TY - JOUR A1 - Peters, R. A1 - Elbers, I. A1 - Undas, A. A1 - Sijtsma, E. A1 - Briffa, S. A1 - Carnell-Morris, P. A1 - Siupa, A. A1 - Yoon, T.-H. A1 - Burr, L. A1 - Schmid, D. A1 - Tentschert, J. A1 - Hachenberger, Y. A1 - Jungnickel, H. A1 - Luch, A. A1 - Meier, F. A1 - Kocic, J. A1 - Kim, J. A1 - Park, B. C. A1 - Hardy, B. A1 - Johnston, C. A1 - Jurkschat, K. A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Lynch, I. A1 - Valsami-Jones, E. T1 - Benchmarking the ACEnano toolbox for characterisation of nanoparticle size and concentration by interlaboratory comparisons N2 - ACEnano is an EU-funded project which aims at developing, optimising and validating methods for the detection and characterisation of nanomaterials (NMs) in increasingly complex matrices to improve confidence in the results and support their use in regulation. Within this project, several interlaboratory comparisons (ILCs) for the determination of particle size and concentration have been organised to benchmark existing analytical methods. In this paper the results of a number of these ILCs for the characterisation of NMs are presented and discussed. The results of the analyses of pristine well-defined particles such as 60 nm Au NMs in a simple aqueous suspension showed that laboratories are well capable of determining the sizes of these particles. The analysis of particles in complex matrices or formulations such as consumer products resulted in larger variations in particle sizes within technologies and clear differences in capability between techniques. Sunscreen lotion sample analysis by laboratories using spICP-MS and TEM/SEM identified and confirmed the TiO2 particles as being nanoscale and compliant with the EU definition of an NM for regulatory purposes. In a toothpaste sample orthogonal results by PTA, spICP-MS and TEM/SEM agreed and stated the TiO2 particles as not fitting the EU definition of an NM. In general, from the results of these ILCs we conclude that laboratories are well capable of determining particle sizes of NM, even in fairly complex formulations. KW - Nanomaterials KW - Benchmarking KW - Inter-laboratory comparison KW - ACEnano KW - Characterisation KW - Size KW - Concentration PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531852 DO - https://doi.org/10.3390/molecules26175315 SN - 1420-3049 VL - 26 IS - 17 SP - 1 EP - 23 PB - MDPI CY - Basel AN - OPUS4-53185 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Peters, R. A1 - Elbers, I. A1 - Undas, A. A1 - Sijtsma, E. A1 - Briffa, S. A1 - Carnell-Morris, P. A1 - Siupa, A. A1 - Yoon, T.-H. A1 - Burr, L. A1 - Schmid, D. A1 - Tentschert, J. A1 - Hachenberger, Y. A1 - Jungnickel, H. A1 - Luch, A. A1 - Meier, F. A1 - Kocic, J. A1 - Kim, J. A1 - Park, B. C. A1 - Hardy, B. A1 - Johnston, C. A1 - Jurkschat, K. A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Lynch, I. A1 - Valsami-Jones, E. T1 - Correction: Peters et al. Benchmarking the ACEnano Toolbox for Characterisation of Nanoparticle Size and Concentration by Interlaboratory Comparisons. Molecules 2021, 26, 5315 N2 - This is a corrigendum to the original article "Benchmarking the ACEnano toolbox for characterisation of nanoparticle size and concentration by interlaboratory comparisons" that was published in the journal "Molecules", vol. 26 (2021), no. 17, article 5315. PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554381 DO - https://doi.org/10.3390/molecules27154849 VL - 27 IS - 4849 SP - 1 EP - 3 PB - MDPI CY - Basel AN - OPUS4-55438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, X.-d. A1 - Meier, R.J. A1 - Schäferling, Michael A1 - Bange, S. A1 - Lupton, J.M. A1 - Sperber, M. A1 - Wegener, J. A1 - Ondrus, V. A1 - Beifuss, U. A1 - Henne, U. A1 - Klein, C. A1 - Wolfbeis, Otto S. T1 - Two-photon excitation temperature nanosensors based on a conjugated fluorescent polymer doped with an Europium probe N2 - A strongly fluorescent organic semiconducting polymer doped with a highly temperature dependent fluorescent europium(III) complex is converted into a nanosized material that is capable of optically sensing temperature (T) in the range from 0 to 50 °C via two-photon excitation at 720 nm. The nanosensors are prepared from a blue-fluorescent polyfluorene that acts as both a lightharvesting antenna (to capture two-photon energy) and an energy donor in a fluorescence resonance energy transfer (FRET) system. The photonic energy absorbed by the polymer is transferred to the T-sensitive red-luminescent europium complex contained in the nanoparticles. The close spatial proximity of the donor and the acceptor warrants efficient FRET. A poly(ethylene glycol)- co-poly(propylene oxide) block copolymer is also added to render the particles biocompatible. It is shown that T can be calculated from a) the intensity of the luminescence of the europium complex, b) the ratio of the intensities of the red and blue luminescence, or c) the T-dependent luminescence lifetime of the Eu(III) complex. KW - Optical sensor KW - Temperature sensor KW - Nanosensor KW - FRET system PY - 2016 UR - http://onlinelibrary.wiley.com/doi/10.1002/adom.201600601/abstract DO - https://doi.org/10.1002/adom.201600601 SN - 2195-1071 VL - 4 IS - 11 SP - 1854 EP - 1859 PB - Wiley-VCH CY - Weinheim AN - OPUS4-38737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Burkert, Andreas A1 - Ebell, Gino A1 - Eichler, T. A1 - Hariri, K. A1 - Harnisch, J. A1 - Keßler, S. A1 - Mayer, T.F. A1 - Meier, J. A1 - Mietz, Jürgen A1 - Reichling, K. A1 - Sodeikat, C. T1 - Merkblatt für Elektrochemische Potentialmessungen zur Detektion von Bewehrungsstahlkorrosion KW - Stahlbeton KW - Korrosion KW - Bewehrung KW - Potentialmessung KW - Zerstörungsfreie Prüfung PY - 2014 SN - 978-3-940283-10-8 VL - B 03 SP - 1 EP - 19 CY - Berlin AN - OPUS4-31077 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Burkert, Andreas A1 - Ebell, Gino A1 - Eichler, T. A1 - Hariri, K. A1 - Harnisch, J. A1 - Keßler, S. A1 - Mayer, T.F. A1 - Meier, J. A1 - Mietz, Jürgen A1 - Reichling, K. A1 - Sodeikat, C. T1 - Merkblatt B 03 - Merkblatt für Elektrochemische Potentialmessungen zur Detektion von Bewehrungsstahlkorrosion N2 - Dieses Merkblatt beschreibt die Anwendung elektrochemischer Potentialmessungen (häufig auch als Potentialfeldmessung bezeichnet) zur Detektion von Bewehrungsstahlkorrosion an Stahlbetonbauwerken. Mit Hilfe dieses Verfahrens können Bereiche korrodierender Bewehrung zerstörungsfrei lokalisiert werden. In der Regel kommt diese Messmethode bei der Detektion chloridinduzierter Korrosion zum Einsatz. In Abgrenzung hierzu sollte die Abschätzung der Gefahr einer karbonatisierungsinduzierten Korrosion durch Bestimmung der Karbonatisierungstiefe und der Betondeckung erfolgen. KW - Korrosion KW - Betonstahl KW - Chloridinduzierte Korrosion KW - Potentialfeldmessung PY - 2014 SN - 978-3-940283-10-8 SP - 1 EP - 19 CY - Berlin ET - Überarbeitete Ausgabe April 2014 AN - OPUS4-31518 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haase, A. A1 - Arlinghaus, H. F. A1 - Tentschert, J. A1 - Jungnickel, H. A1 - Graf, P. A1 - Mantion, Alexandre A1 - Draude, F. A1 - Galla, S. A1 - Plendl, J. A1 - Goetz, M.E. A1 - Masic, A. A1 - Meier, W. A1 - Thünemann, Andreas A1 - Taubert, A. A1 - Luch, A. T1 - Application of laser postionization secondary neutral mass spectrometry / time-of-flight secondary ion mass spectrometry in nanotoxicology: Visualization of nanosilver in human macrophages and cellular responses N2 - Silver nanoparticles (SNP) are the subject of worldwide commercialization because of their antimicrobial effects. Yet only little data on their mode of action exist. Further, only few techniques allow for visualization and quantification of unlabeled nanoparticles inside cells. To