Synthesis, phase transitions and cellular biocompatibility of nanophase alumina-hydroxyapatite composites

Nanophase alpha-alumina and hydroxyapatite (HA) composites with and without CaF(2) were prepared and sintered at 1100 degrees C for 1 h to investigate their densification, structural and biocompatibility properties. X-ray diffraction method was performed to examine the second phases in the materials. It was observed that HA slightly decomposed into tricalcium phosphate and CaO with the addition of CaF(2). The addition of CaF(2) also resulted in an increase in the density of the composites. The composites were then evaluated for their biocompatibility using cytotoxicity tests. Saos-2 cells were seeded on composite discs in order to investigate the cellular responses to materials in terms of morphology, attachment and proliferation using scanning electron microscopy and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-2H-tetrazolium-bromide viability assays. Cell culture studies showed that the nano-alumina and HA composite discs with or without CaF(2) additions were biocompatible. CaF(2) addition into the composites improved cell attachment and proliferation after 3 days of culture.


Microstructural, mechanical, and osteocompatibility properties of Mg2+/F--doped nanophase hydroxyapatite
Sun, Zehra Pinar; Ercan, Batur; Evis, Zafer; Webster, Thomas J. (Wiley, 2010-09-01)
Pure as well as Mg2+- and F--doped nanophase (i.e., grain sizes in the nanometer regime in at least one dimension) hydroxyapatite (HA) samples were synthesized by a precipitation method followed by sintering at 1100 degrees C for 1 h to determine their microstructural, mechanical, and osteoblast (bone-forming cell) adhesion properties pertinent for orthopedic applications. Different amounts of Mg2+ and F- ions (specifically from 0 to 7.5 mol %) were doped into the HA samples. X-ray diffraction was used to i...
Improvement in sinterability and phase stability of hydroxyapatite and partially stabilized zirconia composites
Evis, Zafer; KUTBAY, IŞIL (Elsevier BV, 2009-03-01)
Composites of hydroxyapatite with partially stabilized zirconia with MgO or MgF2 were pressureless sintered between 1000 degrees C and 1300 degrees C. The reactions and transformations of phases were verified by X-ray diffraction. For the hydroxyapatite and zirconia composites with MgO, calcium from the hydroxyapatite diffused into the zirconia phase, and the hydroxyapatite decomposed to tri-calcium phosphate at sintering temperatures higher than 1000 degrees C. Above about 1200 degrees C, CaZrO3 was formed...
Quantum-chemical treatment of the linoleic acid molecule and two of its conjugated isomers
Kurban, Sevil; ERKOÇ, Figen; Erkoç, Şakir (Wiley, 2009-10-01)
The structural, vibrational and electronic properties of die linoleic acid molecule and two of its conjugated isomers were investigated theoretically by performing the molecular mechanics (MM+ force field), the semi-empirical self-consistent-field molecular-orbital (PM3), and the density functional theory (B3LYP) calculations. The geometries of the considered molecules were optimized; the vibrational dynamics and the electronic properties were calculated in their ground states in the gas phase. It was found...
Activity-corn position relations in MuCr(2)O(4)-CoCr2O4 solid solutions and stabilities of MnCr2O4 and CoCr2O4 at 1300 degrees C
Koc, N; Timucin, M (Wiley, 2005-09-01)
Phase equilibria in the system MnO-CoO-Cr2O3 were investigated at 1300 degrees C under controlled oxygen partial pressures by using the gas equilibration technique. The CoO activities in various phase assemblages of the system were measured by determining the partial pressures of oxygen in the gas phase for coexistence with metallic cobalt. The activity data revealed that at 1300 degrees C, MnO-CoO and MnCr2O4-CoCr2O4 solid solutions exhibit mild positive departures from ideal behavior. The activities in th...
Impact modified polyamide-6/organoclay nanocomposites: Processing and characterization
Isik, Isil; YILMAZER, ÜLKÜ; Bayram, Göknur (Wiley, 2008-02-01)
The effects of melt state compounding of ethylene-butyl acrylate-maleic anhydride (E-BA-MAH) terpolymer and/or three types of organoclays (Cloisitel(R) 15A, 25A, and 3013) on thermal and mechanical properties and morphology of polyamide-6 are investigated. E-BA-MAH formed spherical domains in the materials to which it is added, and increased the impact strength, whereas the organoclays decreased the impact strength. In general, the organoclays increased the tensile strength (except for Cloisite 15A), Young'...
Citation Formats
B. BAŞAR, A. Tezcaner, D. Keskin, and Z. Evis, “Synthesis, phase transitions and cellular biocompatibility of nanophase alumina-hydroxyapatite composites,” ADVANCES IN APPLIED CERAMICS, pp. 238–243, 2011, Accessed: 00, 2020. [Online]. Available: