@article{MaiWolskiPuciulMalinowskaetal.2018, author = {Mai, Tobias and Wolski, Karol and Puciul-Malinowska, Agnieszka and Kopyshev, Alexey and Gr{\"a}f, Ralph and Bruns, Michael and Zapotoczny, Szczepan and Taubert, Andreas}, title = {Anionic polymer brushes for biomimetic calcium phosphate mineralization}, series = {Polymers}, volume = {10}, journal = {Polymers}, number = {10}, publisher = {MDPI}, address = {Basel}, issn = {2073-4360}, doi = {10.3390/polym10101165}, pages = {17}, year = {2018}, abstract = {This article describes the synthesis of anionic polymer brushes and their mineralization with calcium phosphate. The brushes are based on poly(3-sulfopropyl methacrylate potassium salt) providing a highly charged polymer brush surface. Homogeneous brushes with reproducible thicknesses are obtained via surface-initiated atom transfer radical polymerization. Mineralization with doubly concentrated simulated body fluid yields polymer/inorganic hybrid films containing AB-Type carbonated hydroxyapatite (CHAP), a material resembling the inorganic component of bone. Moreover, growth experiments using Dictyostelium discoideum amoebae demonstrate that the mineral-free and the mineral-containing polymer brushes have a good biocompatibility suggesting their use as biocompatible surfaces in implantology or related fields.}, language = {en} } @misc{HentrichTauerEspanoletal.2017, author = {Hentrich, Doreen and Tauer, Klaus and Espanol, Montserrat and Ginebra, Maria-Pau and Taubert, Andreas}, title = {EDTA and NTA effectively tune the mineralization of calcium phosphate from bulk aqueous solution}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1095}, issn = {1866-8372}, doi = {10.25932/publishup-46918}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-469186}, pages = {23}, year = {2017}, abstract = {This study describes the effects of nitrilotriacetic acid (NTA) and ethylenediaminotetraacetic acid (EDTA) on themineralization of calciumphosphate from bulk aqueous solution. Mineralization was performed between pH 6 and 9 and with NTA or EDTA concentrations of 0, 5, 10, and 15 mM. X-ray diffraction and infrared spectroscopy show that at low pH, mainly brushite precipitates and at higher pH, mostly hydroxyapatite forms. Both additives alter the morphology of the precipitates. Without additive, brushite precipitates as large plates. With NTA, the morphology changes to an unusual rod-like shape. With EDTA, the edges of the particles are rounded and disk-like particles form. Conductivity and pH measurements suggest that the final products form through several intermediate steps.}, language = {en} } @article{HentrichTauerEspanoletal.2017, author = {Hentrich, Doreen and Tauer, Klaus and Espanol, Montserrat and Ginebra, Maria-Pau and Taubert, Andreas}, title = {EDTA and NTA effectively tune the mineralization of calcium phosphate from bulk aqueous solution}, series = {Biomimetics}, volume = {2}, journal = {Biomimetics}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2313-7673}, doi = {10.3390/biomimetics2040024}, pages = {21}, year = {2017}, abstract = {This study describes the effects of nitrilotriacetic acid (NTA) and ethylenediaminotetraacetic acid (EDTA) on themineralization of calciumphosphate from bulk aqueous solution. Mineralization was performed between pH 6 and 9 and with NTA or EDTA concentrations of 0, 5, 10, and 15 mM. X-ray diffraction and infrared spectroscopy show that at low pH, mainly brushite precipitates and at higher pH, mostly hydroxyapatite forms. Both additives alter the morphology of the precipitates. Without additive, brushite precipitates as large plates. With NTA, the morphology changes to an unusual rod-like shape. With EDTA, the edges of the particles are rounded and disk-like particles form. Conductivity and pH measurements suggest that the final products form through several intermediate steps.}, language = {en} } @article{HamedMisbahSantosQuintanillaetal.2017, author = {Hamed Misbah, Mohamed and Santos, Mercedes and Quintanilla, Luis and G{\"u}nter, Christina and Alonso, Matilde and Taubert, Andreas and Carlos Rodriguez-Cabello, Jose}, title = {Recombinant DNA technology and click chemistry: a powerful combination for generating a hybrid elastin-like-statherin hydrogel to control calcium phosphate mineralization}, series = {Beilstein journal of nanotechnology}, volume = {8}, 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.8.80}, pages = {772 -- 783}, year = {2017}, abstract = {Understanding the mechanisms responsible for generating different phases and morphologies of calcium phosphate by elastin-like recombinamers is supreme for bioengineering of advanced multifunctional materials. The generation of such multifunctional hybrid materials depends on the properties of their counterparts and the way in which they are assembled. The success of this assembly depends on the different approaches used, such as recombinant DNA technology and click chemistry. In the present work, an elastin-like recombinamer bearing lysine amino acids distributed along the recombinamer chain has been cross-linked via Huisgen [2 + 3] cycloaddition. The recombinamer contains the SN(A)15 peptide domains inspired by salivary statherin, a peptide epitope known to specifically bind to and nucleate calcium phosphate. The benefit of using click chemistry is that the hybrid elastin-like-statherin recombinamers cross-link without losing their fibrillar structure. Mineralization of the resulting hybrid elastin-like-statherin recombinamer hydrogels with calcium phosphate is described. Thus, two different hydroxyapatite morphologies (cauliflower- and plate-like) have been formed. Overall, this study shows that crosslinking elastin-like recombinamers leads to interesting matrix materials for the generation of calcium phosphate composites with potential applications as biomaterials.}, language = {en} } @phdthesis{Rusu2004, author = {Rusu, Viorel Marin}, title = {Composite materials made of chitosan and nanosized apatite : preparation and physicochemical characterization}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-2316}, school = {Universit{\"a}t Potsdam}, year = {2004}, abstract = {Taking inspiration from nature, where composite materials made of a polymer matrix and inorganic fillers are often found, e.g. bone, shell of crustaceans, shell of eggs, etc., the feasibility on making composite materials containing chitosan and nanosized hydroxyapatite were investigated. A new preparation approach based on a co-precipitation method has been developed. In its earlier stage of formation, the composite occurs as hydrogel as suspended in aqueous alkaline solution. In order to get solid composites various drying procedures including freeze-drying technique, air-drying at room temperature and at moderate temperatures, between 50oC and 100oC were used. Physicochemical studies showed that the composites exhibit different properties with respect to their structure and composition. IR and Raman spectroscopy probed the presence of both chitosan and hydroxyapatite in the composites. Hydroxyapatite as dispersed in the chitosan matrix was found to be in the nanosize range (15-50 nm) and occurs in a bimodal distribution with respect to its crystallite length. Two types of distribution domains of hydroxyapatite crystallites in the composite matrix such as cluster-like (200-400 nm) and scattered-like domains were identified by the transmission electron microscopy (TEM), X-ray diffraction (XRD) and by confocal scanning laser microscopy (CSLM) measurements. Relaxation NMR experiments on composite hydrogels showed the presence of two types of water sites in their gel networks, such as free and bound water. Mechanical tests showed that the mechanical properties of composites are one order of magnitude less than those of compact bone but comparable to those of porous bone. The enzymatic degradation rates of composites showed slow degradation processes. The yields of degradation were estimated to be less than 10\% by loss of mass, after incubation with lysozyme, for a period of 50 days. Since the composite materials were found biocompatible by the in vivo tests, the simple mode of their fabrication and their properties recommend them as potential candidates for the non-load bearing bone substitute materials.}, language = {en} }