resumo
The influence of ionic substituents in calcium phosphates intended for bone and tooth replacement biomedical applications is an important research topic, owing to the essential roles played by trace elements in biological processes. The present study investigates the mechanical and biological evaluation of ionic doped hydroxyapatite/beta-tricalcium phosphate mixtures which have been prepared by a simple aqueous precipitation method. Heat treating the resultant calcium phosphates in a carbonated atmosphere led to the formation of ionic doped carbonated hydroxyapatite/beta-tricalcium phosphate mixtures containing the essential ions of biological apatite. The structural analysis determined by Rietveld refinement confirmed the presence of hydroxyapatite as the main phase, together with a considerable amount of beta-tricalcium phosphate. Such phase assemblage is essentially due to the influence of substituted ions during synthesis. The results from mechanical tests proved that carbonate substitutions are detrimental for the mechanical properties of apatite-based ceramics. In vitro proliferation assays of osteoblastic-like cells (MC3T3-E1 cell line) to powders revealed that carbonate incorporation can either delay or accelerate MC3T3 proliferation, although reaching the same proliferation levels as control cells after 2 weeks in culture. Further, the powders enable pre-osteoblastic differentiation in a similar manner to control cells, as indirectly measured by ALP activity and Type-I collagen medium secretion. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
palavras-chave
CO-SUBSTITUTED HYDROXYAPATITES; CALCIUM-PHOSPHATE; ALKALINE-PHOSPHATASE; BIPHASIC HYDROXYAPATITE; CRYSTAL-STRUCTURE; APATITE; MAGNESIUM; FLUORINE; SODIUM; CELLS
categoria
Engineering; Materials Science
autores
Kannan, S; Vieira, SI; Olhero, SM; Torres, PMC; Pina, S; Silva, OABDE; Ferreira, JMF
nossos autores
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)
Paula Maria da Costa Torres
Investigador Auxiliar
Susana Maria Henriques Olhero
Professor Auxiliaragradecimentos
The authors thank CICECO, University of Aveiro, for financial support, and also FCT for the fellowship grants to S.I.V. (SFRH/BPD/19515/2004), S.M.O. (SFRH/BPD/27013/2006), P.M.C.T. (SFRH/BD/62021/2009) and S.P. (SFRH/BD/BPD/64119/2009).