3D biodegradable scaffolds of polycaprolactone with silicate-containing hydroxyapatite microparticles for bone tissue engineering: high-resolution tomography and in vitro study

To date, special interest has been paid to composite scaffolds based on polymers enriched with hydroxyapatite (HA). However, the role of HA containing different trace elements such as silicate in the structure of a polymer scaffold has not yet been fully explored. Here, we report the potential use of silicate-containing hydroxyapatite (SiHA) microparticles and microparticle aggregates in the predominant range from 2.23 to 12.40 µm in combination with polycaprolactone (PCL) as a hybrid scaffold with randomly oriented and well-aligned microfibers for regeneration of bone tissue. Chemical and mechanical properties of the developed 3D scaffolds were investigated with XRD, FTIR, EDX and tensile testing. Furthermore, the internal structure and surface morphology of the scaffolds were analyzed using synchrotron X-ray µCT and SEM. Upon culturing human mesenchymal stem cells (hMSC) on PCL-SiHA scaffolds, we found that both SiHA inclusion and microfiber orientation affected cell adhesion. The best hMSCs viability was revealed at 10 day for the PCL-SiHA scaffolds with well-aligned structure (~82%). It is expected that novel hybrid scaffolds of PCL will improve tissue ingrowth in vivo due to hydrophilic SiHA microparticles in combination with randomly oriented and well-aligned PCL microfibers, which mimic the structure of extracellular matrix of bone tissue

Author Correction: 3D biodegradable scaffolds of polycaprolactone with silicate-containing hydroxyapatite microparticles for bone tissue engineering: high-resolution tomography and in vitro study

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Redetermination of the crystal structure of K[BrF4] from single-crystal X-ray diffraction data

Single crystals of K[BrF4], potassium tetrafluoridobromate(III), were grown from a solution of KHF2 in bromine trifluoride. The current report is the first refinement of the crystal structure of K[BrF4] using single-crystal X-ray diffraction data. In comparison with previous refinements from powder data, the fractional coordinates of the F atom were determined with higher precision, and anisotropic displacement parameters were refined for all atoms. The structure contains square-planar [BrF4]− anions. The coordination polyhedron of the potassium cation is a square antiprism

Synthesis and Characterization of the Tetrafluoridochlorates(III) A[ClF4] (A = K, Rb, Cs)

Single-crystalline tetrafluoridochlorates(III) A[ClF4] (A = K, Rb, Cs) were synthesized from solvolysis reactions of alkali metal fluorides in liquid chlorine trifluoride. The structures were examined by means of single-crystal X-ray diffraction. K[ClF4] crystallizes in the K[BrF4] structure type, whereas the Rb and Cs compounds crystallize in the Li[AuF4] structure type. The compounds were further characterized by Raman and IR spectroscopy. Solid-state quantum-chemical calculations with hybrid density functional methods reproduced the experimental structures and enabled the interpretation of the experimental Raman and IR spectra.Peer reviewe

Synthesis and characterization of the pyridine—bromine trifluoride (1/1) complex, [py∙BrF3]

The pyridine—bromine trifluoride (1/1) complex was synthesized and characterized. It crystallizes in the monoclinic space group C2/c with a = 6.9044(9), b = 14.769(2), c = 6.9665(9) Å, β = 111.686(9)°, V = 660.12(16) Å3, Z = 4 at 100 K. The crystal structure consists of isolated non-planar molecules linked via C–H⋯F hydrogen bonds. The obtained results were confirmed by quantum chemical calculations, vibrational and NMR spectroscopy. Calculations of an isolated molecule in the gas phase showed that a planar conformation of the molecule with intramolecular C–H⋯F hydrogen bonds is stable.Peer reviewe

PbF[Br2F7], a Fluoridobromate(III) of a p-Block Metal

Lisää OAP kun lopullinen tullu tulos!/Maria 16.12.19The compound PbF[Br2F7] represents the first fluoridobromate(III) of a p-block element. It was synthesized in form of needle-shaped crystals among its colorless powder from the direct reaction of PbF2 with BrF3. Powder X-ray diffraction, IR and Raman spectroscopy show that it was obtained in almost pure form with Pb3F8 and Pb2F6 as by-products. The single crystal structure was determined by X-ray diffraction. PbF[Br2F7] crystallizes in space group P21/c (No. 14) with a = 4.3698(3), b = 13.3767(7), c = 12.0836(8) Å, β = 97.509(5)°, V = 700.27(8) Å3, Z = 4 at T = 100 K. PbF[Br2F7] decomposes above 50 °C due to loss of BrF3 and pure PbF2 remains. Quantum chemical calculations were performed on the crystal structure of the compound to assign the bands of the vibrational spectra and to obtain electron density difference maps that visualize the electron density around the Pb atoms. CHARDI calculations support the assignment of the oxidation states +II, +III, and –I to the Pb, Br, and F atoms, respectively.Non peer reviewe

