Determination of nanostructures and drug distribution in lipid nanoparticles by single molecule microscopy
Determination of nanostructures and drug distribution in lipid nanoparticles by single molecule microscopy
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DOI：
10.1016/j.ejpb.2016.10.020
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发表时间：
2017-01-01
影响因子：
4.9
通讯作者：
Alexiev, Ulrike
中科院分区：
文献类型：
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作者：
Boreham, Alexander;Volz, Pierre;Alexiev, Ulrike
纳米结构脂质载体（NLC）的载药能力取决于脂质基质内纳米结构的形成。然而，这些纳米结构的尺寸低于可见光的衍射极限的调查是相当具有挑战性的。因此，到目前为止，不可能确定NLC内的结构和药物分布。因此，我们的目标是开发一种方法来可视化的脂质载体内的纳米结构。模型NLC加载亲脂性的荧光药物模拟物，ATTO-Oxa 12，产生和单分子跟踪和定位的超分辨显微镜研究。结果显示，填充ATTO-Oxa 12的球形纳米结构的直径类似于70 nm和120-130 nm，均小于NLC尺寸（类似于160 nm）。ATTO-Oxa 12扩散常数由单分子迹线计算（D >= 1 μ m（2）/s），并表示模型药物在油性组分中的分布。这些数据一起表明存在载药的油性纳米隔室，其可以填充高达模型NLC体积的50%。总之，现在可以使用基于单分子显微镜的新工具，该工具可以精确测定药物分布和脂质纳米结构的表征，这些信息对于优化脂质纳米颗粒制剂至关重要。(C)© 2016 Elsevier B. V.版权所有。
Drug loading capacity in nanostructured lipid carriers (NLC) depends on the formation of nanostructures within the lipid matrix. However, investigation of these nanostructures with sizes below the diffraction limit of visible light is quite challenging. Thus, until now the determination of structures and drug distribution within NLCs was not possible. Therefore, we aimed at developing a method to visualize the nanostructures within the lipid carriers. Model NLCs loaded with a lipophilic fluorescent drug mimetic, ATTO-Oxa12, were produced and investigated by single-molecule tracking and localization based superresolution microscopy. Results revealed spherical ATTO-Oxa12-filled nanostructures with diameters of similar to 70 nm and 120-130 nm, both smaller than the NLC size (similar to 160 nm). The ATTO-Oxa12 diffusion constant was calculated from the single-molecule traces (D >= 1 mu m(2)/s) and indicated the distribution of the model drug in the oily component. Together these data suggest the existence of drug-loaded oily nanocompartments, which could fill up to similar to 50% of the model NLCs' volume. In conclusion, a novel tool based on single-molecule microscopy is now available that allows for the precise determination of drug distribution and the characterization of lipid nanostructures, information that is paramount for optimizing lipid nanoparticle formulations. (C) 2016 Elsevier B.V. All rights reserved.