@article{GoebelHesemannWeberetal.2009,
  author    = {Goebel, Ronald and Hesemann, Peter and Weber, Jens and Moeller, El{\´e}onore and Friedrich, Alwin and Beuermann, Sabine and Taubert, Andreas},
  title     = {Surprisingly high, bulk liquid-like mobility of silica-confined ionic liquids},
  issn      = {1463-9076},
  doi       = {10.1039/B821833a},
  year      = {2009},
  abstract  = {Mesoporous silica monoliths were prepared by the sol - gel technique and. lled with 1-ethyl-3-methyl imidazolium [Emim]-X (X = dicyanamide [N(CN)(2)], ethyl sulfate [EtSO4], thiocyanate [SCN], and triflate [TfO]) ionic liquids (ILs) using a methanol-IL exchange technique. The structure and behavior of the ILs inside the silica monoliths were studied using X-ray scattering, nitrogen sorption, IR spectroscopy, solid-state NMR, and thermal analysis. DSC finds shifts in both the glass transition temperature and melting points (where applicable) of the ILs. Glass transition and melting occur well below room temperature. There is thus no conflict with the NMR and IR data, which show that the ILs are as mobile at room temperature as the bulk (not confined) ILs. The very narrow line widths of the NMR spectra suggest that the ILs in our materials have the highest mobility reported for confined ILs so far. As a result, our data suggest that it is possible to generate IL/silica hybrid materials (ionogels) with bulk-like properties of the IL. This could be interesting for applications in, e.g., the solar cell or membrane fields.},
  language  = {en}
}
@article{KindPlamperGoebeletal.2009,
  author    = {Kind, Lucy and Plamper, Felix A. and Goebel, Ronald and Mantion, Alexandre and Mueller, Axel H. E. and Pieles, Uwe and Taubert, Andreas and Meier, Wolfgang P.},
  title     = {Silsesquioxane/polyamine nanoparticle-templated formation of star- or raspberry-like silica nanoparticles},
  issn      = {0743-7463},
  doi       = {10.1021/La900229n},
  year      = {2009},
  abstract  = {Silica is an important mineral in biology and technology, and many protocols have been developed for the synthesis of complex silica architectures. The current report shows that silsesquioxane nanoparticles carrying polymer arms on their surface are efficient templates for the fabrication of silica particles with a star- or raspberry-like morphology. The shape of the resulting particles depends on the chemistry of the polymer arms. With poly(N,N- dimethylaminoethyl methacrylate) (PDMAEMA) arms, spherical particles with a less electron dense core form. With poly {[2- (methacryloyloxy)ethyl] trimethylammonium iodide} (PMETAI), star- or raspberry-like particles form. Electron microscopy, electron tomography, and small-angle X-ray scattering show that the resulting silica particles have a complex structure, where a silsequioxane nanoparticle carrying the polymer arms is in the center. Next is a region that is polymer-rich. The outermost region of the particle is a silica layer, where the outer parts of the polymer arms are embedded. Time- resolved zeta-potential and pH measurements, dynamic light scattering, and electron microscopy reveal that silica formation proceeds differently if PDMAEMA is exchanged for PMETAI.},
  language  = {en}
}
@article{GrafMantionFoelskeetal.2009,
  author    = {Graf, Philipp and Mantion, Alexandre and Foelske, Annette and Shkilnyy, Andriy and Ma{\"U}ic, Admir and Thuenemann, Andreas F. and Taubert, Andreas},
  title     = {Peptide-coated silver nanoparticles : synthesis, surface chemistry, and pH-triggered, reversible assembly into particle assemblies},
  issn      = {0947-6539},
  doi       = {10.1002/chem.200802329},
  year      = {2009},
  abstract  = {Simple tripeptides are scaffolds for the synthesis and further assembly of peptide/silver nanoparticle composites. Herein, we further explore peptide-con trolled silver nanoparticle assembly processes. Silver nanoparticles with a pH-responsive peptide coating have been synthesized by using a one-step precipitation/coating route. The nature of the peptide/silver interaction and the effect of the peptide oil the formation of the silver particles have been studied via UV/Vis, X-ray photoelectron, and surface-enhanced Raman spectroscopies as well as through electron microscopy, small angle X-ray scattering and powder Xray diffraction with Rietveld refinement. The particles reversibly form aggregates of different sizes in aqueous solution. The state of aggregation call be controlled by the solution pH value. At low pH values, individual particles are present. At neutral pH values, small clusters form and at high pH values, large precipitates are observed.},