study SNP of different sizes and coatings within human macrophages, we introduce a novel laser postionization secondary neutral mass spectrometry (Laser-SNMS) approach and prove this method superior to the widely applied confocal Raman and transmission electron microscopy. With time-of-flight secondary ion mass spectrometry (TOF-SIMS) we further demonstrate characteristic fingerprints in the lipid pattern of the cellular membrane indicative of oxidative stress and membrane fluidity changes. Increases of protein carbonyl and heme oxygenase-1 levels in treated cells confirm the presence of oxidative stress biochemically. Intriguingly, affected phagocytosis reveals as highly sensitive end point of SNP-mediated adversity in macrophages. The cellular responses monitored are hierarchically linked, but follow individual kinetics and are partially reversible. KW - Nanosilver KW - Laser-SNMS KW - TOF-SIMS KW - Confocal Raman microscopy KW - Oxidative stress KW - Protein carbonyls PY - 2011 DO - https://doi.org/10.1021/nn200163w SN - 1936-0851 VL - 5 IS - 4 SP - 3059 EP - 3068 PB - ACS Publ. CY - Washington, DC, USA AN - OPUS4-23656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Burkert, Andreas A1 - Ebell, Gino A1 - Eichler, T. A1 - Hariri, K. A1 - Harnisch, J. A1 - Keßler, S. A1 - Mayer, T. A1 - Meier, J. A1 - Mietz, Jürgen A1 - Reichling, K. A1 - Sodeikat, C. T1 - Electrochemical half-cell potential measurements for the detection of reinforcement corrosion N2 - This specification describes the application of electrochemical half‐cell potential measurements (frequently also called potential mapping) for the detection of reinforcement corrosion in reinforced concrete structures. Areas of corroding reinforcement steel can be located in a nondestructive manner by means of this procedure. Half‐cell potential measurements are used in order to detect chloride‐induced corrosion. However, it is not recommended in order to assess the risk of carbonation‐induced corrosion. For this purpose the determination of the carbonation depth and the concrete cover appear to be more appropriate. The content of this specification exclusively refers to the application of mobile, local variable reference electrodes, which are only placed on the concrete surface while measuring. The technique distinguishes itself thereby from the range of corrosion monitoring systems with stationary installed reference electrodes and sensor systems, respectively, whereby it is possible to continuously track measurements within the area of the installed electrodes. However, these methods are not dealt with in this specification. KW - Monitoring KW - Corrosion KW - Reinforcement PY - 2014 SN - 978-3-940283-72-6 SP - B 03, 1 EP - 19 PB - DGZfP CY - Berlin AN - OPUS4-40419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wildgruber, M. A1 - Lueg, C. A1 - Borgmeyer, S. A1 - Karimov, I. A1 - Braun, Ulrike A1 - Kiechle, M. A1 - Meier, R. A1 - Koehler, M. A1 - Ettl, J. A1 - Berger, H. T1 - Polyurethane versus silicone catheters for central venous port devices implanted at the forearm N2 - Purpose: We aimed to analyse short and long-term complications of polyurethane (PU) versus silicone catheters used in totally implantable venous-access ports (TIVAPs) implanted at the forearm. Methods: Retrospective analysis of 698 consecutively implanted TIVAPs was performed. Primary end-points were defined as rates of major complications associated with either type of central venous port catheter. Technical success rate, device service interval as well as minor complications not requiring port explantation were defined as secondary end-points. Results: A total of 698 port devices were implanted in 681 patients, 396 equipped with a PU catheter, 302 with a silicone catheter. The technical success rate was 99.9% with no major periprocedural complications. During follow-up a total