resumo
Si-hydroxyapatite (Si-HAP) has been used in orthopedic, dental, and maxillofacial surgery as a bone substitute. Objective. The aim of this investigation was to study the effect of Si substitution into the hydroxyapatite matrices and evaluate the biocompatibility effects of Si-HAP material in vitro with human osteoblasts. Methods. Silicon-substituted hydroxyapatite (Si-HAP) bioceramic materials were prepared by incorporating small amounts of silicon into the structure of hydroxyapatite [Ca-10(PO4)(6)(OH)(2), HAP] through a sol-gel method. A series of silicon substitutions ranging from 0, 1, 3 and S mol%, which are comparable to the measured silicon contents in natural bone, were performed. Results. Single-phase Si-HAP was obtained upon calcining the as-prepared powders up to 800 C since no secondary phases, such as tricalcium phosphate (TCP), tetracalcium phosphate (TeCP) or calcium oxide (CaO), were identified by X-ray diffraction analysis. The effects of silicon-substituted hydroxyapatite (Si-HAP) materials towards the responses of human osteoblast-like (HOB) cells were investigated and compared with pure hydroxyapatite. Significance. The Si-HAP indicated a significant increase in cell growth density with culture time irrespective of the amount of Si substituted in HAP. A high Si content (5 mol%) appears to promote rapid bone mineralization, since large amount of calcium phosphate minerals started to develop across the ECM by day 31 for a sample containing 5 mol% Si. On the other hand, a high Si content may result in fast dissolution of the material, owing to a decrease of HAP crystallite size, which might not be ideal for cell attachment for prolonged time periods. An optimum level of Si appears to exist at 3 mol%, which balances these effects. (C) 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
palavras-chave
THIN-FILMS; SILICON
categoria
Dentistry, Oral Surgery & Medicine; Materials Science
autores
Balamurugan, A; Rebelo, AHS; Lemos, AF; Rocha, JHG; Ventura, JMG; Ferreira, JMF
nossos autores
Isabel Alexandra Fernandes Lemos
Bolseiro de pós-Doutoramento
João Rocha
Prof. Catedrático
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)agradecimentos
The work was supported by CICECO, University of Aveiro, Portugal. The authors would like to acknowledge the support and technical assistance of Prof. D. Laurent-Maquin, Director, INSERM ERM0203 and Centre for Bioactive Materials and Tissue Engineering, University of Reims, France.