielemann, Christiane T1 - CNT photocathodes based on GaAs high-frequency photoswitches T2 - 25th International Vacuum Nanoelectronics Conference, 9 - 13 July 2012, Jeju, South Korea N2 - A high-frequency photocathode based on carbon nanotube (CNT) blocks on semiisolating GaAs or low-temperature grown GaAs was fabricated and used for electron emission in a diode configuration. The CNT blocks can achieve high currents and current densities of I=0.5 mA and J=28 mA/cm 2 at E=2.1 V/μm, respectively. The photomodulation was achieved with a GaAs photoswitch electrically connected to the bottom of the CNT block emitter. This photocathode can find applications in high frequency tubes and optically driven X-ray sources. KW - Kohlenstoff-Nanoröhre Y1 - 2012 U6 - https://doi.org/10.1109/IVNC.2012.6316840 ER - TY - CHAP A1 - Mayer, Margot A1 - Arrizabalaga, Onetsine A1 - Ritter, Sylvia A1 - Thielemann, Christiane T1 - Human Embryonic Stem Cell Derived Neurospheres - A Novel Three Dimensional Model For Neurotoxicological Studies T2 - Frontiers N2 - At present, most neurotoxicological studies in the field of microelectrode array (MEA) technology are based on in vivo or in vitro animal models, particularly in mice or rats. These models contributed much to our knowledge about molecular and cellular mechanisms of neurotoxins affecting the central nervous system. Yet, animal models are not necessarily capable to forecasting the effectiveness of treatment in clinical trials. Therefore the development and characterization of suitable neuronal cell models derived from human cells is emerging in the field of toxicity testing. In this study, we present neurospheres (NS) as a new three dimensional (3D) neuronal cell model based on human embryonic stem cells (hESC), coupled onto microelectrode arrays (MEA). This cell-based assay serves as platform to investigate effects of neuroactive substances on network communication. In order to characterize the neurospheres’ reaction, the well-known GABA receptor antagonist bicuculline and the sodium channel blocker carbamazepine are applied. Preliminary results reveal anticipated and physiologically reasonable alterations in network activity. Thus, we have the first evidence that hESC derived NS are a promising 3D cell model for neurotoxicity testing. In further studies, this model will be used to investigate effects of ionizing radiation on network signaling. KW - human embryonic stem cells KW - neurospheres KW - MEA chips KW - 3D KW - Mikroelektrode KW - Array KW - Embryonale Stammzelle Y1 - 2016 U6 - https://doi.org/10.3389/conf.fnins.2016.93.00081 VL - 2016 IS - MEA Meeting 2016 ER - TY - CHAP A1 - Arnheiter, Frank A1 - Asmus, Tim A1 - Loose, Thomas A1 - Wienand, Karlheinz A1 - Thielemann, Christiane T1 - Metal-nanosensor for the detection of biomolecules T2 - Mikro-Nano Integration (GMM-Fachbericht 60), KW - Mikrosystemtechnik KW - Sensor Y1 - 2014 SN - 978-3-8007-3155-8 ER - TY - CHAP A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Observation of Thermal Discharge in Nanopatterned Electrets by Kelvin-Probe-Microscopy T2 - 14th International Symposium on Elecrets, 2011, Montpellier, France KW - Elektret Y1 - 2014 SN - 978-1-4577-1023-0 SN - 2153-3253 SP - 149 EP - 150 ER - TY - CHAP A1 - Frieß, Johannes A1 - Ritter, Sylvia A1 - Daus, Andreas A1 - Layer, Paul A1 - Thielemann, Christiane A1 - Heselich, Anja T1 - Electrophysiologic and Molecular Characteristics of Cardiomyocytes after Heavy Ion Irradiation in the frame of the ESA IBER-10 Program T2 - Heavy Ion in Therapie and Space Radiation Symposium (HITSRS2013), 2013, Chiba, Japan KW - Herzmuskelzelle KW - Ionenbestrahlung KW - Schweres Ion Y1 - 2013 ER - TY - CHAP A1 - Nick, Christoph A1 - Bestel, Robert A1 - Steger, Frederik A1 - Thielemann, Christiane T1 - Spike Detection, Sorting and Propagation of Cell Signals Recorded with Extracellular Microelectrodes, Engineering in Medicine and Biology Society T2 - IEMBS’13, 35th Annual International Conference of the IEEE KW - Pulsverarbeitendes neuronales Netz KW - Zellwachstum Y1 - 2013 ER - TY - CHAP A1 - Daus, Andreas A1 - Oster, Stefan A1 - Erbes, Christian A1 - Goldhammer, Michael A1 - Bochtler, Ulrich A1 - Thielemann, Christiane T1 - Electromagnetic exposure of neuronal networks on microelectrode arrays T2 - U.R.S.I. Landesausschuss in der Bundesrepublik Deutschland e.V., Kleinheubacher Tagung, Miltenberg, Abstracts KW - Neuronales Netz KW - Mikroelektrode KW - Array Y1 - 2013 SP - 29 EP - 30 ER - TY - CHAP A1 - Oster, Stefan A1 - Daus, Andreas A1 - Goldhammer, Michael A1 - Bochtler, Ulrich A1 - Thielemann, Christiane T1 - A Flexible RF Exposure Setup for Long-term Electrophysiological Investigations on Biological Samples in Vitro T2 - Progress In Electromagnetics Research Symposium Abstracts, Stockholm, Schweden KW - Neuronales Netz KW - Array KW - Mikroelektrode Y1 - 2013 ER - TY - CHAP A1 - Obmann, Julia A1 - Polt, Christopher A1 - Loose, Thomas A1 - Asmus, Tim A1 - Wienand, Karlheinz A1 - Thielemann, Christiane T1 - Novel Resistive Bioaffinity Sensor based on Ultra-Thin Gold Films T2 - 3rd International Conference on Bio-Sensing Technology 2013, Sitges, Spain KW - Biosensor KW - Dünne Schicht Y1 - 2013 ER - TY - CHAP A1 - Goldhammer, Michael A1 - Daus, Andreas A1 - Thielemann, Christiane A1 - Bochtler, Ulrich T1 - Flexible measurement setup for electromagnetic exposition of biological samples T2 - BioEM 2009, Davos, Switzerland KW - Elektromagnetische Strahlung KW - Messung Y1 - 2014 ER - TY - CHAP A1 - Daus, Andreas A1 - Goldhammer, Michael A1 - Bochtler, Ulrich A1 - Thielemann, Christiane T1 - Electromagnetic exposition of neuronal networks in vitro T2 - Radiofrequency fields and health KW - Neuronales Netz Y1 - 2014 ER - TY - CHAP A1 - Daus, Andreas A1 - Hasenkopf, Matthias A1 - Thielemann, Christiane T1 - Novel 3D cell culture systems for electromagnetic exposure studies T2 - BioEM 2009, Davos, Switzerland KW - Zellkultur Y1 - 2009 ER - TY - CHAP A1 - Steger, Frederik A1 - Frieß, Johannes A1 - Daus, Andreas A1 - Ritter, Sylvia A1 - Thielemann, Christiane T1 - Analysis of electrophysiological characteristics of cardiomyocytes following radiation exposure T2 - 8th International Meeting on Substrate-Integrated Microelectrode Arrays KW - Herzmuskelzelle KW - Strahlenbelastung Y1 - 2014 U6 - https://doi.org/10.13140/RG.2.1.4153.0400 SN - 2194-5519 SP - 153 ER - TY - CHAP A1 - Nick, Christoph A1 - Joshi, Ravi A1 - Schlaak, Helmut A1 - Schneider, Jörg A1 - Thielemann, Christiane T1 - Multi electrode array with carbon nanotube electrodes for the extra-cellular detection of action potentials T2 - MikroSystemTechnik Kongress 2011, Darmstadt KW - Mehrfachelektrode KW - Elektrodenarray Y1 - 2014 ER - TY - CHAP A1 - Daus, Andreas A1 - Goldhammer, Michael A1 - Thielemann, Christiane T1 - Using three-dimensional cell culture systems on Microelectrode arrays for biosensing applications T2 - 7th international Meeting on subtrate-intergrated microelectrode arrays, Reutlingen KW - Array KW - Mikroelektrode KW - Biosensor Y1 - 2014 SN - 978-3-938345-08-5 SP - 314 EP - 315 ER - TY - CHAP A1 - Thielemann, Christiane A1 - Ritter, Sylvia A1 - Layer, Paul A1 - Frieß, Johannes A1 - Daus, Andreas A1 - Steger, Frederik A1 - Heselich, Anja T1 - Cellular effects of space radiation with relevance to cardiovascular diseases T2 - Life in Space for Life on Earth KW - Kardiovaskuläre Krankheit KW - Ionisierende Strahlung Y1 - 2014 N1 - IBER-10 SP - 560 ER -