of 211 complications in 146 patients were observed (1.0/1000 catheter days), 183 occurred associated with PU catheters (1.8/100 catheter days), 28 (0.3/1000 catheter days) with silicone catheters (log rank test p < 0.0001). Catheter-related bloodstream infections as well as thrombotic complications occurred significantly more frequently with PU catheters, while silicone catheters exhibited a trend towards a higher rate of mechanical failure such as disconnection or catheter rupture. Major complications requiring explantation of the device occurred more frequently with PU-based catheters (10.6%) compared to silicone catheter carrying ports (4.6%, log rank test p < 0.001). KW - Chemotherapy KW - Central venous access port KW - Complication KW - Thrombosis KW - Infection PY - 2016 DO - https://doi.org/10.1016/j.ejca.2016.02.011 SN - 0959-8049 VL - 59 SP - 113 EP - 124 PB - Elsevier Ltd. CY - Oxford, UK AN - OPUS4-36288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meier, R.J. A1 - Simbürger, J.M.B. A1 - Soukka, T. A1 - Schäferling, Michael T1 - A FRET based pH probe with broad working range applicable to referenced ratiometric dual wavelength and luminescence lifetime read out N2 - A luminescent probe for determination of pH was designed based on a Förster resonance energy transfer (FRET) system, combining a europium chelate as the donor and carboxynaphtho-fluorescein as a pH sensitive acceptor. The FRET system enables referenced pH detection in an exceptional broad dynamic range from pH 3 to 9. PY - 2015 DO - https://doi.org/10.1039/c5cc00144g SN - 0022-4936 SN - 0009-241x SN - 1359-7345 SN - 1364-548x VL - 51 IS - 28 SP - 6145 EP - 6148 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-33858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schepers, Winfried A1 - Brinkgreve, Ronald B. J. A1 - Holtzendorff, Kira A1 - Wegener, Dirk A1 - Appel, Silke A1 - Efthymiou, Georgia A1 - Krajewski, Wolfgang A1 - Machaček, Jan A1 - Meier, Thomas A1 - Nseir, Bashar A1 - Rangelow, Peter A1 - Schmitt, Jürgen A1 - Staubach, Patrick A1 - Vrettos, Christos T1 - Numerische Ermittlung von Baugrundschwingungen bei dynamisch belasteten Fundamenten: Empfehlungen zur Modellierung T1 - Numerical analysis of soil vibrations due to vibrating foundations: Guidance for model design N2 - AbstractIn der Praxis tätige geotechnisch Planende kommen in zunehmendem Maße mit dynamischen Fragestellungen in Berührung. Hersteller von geotechnischer Berechnungssoftware haben entsprechend ihre ursprünglich für statische Aufgabenstellungen konzipierten Produkte um die Möglichkeit zur Lösung von Wellenausbreitungsproblemen im Baugrund erweitert. Den Anwendern fehlt aber häufig die notwendige Erfahrung zur Durchführung dieser Art von numerischen Berechnungen. Die Arbeitskreise 1.4 „Baugrunddynamik“ und 1.6 „Numerik in der Geotechnik“ der Deutschen Gesellschaft für Geotechnik (DGGT) haben diese Entwicklung aufgegriffen und einen gemeinsamen Unterarbeitskreis „Numerik in der Baugrunddynamik“ gegründet. Der vorliegende Beitrag stellt die aktuellen Ergebnisse der Arbeit des Unterarbeitskreises vor und fasst die gewonnenen Erkenntnisse in Form von Empfehlungen zusammen. N2 - Geotechnical engineers are increasingly concerned with wave propagation problems. Manufacturers of geotechnical analysis software added features for soil dynamic analyses to their products initially devised for static geotechnical analyses. Though, users often lack the experience for conducting such advanced numerical analyses. Working groups 1.4 "Soil dynamics" and 1.6 "Numerical analyses in geotechnical engineering" of DGGT German Society for Geotechnical Engineering established a joint subgroup "Numerical analyses in soil dynamics" to address this shortcoming. The present paper presents the work of the subgroup so far and provides some guidance on conducting numerical analyses