The Crystal Structures of α- and β-F 2 Revisited

The crystal structures of α-F 2 and β-F 2 have been reinvestigated using neutron powder diffraction. For the low-temperature phase α-F 2 , which is stable below circa 45.6 K, the monoclinic space group C2/c with lattice parameters a=5.4780(12), b=3.2701(7), c=7.2651(17) Å, β=102.088(18)°, V=127.26(5) Å 3 , mS8, Z=4 at 10 K can now be confirmed. The structure model was significantly improved, allowed for the anisotropic refinement of the F atom, and an F−F bond length of 1.404(12) Å was obtained, which is in excellent agreement with spectroscopic data and high-level quantum chemical predictions. The high-temperature phase β-F 2 , stable between circa 45.6 K and the melting point of 53.53 K, crystallizes in the cubic primitive space group Pm (Formula presented.) n with the lattice parameter a=6.5314(15) Å, V=278.62(11) Å 3 , cP16, Z=8, at 48 K. β-F 2 is isotypic to γ-O 2 and δ-N 2 . The centres of gravity of the F 2 molecules are arranged like the atoms in the Cr 3 Si structure type.Peer reviewe

Crystal Structures of α- And β-Nitrogen Trifluoride

The crystal structures of α-NF 3 and β-NF 3 are reported for the first time. As shown by powder neutron diffraction, the lowerature α-NF 3 crystallizes in the orthorhombic space group Pnma (oP16) with lattice parameters a = 6.71457(13) Å, b = 7.30913(14) Å, c = 4.55189(8) Å, V = 223.396(7) Å 3 , and Z = 4 at T = 6 K. The intramolecular atom distances in α-NF 3 are 1.3639(16) and 1.3677(11) Å for N-F, and 2.1216(16) and 2.120(2) Å for F···F. The F-N-F bond angles are 101.92(7)° and 101.63(10)°. All data are in excellent agreement with quantum-chemical predictions and previously reported experimentally obtained gas-phase data. The higherature β-NF 3 is a plastic crystal, space group P4 2 /mnm (tP120), with the lattice parameters a = 15.334(6) Å, c = 7.820(3) Å, V = 1838.6(12) Å 3 , and Z = 30 at T = 60 K. Its crystal structure is closely related to that of the Frank-Kasper sigma phase.Peer reviewe

A Neutron Diffraction and Quantum-Chemical Study of [Mn(ND3)6](N3)2

[Mn(ND3)6](N3)2 was obtained by careful decomposition of [Mn(ND3)6](N3)2·4ND3 at room temperature. It crystallizes in the monoclinic space group I2/m with a = 8.5905(5), b = 6.8506(4), c = 9.7530(6) Å, β = 94.618(6)°, V = 572.10(6) Å3, Z = 2, at T = 3 K. Its crystal structure was elucidated using powder neutron diffraction and confirmed by quantum chemical calculations. The MnII cation is coordinated octrahedron-like by ND3 ligands. The azide anion is linear with 178.7(10)° and shows N-N distances of 1.178(11) and 1.180(12) Å.Peer reviewe

A Symmetric F−H−F Hydrogen Bond in Strontium Bifluoride, Sr[HF2]2

Dataset CCDC 2117873, lisään kun landing page on auki Funding Information: We thank Dr. Matthias Conrad for helpful discussions and Solvay for generous donations of fluorine. T. G. thanks the HPC‐EUROPA3 (INFRAIA‐2016‐1‐730897) for a travel grant and the computing resources provided by CSC, the Finnish IT Center for Science. Open Access funding enabled and organized by Projekt DEAL. Publisher Copyright: © 2021 The Authors. Zeitschrift für anorganische und allgemeine Chemie published by Wiley-VCH GmbHSingle crystal X-ray diffraction shows the hydrogen bond within the [F−H−F]− anion of Sr[HF2]2 to be symmetric with H−F bond lengths of 1.143(5) Å and an intramolecular F⋅⋅⋅F distance of 2.2826(18) Å. The [HF2]− anion adopts crystallographic C2-symmetry, however, it is essentially linear with a F−H−F angle of 174(4)°. Solid-state quantum chemical calculations agree with the experimental findings, showing a slightly bent F−H−F angle of 177.8°. The decomposition of Sr[HF2]2 to SrF2 and HF is endothermic by +64 kJ/mol at room temperature. The bonding in the [F−H−F]− anion is clearly ionic both in the solid state and gas phase.Peer reviewe