Bioactive glass sol-gel foam scaffolds: Evolution of nanoporosity during processing and in situ monitoring of apatite layer formation using small- and wide-angle X-ray scattering.
Bioactive glass sol-gel foam scaffolds: Evolution of nanoporosity during processing and in situ monitoring of apatite layer formation using small- and wide-angle X-ray scattering.
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DOI：
10.1002/jbm.a.32206
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发表时间：
2009-10
期刊：
影响因子：
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通讯作者：
V. Fitzgerald;Richard P. Martin;Julian R. Jones;Dong Qiu;K. Wetherall;Robert M. Moss;R. J. Newport
中科院分区：
文献类型：
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作者：
V. Fitzgerald;Richard P. Martin;Julian R. Jones;Dong Qiu;K. Wetherall;Robert M. Moss;R. J. Newport
最近的工作突出了溶胶-凝胶衍生的硅酸钙玻璃用于再生或替换受损骨组织的潜力。本文提出的工作提供了新的见解生物活性钙硅溶胶-凝胶泡沫的处理，以及与它们相关的反应机制时，在体外浸泡在模拟体液（SBF）。小角X-射线散射和广角X-射线散射（衍射）已被用来研究这些泡沫通过热处理的稳定性，与类似的原位时间分辨的数据被收集的泡沫浸泡在SBF。在热加工过程中，已经确定孔径在16.5-62.0 nm的范围内，并且仅在泡沫被加热到400 ℃及以上时才存在。在泡沫加热至600 ℃之前，存在硝酸钙微晶;微晶尺寸从75 nm变化至145 nm，并且随着热处理至300 ℃而尺寸增加，然后在400 ℃下尺寸减小至95 nm。原位时间分辨的数据表明，平均孔径作为在SBF中的浸泡时间的函数而减小，因为磷酸钙在玻璃表面上生长。在相同的时间内，布拉格峰指示磷酸三钙是明显的后，只有1小时的浸泡时间，后来，也看到了羟基碳酸磷灰石。羟基碳酸盐磷灰石似乎在（h，k，0）方向上具有优选取向。
Recent work has highlighted the potential of sol-gel-derived calcium silicate glasses for the regeneration or replacement of damaged bone tissue. The work presented herein provides new insight into the processing of bioactive calcia-silica sol-gel foams, and the reaction mechanisms associated with them when immersed in vitro in a simulated body fluid (SBF). Small-angle X-ray scattering and wide-angle X-ray scattering (diffraction) have been used to study the stabilization of these foams via heat treatment, with analogous in situ time-resolved data being gathered for a foam immersed in SBF. During thermal processing, pore sizes have been identified in the range of 16.5-62.0 nm and are only present once foams have been heated to 400 degrees C and above. Calcium nitrate crystallites were present until foams were heated to 600 degrees C; the crystallite size varied from 75 to 145 nm and increased in size with heat treatment up to 300 degrees C, then decreased in size down to 95 nm at 400 degrees C. The in situ time-resolved data show that the average pore diameter decreases as a function of immersion time in SBF, as calcium phosphates grow on the glass surfaces. Over the same time, Bragg peaks indicative of tricalcium phosphate were evident after only 1-h immersion time, and later, hydroxycarbonate apatite was also seen. The hydroxycarbonate apatite appears to have preferred orientation in the (h,k,0) direction.