in soil dynamics. KW - Wellenausbreitung KW - Numerische Methoden KW - Empfehlungen KW - Modellgröße KW - Zeitschrittweite PY - 2024 DO - https://doi.org/10.1002/gete.202400016 SN - 0172-6145 VL - 47 IS - 4 SP - 254 EP - 268 PB - Ernst CY - Berlin AN - OPUS4-62078 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Duc, L. A1 - Noll, Matthias A1 - Meier, B.E. A1 - Bürgmann, H. A1 - Zeyer, J. T1 - High Diversity of Diazotrophs in the Forefield of a Receding Alpine Glacier N2 - Forefields of receding glaciers are unique and sensitive environments representing natural chronosequences. In such habitats, microbial nitrogen fixation is of particular interest since the low concentration of bioavailable nitrogen is one of the key limitations for growth of plants and soil microorganisms. Asymbiotic nitrogen fixation in the Damma glacier (Swiss Central Alps) forefield soils was assessed using the acetylene reduction assay. Free-living diazotrophic diversity and population structure were resolved by assembling four NifH sequence libraries for bulk and rhizosphere soils at two soil age classes (8- and 70-year ice-free forefield). A total of 318 NifH sequences were analyzed and grouped into 45 unique phylotypes. Phylogenetic analyses revealed a higher diversity as well as a broader distribution of NifH sequences among phylogenetic clusters than formerly observed in other environments. This illustrates the importance of free-living diazotrophs and their potential contribution to the global nitrogen input in this nutrient-poor environment. NifH diversity in bulk soils was higher than in rhizosphere soils. Moreover, the four libraries displayed low similarity values. This indicated that both soil age and the presence of pioneer plants influence diversification and population structure of free-living diazotrophs. KW - Diazotrophs KW - Glacier forefield KW - Chronosequence KW - Pioneer plant KW - NifH diversity PY - 2009 DO - https://doi.org/10.1007/s00248-008-9408-5 SN - 0095-3628 SN - 1432-184X VL - 57 IS - 1 SP - 179 EP - 190 PB - Springer CY - New York, NY ; Heidelberg ; Berlin AN - OPUS4-18646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haase, A. A1 - Rott, S. A1 - Mantion, Alexandre A1 - Graf, P. A1 - Plendl, J. A1 - Thünemann, Andreas A1 - Meier, W.P. A1 - Taubert, A. A1 - Luch, A. A1 - Reiser, G T1 - Effects of silver nanoparticles on primary mixed neural cell cultures: uptake, oxidative stress and acute calcium responses N2 - In the body, nanoparticles can be systemically distributed and then may affect secondary target organs, such as the central nervous system (CNS). Putative adverse effects on the CNS are rarely investigated to date. Here, we used a mixed primary cell model consisting mainly of neurons and astrocytes and a minor proportion of oligodendrocytes to analyze the effects of well-characterized 20 and 40 nm silver nanoparticles (SNP). Similar gold nanoparticles served as control and proved inert for all endpoints tested. SNP induced a strong size-dependent cytotoxicity. Additionally, in the low concentration range (up to 10 µg/ml of SNP), the further differentiated cultures were more sensitive to SNP treatment. For detailed studies, we used low/medium dose concentrations (up to 20 µg/ml) and found strong oxidative stress responses. Reactive oxygen species (ROS) were detected along with the formation of protein carbonyls and the induction of heme oxygenase-1. We observed an acute calcium response, which clearly preceded oxidative stress responses. ROS formation was reduced by antioxidants, whereas the calcium response could not be alleviated by antioxidants. Finally, we looked into the responses of neurons and astrocytes separately. Astrocytes were much more vulnerable to SNP treatment compared with neurons. Consistently, SNP were mainly taken up by astrocytes and not by neurons. Immunofluorescence