The use of dual beam ESEM FIB to reveal the internal ultrastructure of hydroxyapatite nanoparticle-sugar-glass composites.
The use of dual beam ESEM FIB to reveal the internal ultrastructure of hydroxyapatite nanoparticle-sugar-glass composites.
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使用双束 ESEM FIB 揭示羟基磷灰石纳米颗粒-糖玻璃复合材料的内部超微结构。
DOI：
10.1007/s10856-008-3539-6
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Wright DM
中科院分区：
文献类型：
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作者：
Wright DM
目前正在开发从羟基磷灰石(HA)纳米颗粒(NP)糖悬浮液喷雾干燥的微粒(MP)作为一种长期释放的疫苗载体。含有大量糖分的那些不能用超微切割法切开，因为树脂被糖排除在外。聚焦离子束(FIB)球磨是制备MPS薄片的唯一方法，可以用透射电子显微镜(TEM)观察MPS的超微结构。已经探索了几种方法，我们发现最简单的方法是将MPS包裹在银DAG中，夹在金箔之间进行FIB球磨，使多个MPS能够同时切片。含有80%糖的喷雾干燥MPS具有与NP尺寸相当的纳米粒子间分离(~50 nm)。用50%糖或不加糖喷雾干燥的MPS包装更紧密。纳米颗粒之间存在10 nm量级的纳米孔隙率。在无糖条件下喷雾干燥和超微切割法或FIB-研磨法切片的MPS具有相似的纳米级形貌。选区电子衍射(SAED)表明，经过FIB球磨后的HA仍保持(基本上)结晶状态。
Microparticles (MP) spray dried from hydroxyapatite (HA) nanoparticle (NP) sugar suspensions are currently under development as a prolonged release vaccine vehicle. Those with a significant sugar component cannot be sectioned by ultramicrotomy as resins are excluded by the sugar. Focused ion beam (FIB) milling is the only method to prepare thin sections that enables the inspection of the MPs ultrastructure by transmission electron microscopy (TEM). Several methods have been explored and we have found it is simplest to encapsulate MPs in silver dag, sandwiched between gold foils for FIB-milling to enable multiple MPs to be sectioned simultaneously. Spray dried MPs containing 80% sugar have an inter-nanoparticle separation that is comparable with NP size (~50 nm). MPs spray dried with 50% sugar or no sugar are more tightly packed. Nano-porosity in the order of 10 nm exists between NPs. MPs spray dried in the absence of sugar and sectioned by ultramicrotomy or by FIB-milling have comparable nanoscale morphologies. Selected area electron diffraction (SAED) demonstrates that the HA remains (substantially) crystalline following FIB-milling.