School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
J Nanosci Nanotechnol. 2019 Jul 1;19(7):3762-3771. doi: 10.1166/jnn.2019.16315.
Nanoparticles (NPs) have been widely studied and shown significant potential in biological and medical applications owing to their unique physicochemical properties. However, aggregation will severely restrict NP use by causing a change in biological effects of related NPs. This study experimentally investigated the aggregation behaviors of AuNPs in deionized (DI) water and whole blood by transmission electron microscopy and dynamic light scattering. The effects of NP size, NP concentration, temperature, and surface modification were analyzed and experimental results were rationalized by the extended Derjaguin-Landau-Verwey-Overbeek theory. The results show the advantage of selecting relatively large NP size and low NP concentration within the applicable range in achieving good dispersion. Higher temperature can enhance NP aggregation both in terms of aggregation rate and in aggregate size. In whole blood, the percentage of the AuNPs over 200 nm increased by more than threefold from 21 °C to 57 °C. Compared with the NP size and concentration, temperature most significantly affected NP aggregation. NP concentration exerts a relatively slighter influence than temperature and NP size when it changes within a relatively narrow range. The degree of NP aggregation in whole blood is higher than that in DI water as the ions and proteins will neutralize the electric charge and decrease the electrostatic force between NPs. Hydrophilic surface modification can effectively inhibit NP aggregation by increasing the electrostatic force, weakening the hydrophobic force, and preventing the Au-protein assembly. However, NP aggregation of hydrophilic polyethylene glycol-modified AuNPs was still observed in whole blood.
纳米粒子（NPs）由于其独特的物理化学性质，在生物和医学应用中得到了广泛的研究，并显示出了巨大的潜力。然而，聚集会严重限制 NP 的使用，因为它会改变相关 NPs 的生物效应。本研究通过透射电子显微镜和动态光散射实验研究了 AuNPs 在去离子（DI）水和全血中的聚集行为。分析了 NP 尺寸、NP 浓度、温度和表面修饰的影响，并通过扩展的 Derjaguin-Landau-Verwey-Overbeek 理论对实验结果进行了合理化解释。结果表明，在适用范围内选择相对较大的 NP 尺寸和较低的 NP 浓度有利于实现良好的分散。较高的温度可以提高 NP 的聚集速率和聚集物的尺寸。在全血中，57°C 时大于 200nm 的 AuNPs 的比例比 21°C 时增加了三倍以上。与 NP 尺寸和浓度相比，温度对 NP 聚集的影响最大。当 NP 浓度在相对较窄的范围内变化时，其影响比温度和 NP 尺寸稍小。全血中的 NP 聚集程度高于 DI 水，因为离子和蛋白质会中和电荷并减少 NP 之间的静电力。亲水性表面修饰可以通过增加静电力、削弱疏水力和防止 Au-蛋白组装来有效抑制 NP 聚集。然而，亲水性聚乙二醇修饰的 AuNPs 在全血中仍观察到 NP 聚集。
