Biomimetic Apatite Mineralization Mechanisms of Mesoporous Bioactive Glasses as Probed by Multinuclear 31P, 29Si, 23Na and 13C Solid-State NMR
Biomimetic Apatite Mineralization Mechanisms of Mesoporous Bioactive Glasses as Probed by Multinuclear 31P, 29Si, 23Na and 13C Solid-State NMR
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DOI：
10.1021/jp105408c
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发表时间：
2010-11-18
影响因子：
3.7
通讯作者：
Eden, Mattias
中科院分区：
文献类型：
--
作者：
Gunawidjaja, Philips N.;Lo, Andy Y. H.;Eden, Mattias
采用幻角旋转(MAS)核磁共振(核磁共振)实验研究了Ca0.10Si0.85P0.04O1.90介孔生物活性玻璃在模拟体液(SBF)中不同时间间隔下的表面反应。采用粉末X射线衍射法和P-31核磁共振技术，定量监测了磷酸钙表面无定形的形成和随后结晶成羟基碳酸盐磷灰石(HCA)的过程。在HCA形成之前，H-1->；Si-29交叉极化(CP)核磁共振表明钙离子溶解；在SBF暴露一周后，观察到MBG表面硅酸盐离子形态的连接性略有增加。分别用H-1->；C-13 CPMAS和Na-23核磁共振研究了碳酸盐和钠离子在生物活性正磷酸盐表层的结合情况。我们讨论了与MBGS相比，为传统熔融制备的生物玻璃建立的组成-生物活性关系的相似性和差异性。含磷MBG的高生物活性是由于MBG孔壁上存在无定形的正磷酸钙团簇而加速了其表面反应。
An array of magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy experiments is applied to explore the surface reactions of a mesoporous bioactive glass (MBG) of composition Ca0.10Si0.85P0.04O1,90 when subjected to a simulated body fluid (SBF) for variable intervals. Powder X-ray diffraction and P-31 NMR techniques are employed to quantitatively monitor the formation of an initially amorphous calcium phosphate surface layer and its subsequent crystallization into hydroxycarbonate apatite (HCA). Prior to the onset of HCA formation, H-1 -> Si-29 cross-polarization (CP) NMR evidence dissolution of calcium ions; a slightly increased connectivity of the speciation of silicate ions is observed at the MBG surface over 1 week of SBF exposure. The incorporation of carbonate and sodium ions into the bioactive orthophosphate surface layer is explored by H-1 -> C-13 CPMAS and Na-23 NMR, respectively. We discuss similarities and distinctions in composition-bioactivity relationships established for traditional melt-prepared bioglasses compared to MBGs. The high bioactivity of phosphorus-bearing MBGs is rationalized to stem from an acceleration of their surface reactions due to presence of amorphous calcium orthophosphate clusters of the MBG pore wall.