@article{SalamaNeumannGuenteretal.2014, author = {Salama, Ahmed and Neumann, Mike and G{\"u}nter, Christina and Taubert, Andreas}, title = {Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials}, series = {Beilstein journal of nanotechnology}, volume = {5}, journal = {Beilstein journal of nanotechnology}, publisher = {Beilstein-Institut zur F{\"o}rderung der Chemischen Wissenschaften}, address = {Frankfurt, Main}, issn = {2190-4286}, doi = {10.3762/bjnano.5.167}, pages = {1553 -- 1568}, year = {2014}, abstract = {Cellulose/calcium phosphate hybrid materials were synthesized via an ionic liquid-assisted route. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis/differential thermal analysis show that, depending on the reaction conditions, cellulose/hydroxyapatite, cellulose/ chlorapatite, or cellulose/monetite composites form. Preliminary studies with MC3T3-E1 pre-osteoblasts show that the cells proliferate on the hybrid materials suggesting that the ionic liquid-based process yields materials that are potentially useful as scaffolds for regenerative therapies.}, language = {en} } @article{MaiRakhmatullinaBleeketal.2014, author = {Mai, Tobias and Rakhmatullina, Ekaterina and Bleek, Katrin and Boye, Susanne and Yuan, Jiayin and Voelkel, Antje and Graewert, Marlies and Cheaib, Zeinab and Eick, Sigrun and G{\"u}nter, Christina and Lederer, Albena and Lussi, Adrian and Taubert, Andreas}, title = {Poly(ethylene oxide)-b-poly(3-sulfopropyl methacrylate) block copolymers for calcium phosphate mineralization and biofilm inhibition}, series = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences}, volume = {15}, journal = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences}, number = {11}, publisher = {American Chemical Society}, address = {Washington}, issn = {1525-7797}, doi = {10.1021/bm500888q}, pages = {3901 -- 3914}, year = {2014}, abstract = {Poly(ethylene oxide) (PEO) has long been used as an additive in toothpaste, partly because it reduces biofilm formation on teeth. It does not, however, reduce the formation of dental calculus or support the remineralization of dental enamel or dentine. The present article describes the synthesis of new block copolymers on the basis of PEO and poly(3-sulfopropyl methacrylate) blocks using atom transfer radical polymerization. The polymers have very large molecular weights (over 10(6) g/mol) and are highly water-soluble. They delay the precipitation of calcium phosphate from aqueous solution but, upon precipitation, lead to relatively monodisperse hydroxyapatite (HAP) spheres. Moreover, the polymers inhibit the bacterial colonization of human enamel by Streptococcus gordonii, a pioneer bacterium in oral biofilm formation, in vitro. The formation of well-defined HAP spheres suggests that a polymer-induced liquid precursor phase could be involved in the precipitation process. Moreover, the inhibition of bacterial adhesion suggests that the polymers could be utilized in caries prevention.}, language = {en} } @article{ZobirAltenbergerGuenter2014, author = {Zobir, Soraya Hadj and Altenberger, Uwe and G{\"u}nter, Christina}, title = {Geochemistry and petrology of metamorphosed submarine basic ashes in the Edough Massif (Cap de Garde, Annaba, northeastern Algeria)}, series = {Comptes rendus geoscience}, volume = {346}, journal = {Comptes rendus geoscience}, number = {9-10}, publisher = {Elsevier}, address = {Paris}, issn = {1631-0713}, doi = {10.1016/j.crte.2014.09.002}, pages = {244 -- 254}, year = {2014}, abstract = {The study presents the first evidence of metamorphosed submarine ashes in the Edough Massif, in northeastern Algeria. It occurs below the greenschist-facies Tellian units that represent the thrusted Mesozoic to Eocene passive paleomargin of northern Africa deposited on thinned continental crust. The metamorphic complex consists of tectonically superposed units composed of gneisses (lower unit) and micaschists (upper unit). At the Cap de Garde, these units enclose an "intermediate unit" composed of micaschists and meter-thick layers of marbles, which are sometimes intercalated with amphibolites. The latter occur as discontinuous small lenses and layers. The amphibolites are parallel to the primary bedding of the marbles and the main foliation. Chemical markers and field observations indicate that they are metamorphic equivalents of basic igneous rocks. The lenticular character, low thickness and multiple intercalations with marine sediments and the unusual high lithium concentrations suggest subaqueous near-source basaltic ash-fall deposits in a marine environment. (C) 2014 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.}, language = {en} }