pH-Dependent Synthesis and Stability of Aqueous, Elemental Bismuth Glyconanoparticle Colloids: Potentially Biocompatible X-ray Contrast Agents
pH-Dependent Synthesis and Stability of Aqueous, Elemental Bismuth Glyconanoparticle Colloids: Potentially Biocompatible X-ray Contrast Agents
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DOI：
10.1021/cm300083j
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发表时间：
2012-05-08
影响因子：
8.6
通讯作者：
Goforth, Andrea M.
中科院分区：
文献类型：
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作者：
Brown, Anna L.;Goforth, Andrea M.
利用 pH 依赖性溶解度平衡，我们开发了化学和胶体稳定的铋 (0) 糖纳米颗粒的水合成方法。该合成方法可产生具有潜在生物相容性的元素铋纳米粒子 (BiNP)，并涉及在 pH 控制溶液中通过硼氢化钠还原水性铋 (III) 阳离子。研究发现，医用级右旋糖酐（75 000 MW）除了可以促进胶体稳定性和单个纳米晶体的分离之外，还可以保护纳米晶体免受氧化。颗粒形成的速率取决于合成 pH 值，通过增加 pH 值来降低反应速率，产生更多数量的单独和分离的 Bi(0) 纳米晶体。葡聚糖包被的 BiNPs 的稳定水胶体在长时间光照下分解，并且 NPs 溶解在酸性溶液 (pH 12) 中，但在磷酸盐缓冲盐溶液 (pH 7.4) 和水中稳定。 pH 8 至 10 之间的其他水溶液。基于铋的纳米材料先前已被证明是长循环 X 射线造影剂，我们预计这些高原子序数铋 (0) 糖纳米粒子将在类似的应用中得到使用。
Taking advantage of a pH-dependent solubility equilibrium, we have developed an aqueous synthesis of chemically and colloidally stable bismuth(0) glyconanoparticles. The synthetic method results in potentially biocompatible elemental bismuth nanoparticles (BiNPs) and involves the reduction of aqueous bismuth(III) cations by sodium borohydride in a pH-controlled solution. Medical-grade dextran (75 000 MW) was found to protect the nanocrystals from oxidation, in addition to promoting colloidal stability and separation of individual nanocrystallites. The rate of particle formation was dependent on synthesis pH, and decreasing the reaction rate by increasing the pH produced a greater number of individual and isolated Bi(0) nanocrystals, Stable, aqueous colloids of the dextran-coated BiNPs decomposed under prolonged light exposure, and the NPs dissolved both in acidic solutions (pH 12), but were stable in phosphate buffered saline solution (pH 7.4) and in other aqueous solutions between pH 8 and 10. Bismuth-based nanomaterials have previously been demonstrated to be long-circulating X-ray contrast agents, and we anticipate that these high-atomic-number bismuth(0) glyconanoparticles will find use in similar applications.