title: Rietveld structure and in vitro analysis on the influence of magnesium in biphasic (hydroxyapatite and beta-tricalcium phosphate) mixtures.
abstract: The structure of two different Mg-substituted biphasic (HAP and beta-TCP) mixtures along with the biphasic mixtures without substituted Mg(2+) was investigated using Rietveld refinement technique. The substituted Mg(2+) was found in the beta-TCP phase and its influence on the composition has led to an increase in HAP content of Mg-containing biphasic mixtures when compared with the HAP content detected in pure biphasic mixtures. The refined structural parameters of Ca(10)(PO(4))(6)(OH)(2) and beta-Ca(3)(PO(4))(2) confirmed that all the investigated compositions have crystallized in the corresponding hexagonal (space group P6(3)/m) and rhombohedral (space group R3c) structures. The substitution of lower sized magnesium was found preferentially incorporated at the sixfold-coordinated Ca (5) site of beta-TCP, which is due to the strong Ca (5).O interaction among all the five different Ca sites of beta-Ca(3)(PO(4))(2). The in vitro tests using primary culture of osteoblasts showed that all the tested samples are biocompatible and promising materials for in vivo studies.
authors.affiliation: Department of Ceramics and Glass Engineering, University of Aveiro, CICECO, 3810-193 Aveiro, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Kannan
authors.forename: F
authors.initials: F
authors.lastname: Goetz-Neunhoeffer
authors.forename: J
authors.initials: J
authors.lastname: Neubauer
authors.forename: A H S
authors.initials: AH
authors.lastname: Rebelo
authors.forename: P
authors.initials: P
authors.lastname: Valério
authors.forename: J M F
authors.initials: JM
authors.lastname: Ferreira
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001672:Biocompatible Materials; D002130:Calcium Phosphates / Q000737:chemistry*; D002478:Cells, Cultured; D017886:Durapatite / Q000737:chemistry*; D066298:In Vitro Techniques; D008274:Magnesium / Q000737:chemistry*; D010006:Osteoblasts / Q000166:cytology / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D017886:Durapatite; D000469:Alkaline Phosphatase; D008274:Magnesium; C018392:tricalcium phosphate