studies of mixed cell cultures indicated stronger effects on astrocyte morphology. Altogether, we can demonstrate strong effects of SNP associated with calcium dysregulation and ROS formation in primary neural cells, which were detectable already at moderate dosages. KW - Silver nanoparticles KW - Neurons KW - Oxidative stress KW - Protein carbonyls KW - Calcium KW - Reference material KW - Nanoparticle KW - Small-angle X-ray scattering KW - SAXS PY - 2012 DO - https://doi.org/10.1093/toxsci/kfs003 SN - 1096-6080 SN - 1096-0929 VL - 126 IS - 2 SP - 457 EP - 468 PB - Oxford University Press CY - Oxford AN - OPUS4-25633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haase, A. A1 - Mantion, Alexandre A1 - Graf, P. A1 - Plendl, J. A1 - Thünemann, Andreas A1 - Meier, W. A1 - Taubert, A. A1 - Luch, A. T1 - A novel type of silver nanoparticles and their advantages in toxicity testing in cell culture systems N2 - Silver nanoparticles (SNPs) are among the most commercialized nanoparticles worldwide. Often SNP are used because of their antibacterial properties. Besides that they possess unique optic and catalytic features, making them highly interesting for the creation of novel and advanced functional materials. Despite its widespread use only little data exist in terms of possible adverse effects of SNP on human health. Conventional synthesis routes usually yield products of varying quality and property. It thus may become puzzling to compare biological data from different studies due to the great variety in sizes, coatings or shapes of the particles applied. Here, we applied a novel synthesis approach to obtain SNP of well-defined colloidal and structural properties. Being stabilized by a covalently linked small peptide, these particles are nicely homogenous, with narrow size distribution, and form monodisperse suspensions in aqueous solutions. We applied these peptide-coated SNP in two different sizes of 20 or 40 nm (Ag20Pep and Ag40Pep) and analyzed responses of THP-1-derived human macrophages while being exposed against these particles. Gold nanoparticles of similar size and coating (Au20Pep) were used for comparison. The cytotoxicity of particles was assessed by WST-1 and LDH assays, and the uptake into the cells was confirmed via transmission electron microscopy. In summary, our data demonstrate that this novel type of SNP is well suited to serve as model system for nanoparticles to be tested in toxicological studies in vitro. KW - Silver nanoparticles KW - Peptide coating KW - Nanotoxicity PY - 2012 DO - https://doi.org/10.1007/s00204-012-0836-0 SN - 0340-5761 SN - 1432-0738 VL - 86 IS - 7 SP - 1089 EP - 1098 PB - Springer CY - Berlin ; Heidelberg [u.a.] AN - OPUS4-26269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braun, Ulrike A1 - Lorenz, Edelgard A1 - Weimann, Christiane A1 - Sturm, Heinz A1 - Karimov, I. A1 - Ettl, J. A1 - Meier, R. A1 - Wohlgemuth, W. A. A1 - Berger, H. A1 - Wildgruber, M. T1 - Mechanic and surface properties of central-venous port catheters after removal: A comparison of polyurethane and Silicon rubber materials N2 - Central venous port devices made of two different polymeric materials, thermoplastic polyurethane (TPU)and silicone rubber (SiR), were compared due their material properties. Both naïve catheters as well as catheters after removal from patients were investigated. In lab experiments the influence of various chemo-therapeutic solutions on material properties was investigated, where as the samples after removal were compared according to the implanted time inpatient. The macroscopic,mechanical performance was assessed with dynamic, specially adapted tests for elasticity. The degradation status of the materials was determined with common tools of polymer characterisation, such as infrared spectroscopy, molecular weight measurements and various methods of thermal analysis. The