New Nanocomposite System with Nanocrystalline Apatite Embedded into Mesoporous Bioactive Glass

Crystalline nanoparticles are very attractive building blocks for the preparation of nanostructured materials. These particles can be dispersed in different noncrystalline mesostructured matrixes in order to obtain nanocomposite systems which combine the properties of both components broadening their functionality. In the present study, a novel nanocomposite bioceramic formed by nanocrystalline apatite particles uniformly embedded into a mesostructured SiO2-CaO-P2O5 glass wall has been synthesized through the evaporation-induced self-assembly (EISA) method, commonly used for mesoporous bioactive glass synthesis, but accelerating the sol gel apatite crystallization rate by strong acidification. Moreover, the use of F127 surfactant as a structure directing agent in this synthesis has allowed the homogeneous nanocrystalline apatite particles incorporation inside of the amorphous mesoporous glass. In vitro bioactive assays have shown a fast apatite-like phase formation similar to that exhibited by mesoporous bioactive glasses. Furthermore, the response of L929 fibroblasts and Saos-2 osteoblasts to this new nanocomposite has indicated a significant improvement in its biocompatibility compared with conventional mesoporous bioactive glasses.