title: Nano-porous calcium phosphate balls.
abstract: By dropping a NaH2PO4·H2O precursor solution to a CaCl2 solution at 90°C under continuous stirring in presence of two biopolymers, i.e. gelatin (G) and chitosan (C), supramolecular calcium phosphate (CP) card house structures are formed. Light microscopic investigations in combination with scanning electron microscopy show that the GC-based flower-like structure is constructed from very thin CP platelets. Titration experiments indicate that H-bonding between both biopolymers is responsible for the synergistic effect in presence of both polymers. Gelatin-chitosan-water complexes play an important role with regard to supramolecular ordering. FTIR spectra in combination with powder X-ray diffraction show that after burning off all organic components (heating up >600°C) dicalcium and tricalcium phosphate crystallites are formed. From high resolution transmission electron microscopy (HR-TEM) it is obvious to conclude, that individual crystal platelets are dicalcium phosphates, which build up ball-like supramolecular structures. The results reveal that the GC guided crystal growth leads to nano-porous supramolecular structures, potentially attractive candidates for bone repair.
authors.affiliation: Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Germany.
authors.forename: Ildyko
authors.initials: I
authors.lastname: Kovach
authors.affiliation: Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Kosmella
authors.affiliation: Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Prietzel
authors.affiliation: Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Bagdahn
authors.affiliation: Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Germany. Electronic address: koetz@uni-potsdam.de.
authors.forename: Joachim
authors.initials: J
authors.lastname: Koetz
mesh_terms: D002130:Calcium Phosphates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D058608:Nanopores; D033362:Powder Diffraction; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry
chemical_list: D002130:Calcium Phosphates; C020243:calcium phosphate
keywords: Biomineralization; Bone repair material; Calcium phosphates; Supramolecular ball structure