surface morphology was an alysed using scanning electron microscopy. A correlation between material properties and clinical performance was proposed. The surface morphology and chemical composition of the polyurethane catheter materials can potentially result in increased susceptibility of the catheter to bloodstream infections and thrombotic complications. The higher mechanic failure,especially with increasing implantation time of the silicone catheters is related to the lower mechanical performance compared to the polyurethane material as well as loss of barium sulphate filler particles near the surface of the catheter. This results in preformed microscopic notches, which act as predetermined sites of fracture. KW - Thermoplastic polyurethane (TPU) KW - Silicone rubber (SiR) KW - Catheters KW - Central venous access port KW - Complication KW - Structure propertyrelationship KW - Mechanical testing PY - 2016 DO - https://doi.org/10.1016/j.jmbbm.2016.08.002 SN - 1751-6161 SN - 1878-0180 VL - 64 SP - 281 EP - 291 PB - Elsevier Ltd. AN - OPUS4-37178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Casse, O. A1 - Shkilnyy, A. A1 - Linders, J. A1 - Mayer, C. A1 - Häussinger, D. A1 - Völkel, A. A1 - Thünemann, Andreas A1 - Dimova, R. A1 - Cölfen, H. A1 - Meier, W. A1 - Schlaad, H. A1 - Taubert, A. T1 - Solution behavior of double-hydrophilic block copolymers in dilute aqueous solution N2 - The self-assembly of double-hydrophilic poly(ethylene oxide)–poly(2-methyl-2-oxazoline) diblock copolymers in water has been studied. Isothermal titration calorimetry, small-angle X-ray scattering, and analytical ultracentrifugation suggest that only single polymer chains are present in solution. In contrast, light scattering and transmission electron microscopy detect aggregates with radii of ca. 100 nm. Pulsed field gradient NMR spectroscopy confirms the presence of aggregates, although only 2% of the polymer chains undergo aggregation. Water uptake experiments indicate differences in the hydrophilicity of the two blocks, which is believed to be the origin of the unexpected aggregation behavior (in accordance with an earlier study by Ke et al. [Macromolecules2009, 42, 5339–5344]). The data therefore suggest that even in double-hydrophilic block copolymers, differences in hydrophilicity are sufficient to drive polymer aggregation, a phenomenon that has largely been overlooked or ignored so far. KW - Nanotechnology KW - Small-angle X-ray scatering KW - SAXS PY - 2012 DO - https://doi.org/10.1021/ma300621g SN - 0024-9297 SN - 1520-5835 VL - 45 IS - 11 SP - 4772 EP - 4777 PB - American Chemical Society CY - Washington, DC AN - OPUS4-26072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, X.-D. A1 - Meier, R.J. A1 - Schmittlein, C. A1 - Schreml, S. A1 - Schäferling, Michael A1 - Wolfbeis, Otto S. T1 - A water-sprayable, thermogelating and biocompatible polymer host for use in fluorescent chemical sensing and imaging of oxygen, pH values and temperature N2 - We report on the use of a sprayable and thermogelating biomaterial (Poloxamer™; a.k.a. Pluronic™) in optical imaging of pH values, local oxygen and temperature. The material is highly biocompatible and easy to handle. We also show that the material is well permeable to oxygen (thus making it a good choice for use in oxygen sensors), and is stable in liquid solution and at elevated temperature. We demonstrate its applicability in optical sensors for oxygen, pH and temperature. This was accomplished by incorporating appropriate luminescent probes in various kinds of microparticles (which act as hosts for the probes and prevent dye leaching and aggregation), and then dispersing the microparticles in the thermogelating polymer. The resulting sensor gels were deposited on the surface of interest via spraying at temperatures of <20 °C. At these temperatures, the gels adhere well