  language  = {en}
}
@article{NavarroShkilnyyTierschetal.2009,
  author    = {Navarro, Salvador and Shkilnyy, Andriy and Tiersch, Brigitte and Taubert, Andreas and Menzel, Henning},
  title     = {Preparation, characterization, and thermal gelation of amphiphilic alkyl-poly(ethyleneimine)},
  issn      = {0743-7463},
  doi       = {10.1021/La9013569},
  year      = {2009},
  abstract  = {Amphiphilic alkyl-poly(ethyleneimine)s (alkyl-PEI) with different degrees of polymerization have been produced by alkaline hydrolysis of alkyl-poly(2-methyl-2-oxazoline). Potentiometric titration of the alkyl-PEI shows the influence of the alkyl chain and the degree of polymerization on the titration curves and hence on the polymer conformation. Karl Fischer titration has been used to determine the water content in the polymers. Subsequent X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) measurements prove the existence of different hydration states of the PEI even under dry storage conditions. Upon cooling from hot aqueous Solutions, hydrogels form. The gelation concentration decreases with increasing degree of polymerization of the PEI segment. Scanning electron microscopy (SEM and cryo-SEM) of the hydrogels reveal an alkyl-PEI fibrous network composed of fan-like units. DSC shows that the percentages of bound and free water in the hydrogels depend on the concentration of polar amino groups.},
  language  = {en}
}
@article{SchweizerSchusterJungingeretal.2010,
  author    = {Schweizer, S. and Schuster, T. and Junginger, Matthias and Siekmeyer, Gerd and Taubert, Andreas},
  title     = {Surface modification of ickel/Titanium Alloy and Titanium Surfaces via a Polyelectrolyte Multilayer/Calcium Phosphate Hybrid Coating},
  issn      = {1438-7492},
  doi       = {10.1002/mame.200900347},
  year      = {2010},
  abstract  = {The report shows that simple LbL deposition of positively charged chitosan and negatively charged heparin can be used to efficiently modify the native surface of both NiTi and Ti without any previous treatments. Moreover, mineralization of the polymer multilayers with calcium phosphate leads to surfaces with low contact angles around 70 and 20 degrees for NiTi and Ti, respectively. This suggests that a polymer multilayer/calcium phosphate hybrid coating could be useful for making NiTi or Ti implants that are at the same time antibacterial (via the chitosan), suppress blood clot formation (via the heparin), and favor fast endothelialization (via the improved surface hydrophilicity compared to the respective neat material).},
  language  = {en}
}
@article{ShkilnyyBrandtMantionetal.2009,
  author    = {Shkilnyy, Andriy and Brandt, Jessica and Mantion, Alexandre and Paris, Oskar and Schlaad, Helmut and Taubert, Andreas},
  title     = {Calcium phosphate with a channel-like morphology by polymer templating},
  issn      = {0897-4756},
  doi       = {10.1021/Cm803244z},
  year      = {2009},
  abstract  = {Calcium phosphate mineralization from aqueous solution in the presence of organic growth modifiers has been intensely studied in the recent past. This is mostly due to potential applications of the resulting composites in the biomaterials field. Polymers in particular are efficient growth modifiers. As a result, there has been a large amount of work on polymeric growth modifiers. Interestingly, however, relatively little work has been done on polycationic additives. The current paper shows that poly(ethylene oxide)b-poly(L-lysine) block copolymers lead to an interesting morphology of calcium phosphate precipitated at room temperature and subjected to a mild heat treatment at 85 degrees C. Electron microscopy, synchrotron X-ray diffraction, and porosity analysis show that a (somewhat) porous material with channel-like features forms. Closer inspection using transmission electron microscopy shows that the channels are probably not real channels. Much rather the morphology is the result of the aggregation of ca. 100-nm-sized rodlike primary particles, which changes upon drying to exhibit the observed channel-like features. Comparison experiments conducted in the absence of polymer and with poly(ethylene oxide)-b-poly(L-glutamate) show that these features only form in the presence of the polycationic poly(L-lysine) block, suggesting a distinct interaction of the polycation with either the crystal or the phosphate ions prior to mineralization.},
  language  = {en}
}
