Zhao Y F, Loo S C J, Ma J
Deakin Institute of Biotechnology, Deakin University, Geelong, Victoria 3217, Australia.
J Nanosci Nanotechnol. 2009 Jun;9(6):3720-7. doi: 10.1166/jnn.2009.ns57.
In this work, mesoporous hydroxyapatite-silica (HA-silica) composite materials with four different Si:Ca:P ratios were sol-gel derived through self-assembly using triblock copolymer Pluronics P123 as template. The composition and mesoporous structure formed were characterized by X-ray diffraction and electron microscopy. The XRD patterns indicated that the intensity of the HA phase becomes stronger as the Ca/Si ratio of the composite increases. From nitrogen gas analysis at 77 K, type IV isotherm plots for typical mesoporous materials were observed for all of the samples. However, the mesoporous structure of HA-silica tends to becomes less ordered as the Ca/Si ratio increases. Promising consistency between the pore sizes from the Barrett, Joyner and Halenda (BJH) method, Transmission Electron Microscopy (TEM) and Small Angle X-ray diffraction (SAXRD) was also observed. The formation mechanism of mesoporous HA-silica composites was proposed, where the interaction between the crystallization of HA and the surfactant liquid crystal determines the regularity of the meso-structure. In vitro drug loading and release studies showed that drug loading capacity is dependent on the pore volume of the sample, and the mesoporosity of the samples were responsible for the sustained release of drugs. In vitro cell culture of the samples showed promising biocompatibility where osteosarcoma cells were observed to grow favourably on the synthesized composites.
在本研究中，以三嵌段共聚物Pluronic P123为模板，通过自组装溶胶-凝胶法制备了具有四种不同Si:Ca:P比的介孔羟基磷灰石-二氧化硅（HA-二氧化硅）复合材料。采用X射线衍射和电子显微镜对所形成的组成和介孔结构进行了表征。XRD图谱表明，随着复合材料中Ca/Si比的增加，HA相的强度增强。通过77K下的氮气分析，所有样品均观察到典型介孔材料的IV型等温线图。然而，随着Ca/Si比的增加，HA-二氧化硅的介孔结构有序度趋于降低。同时还观察到，采用巴雷特、乔伊纳和哈伦达（BJH）方法、透射电子显微镜（TEM）和小角X射线衍射（SAXRD）测得的孔径之间具有良好的一致性。提出了介孔HA-二氧化硅复合材料的形成机制，即HA的结晶与表面活性剂液晶之间的相互作用决定了介观结构的规整性。体外药物负载和释放研究表明，药物负载能力取决于样品的孔体积，样品的介孔率是药物缓释的原因。样品的体外细胞培养显示出良好的生物相容性，观察到骨肉瘤细胞在合成的复合材料上生长良好。