to the target, even on uneven surfaces such as skin, wounds, and bacterial cultures. If temperature is risen to above 25 °C, the gels form a thin and soft but solid sensing layer which, however, can be simply removed from surface of interest by cooling and wiping it off, or by washing with water. Sprayable thermogelating sensors present obvious advantages over other sensors by not causing damage to the surface of interest. In our perception, the sensing materials also have wide further applicability in sensors for other species including clinically relevant gases, enzyme substrates (such as glucose or lactate) and ions. KW - Chemical sensing KW - Imaging KW - Biocompatible polymer KW - Sprayable sensor KW - Fluorescence KW - Poloxamer KW - Pluronic KW - Oxygen sensor KW - pH sensor KW - Temperature sensor PY - 2015 DO - https://doi.org/10.1016/j.snb.2015.05.082 SN - 0925-4005 SN - 1873-3077 VL - 221 SP - 37 EP - 44 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-33855 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ondrus, V. A1 - Meier, R.J. A1 - Klein, C. A1 - Henne, U. A1 - Schäferling, Michael A1 - Beifuss, U. T1 - Europium 1,3-di(thienyl)propane-1,3-diones with outstanding properties for temperature sensing N2 - The synthesis of novel Eu complexes with 1,3-di(thienyl)propane-1,3-diones as ligands as well as their luminescence properties in different polymers are reported. The new temperature sensitive paints (TSPs) exhibit not only exceptional high temperature sensitivity over a wide range of temperatures but are also characterized by negligible pressure sensitivity and marked photostability. This is why they are outstandingly suitable for applications, e.g. in aerodynamics and hydrodynamics. KW - Temperature sensitive paint KW - Eu diketonate KW - Luminescence KW - Intensity method KW - Lifetime method PY - 2015 DO - https://doi.org/10.1016/j.sna.2015.07.023 SN - 0924-4247 VL - 233 SP - 434 EP - 441 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-33856 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nehring, R. A1 - Palivan, C.G. A1 - Moreno-Flores, S. A1 - Mantion, Alexandre A1 - Tanner, P. A1 - Toca-Herrera, J.L. A1 - Thünemann, Andreas A1 - Meier, W. T1 - Protein decorated membranes by specific molecular interactions N2 - Here we characterize new metal-functionalized amphiphilic diblock copolymers, developed for both surface and solution molecular recognition applications. Polybutadiene-block-poly(ethylene oxide) copolymers functionalized with nitrilotriacetic acid and tris(nitrilotriacetic acid) were complexed with nickel(II) to obtain coordination sites for oligohistidine residues of model proteins. Mixtures of functionalized polymers with the respective non-functionalized block copolymers self-assemble in aqueous solution into vesicular structures with a controlled density of the metal end-groups on their surface. In solution, binding of His6-tagged green fluorescent protein (EGFP) and red fluorescent protein (RFP) to the vesicle surface was quantified by fluorescence correlation spectroscopy. Small-angle X-ray scattering indicates an increase of the membrane thickness by 2-3 nm upon protein binding. Block copolymer monolayers at the air-water interface and on solid support served as a model system to characterize the protein-decorated membranes by Brewster angle microscopy and AFM. High resolution AFM of solid-supported, hydrated monolayers indicates that the proteins form densely packed and partially ordered arrays with the cylindrically shaped EGFP molecules lying flat on the surface of the films. KW - Amphiphilic copolymer KW - Metal centers KW - His-tag proteins KW - Molecular recognition PY - 2010 DO - https://doi.org/10.1039/c002838j SN - 1744-683X VL - 6 SP - 2815 EP - 2824 PB - RSC Publ. CY - Cambridge AN - OPUS4-21564 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -