Gasquères G, Bonhomme C, Maquet J, Babonneau F, Hayakawa S, Kanaya T, Osaka A
Université Pierre et Marie Curie-Paris6, UMR 7574 CNRS, Laboratoire de Chimie de la Matière Condensée de Paris, Paris, F-75005, France.
Magn Reson Chem. 2008 Apr;46(4):342-6. doi: 10.1002/mrc.2109.
Silicon-substituted hydroxyapatite (Si-HAp) has shown promising properties such as high-bone remodeling around implants. So far, the techniques used for the structural characterization of the Si-HAp have given indirect evidence of the presence of silicon inside the structure (by X-ray and neutron diffraction). In this paper, we focus on Si-HAp derivatives obtained by a precipitation method (widely described in the literature). We demonstrate here by solid-state NMR spectroscopy that only a fraction of the silicon atoms are incorporated into the HAp lattice in the form of Q(0) (SiO(4) (4-)) species, for 4.6 wt% Si-HAp. A large amount of silicate units are located outside the HAp structure and correspond to silica-gel units. All results were established through (29)Si MAS, (1)H -->(29)Si CP MAS and T(1)rho((1)H) edited (1)H -->(29)Si CP MAS experiments. This last pulse scheme acted as a powerful editing sequence, leading to unambiguous spectroscopic conclusions, concerning the location of the SiO(4) (4-) moieties.
硅取代羟基磷灰石（Si-HAp）已展现出如在植入物周围具有高骨重塑等有前景的特性。到目前为止，用于Si-HAp结构表征的技术已给出结构内部存在硅的间接证据（通过X射线和中子衍射）。在本文中，我们聚焦于通过沉淀法获得的Si-HAp衍生物（文献中有广泛描述）。我们在此通过固态核磁共振光谱证明，对于4.6 wt%的Si-HAp，只有一部分硅原子以Q(0)（SiO₄⁴⁻）物种的形式掺入到HAp晶格中。大量的硅酸盐单元位于HAp结构之外，对应于硅胶单元。所有结果均通过²⁹Si MAS、¹H→²⁹Si CP MAS和T₁ρ(¹H)编辑的¹H→²⁹Si CP MAS实验得出。最后这种脉冲序列起到了强大的编辑序列作用，得出了关于SiO₄⁴⁻部分位置的明确光谱结论。