@article{BagdahnTaubert2013,
  author    = {Bagdahn, Christian and Taubert, Andreas},
  title     = {Ionogel fiber mats - functional materials via electrospinning of PMMA and the ionic liquid bis(1-butyl-3-methyl-imidazolium) Tetrachloridocuprate(II), [Bmim](2)[CuCl4]},
  series = {Zeitschrift f{\"u}r Naturforschung : B, Chemical sciences},
  volume    = {68},
  journal   = {Zeitschrift f{\"u}r Naturforschung : B, Chemical sciences},
  number    = {10},
  publisher = {De Gruyter},
  address   = {T{\"u}bingen},
  issn      = {0932-0776},
  doi       = {10.5560/ZNB.2013-3195},
  pages     = {1163 -- 1171},
  year      = {2013},
  abstract  = {Ionogel fiber mats were made by electrospinning poly(methylmethacrylate) (PMMA) and the ionic liquid (IL) bis(1-butyl-3-methyl-imidazolium) tetrachloridocupraten, [Bmim](2)[CuCl4], from acetone. The morphology of the electrospun ionogels strongly depends on the spinning parameters. Dense and uniform fiber mats were only obtained at concentrations of 60 to 70 g of polymer and IL mass combined. Lower concentrations led to a low number of poorly defined fibers. High voltages of 20 to 25 kV led to well-defined and uniform fibers; voltages between 15 and 20 kV again led to less uniform and less dense fibers. At 10 kV and lower, no spinning could be induced. Finally, PMMA fibers electrospun without IL show a less well-defined morphology combining fibers and oblong droplets indicating that the IL has a beneficial effect on the electrospinning process. The resulting materials are prototypes for new functional materials, for example in sterile filtration.},
  language  = {en}
}
@article{AyiKhareStrauchetal.2010,
  author    = {Ayi, Ayi A. and Khare, Varsha and Strauch, Peter and Girard, J{\`e}r{\^o}me and Fromm, Katharina M. and Taubert, Andreas},
  title     = {On the chemical synthesis of titanium nanoparticles from ionic liquids},
  issn      = {0026-9247},
  doi       = {10.1007/s00706-010-0403-4},
  year      = {2010},
  abstract  = {We report on attempts towards the synthesis of titanium nanoparticles using a wet chemical approach in imidazolium-based ionic liquids (ILs) under reducing conditions. Transmission electron microscopy finds nanoparticles in all cases. UV/Vis spectroscopy confirms the nanoparticulate nature of the precipitate, as in all cases an absorption band between ca. 280 and 300 nm is visible. IR spectroscopy shows that even after extensive washing and drying, some IL remains adsorbed on the nanoparticles. Raman spectroscopy suggests the formation of anatase nanoparticles, but X-ray diffraction reveals that, possibly, amorphous titania forms or that the nanoparticles are so small that a clear structure assignment is not possible. The report thus shows that (possibly amorphous) titanium oxides even form under reducing conditions and that the chemical synthesis of titanium nanoparticles in ILs remains elusive.},
  language  = {en}
}
@article{HaaseRottMantionetal.2012,
  author    = {Haase, Andrea and Rott, Stephanie and Mantion, Alexandre and Graf, Philipp and Plendl, Johanna and Th{\"u}nemann, Andreas F. and Meier, Wolfgang P. and Taubert, Andreas and Luch, Andreas and Reiser, Georg},
  title     = {Effects of silver nanoparticles on primary mixed neural cell cultures: Uptake, oxidative stress and acute calcium responses},
  series = {Toxicological sciences},
  volume    = {126},
  journal   = {Toxicological sciences},
  number    = {2},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {1096-6080},
  doi       = {10.1093/toxsci/kfs003},
  pages     = {457 -- 468},
  year      = {2012},
  abstract  = {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 mu g/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 mu g/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.},
  language  = {en}
}
@article{HaaseMantionGrafetal.2012,
  author    = {Haase, A. and Mantion, A. and Graf, P. and Plendl, J. and Th{\"u}nemann, Andreas F. and Meier, Wolfgang P. and Taubert, Andreas and Luch, A.},
  title     = {A novel type of silver nanoparticles and their advantages in toxicity testing in cell culture systems},
  series = {Archives of toxicology : official journal of EUROTOX},
  volume    = {86},
  journal   = {Archives of toxicology : official journal of EUROTOX},
  number    = {7},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0340-5761},
  doi       = {10.1007/s00204-012-0836-0},
  pages     = {1089 -- 1098},
  year      = {2012},
  abstract  = {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.},
  language  = {en}
}