Surface Characteristics of Nanocrystalline Apatites: Effect of Mg Surface Enrichment on Morphology, Surface Hydration Species, and Cationic Environments

Luca Bertinetti (1) , Christophe Drouet (2) , Christèle Combes (2) , Christian Rey (2) , Anna Tampieri , Salvatore Coluccia (1) , Gianmario Martra (1)

1 UNITO - Università degli studi di Torino = University of Turin
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

The incorporation of foreign ions, such as Mg2+, exhibiting a biological activity for bone regeneration is presently considered as a promising route for increasing the bioactivity of bone-engineering scaffolds. In this work, the morphology, structure, and surface hydration of biomimetic nanocrystalline apatites were investigated before and after surface exchange with suchMg2+ ions, by combining chemical alterations (ion exchange,H2OD2O exchanges) and physical examinations (Fourier transform infrared spectroscopy (FTIR) and highresolution transmission electron microscopy (HRTEM)). HRTEM data suggested that the Mg2+/Ca2+ exchange process did not affect the morphology and surface topology of the apatite nanocrystals significantly, while a new phase, likely a hydrated calcium and/or magnesium phosphate, was formed in small amount for high Mg concentrations. Near-infrared (NIR) and medium-infrared (MIR) spectroscopies indicated that the samples enriched withMg2+ were found to retain more water at their surface than the Mg-free sample, both at the level of H2O coordinated to cations and adsorbed in the form of multilayers. Additionally, the H-bonding network in defective subsurface layers was also noticeably modified, indicating that the Mg2+/Ca2+ exchange involved was not limited to the surface. This work is intended to widen the present knowledge on Mg-enriched calcium phosphate-based bioactive materials intended for bone repair applications.

Mots clés: Matériaux

Domaines: Matériaux

Luca Bertinetti, Christophe Drouet, Christèle Combes, Christian Rey, Anna Tampieri, et al.. Surface Characteristics of Nanocrystalline Apatites: Effect of Mg Surface Enrichment on Morphology, Surface Hydration Species, and Cationic Environments. Langmuir, 2009, 25 (10), pp.5647-5654. ⟨10.1021/la804230j⟩. ⟨hal-03476679⟩