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

Abstract

Abstract

Nanophase alpha-alumina and hydroxyapatite (HA) composites with and without CaF₂ were prepared and sintered at 1100°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 CaF₂. The addition of CaF₂ 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 CaF₂ additions were biocompatible. CaF₂ addition into the composites improved cell attachment and proliferation after 3 days of culture.

Keywords:

• Bioceramics
• Sintering
• X-ray scattering
• Phase transitions

The authors would like to thank the Middle East Technical University BAP project (project no. 2005-03-10-03) for the financial support.