单颗粒透射电子显微重构在纳米颗粒结构分析中的应用

doi:10.16553/j.cnki.issn1000-985x.2026.0043

摘要/Abstract

摘要： 冷冻电子断层（Cryo-ET）成像能够原位解析结构异质性的柔性生物大分子的天然结构。然而，传统断层成像存在大尺寸图像偏移、倾斜误差等问题，易导致重构失真。单颗粒电子断层扫描（IPET）重构方法通过对单个独立颗粒的局域区域逐次迭代对齐，可以显著提升重构的精度与可靠性。针对传统电子显微表征难以准确揭示柔性、结构异质性纳米材料三维构型的问题，本文将Cryo-ET和IPET方法应用于纳米材料的结构分析，可实现纳米材料原位、自然状况下的三维表征，全面获取其形貌、内部通道、界面作用等关键信息。例如：金纳米笼的微观结构清晰表征了其壳层结构特征，明确了壳层上通道路径的分布规律；石墨烯插入磷脂囊泡的复合体结构直观验证了石墨烯的穿膜特性，展示了两者的结合位点；对纳米纤维的结构表征解析了其多级螺旋结构，揭示出其自组装的机制。研究表明，Cryo-ET和IPET方法在柔性纳米材料的三维结构表征中具有独特优势，可为纳米材料结构-性能关系研究及相关功能设计提供新的表征手段。凭借原位、高分辨、适配结构异质体系等优势，该方法在结构生物学与纳米材料科学中具有广阔应用前景，可为疾病机制阐释、新药研发及纳米材料设计等提供重要技术支撑。

关键词: 冷冻电子断层成像; 三维重构; 单颗粒电子断层扫描; 纳米材料; 结构解析

Abstract: Cryo-electron tomography （Cryo-ET） enables in situ structural elucidation of flexible biomacromolecules with structural heterogeneity under near-native conditions. However， conventional tomography suffers from issues such as large-scale image shifts and tilting errors， which often lead to reconstruction artifacts. The individual-particle electron tomography （IPET） method achieves significantly improved reconstruction accuracy and reliability by performing iterative alignment on local regions of individual particles. To address the limitation of conventional electron microscopy in accurately resolving the three-dimensional configurations of flexible and structurally heterogeneous nanomaterials， Cryo-ET combined with IPET was employed for structural characterization of nanomaterials in this study. This approach enables in situ three-dimensional characterization under near-native conditions and facilitates comprehensive acquisition of key structural information， including morphology， internal channels， and interfacial interactions. For example， the microstructure of gold nanocages clearly reveals their shell architecture and characterizes the distribution pattern of channel pathways within the shell. The three-dimensional structure of graphene-phospholipid vesicle complexes offers structural insight into the interaction between graphene and the membrane， revealing their binding sites. Structural analysis of nanofibers resolves their multilevel helical architecture and provides structural insight into their self-assembly behavior. The results demonstrate that the combination of Cryo-ET and IPET offers unique advantages for the three-dimensional structural characterization of flexible nanomaterials， and provides a new characterization approach for investigating structure-property relationships and guiding related functional design of nanomaterials. With the advantages of in situ characterization， high resolution， and adaptability to structurally heterogeneous systems， this approach shows broad potential in structural biology and nanomaterials science and may provide important technical support for elucidating disease mechanisms， new drug development， and nanomaterial design.

Key words: cryo-electron tomography; three-dimensional reconstruction; individual particle electron tomography; nanomaterial; structural analysis

中图分类号:

TB383

翟啸波, 黄雪丽, 曾渝, 杨柳静, 解忧. 单颗粒透射电子显微重构在纳米颗粒结构分析中的应用[J]. 人工晶体学报, 2026, 55(8): 1313-1320.

ZHAI Xiaobo, HUANG Xueli, ZENG Yu, YANG Liujing, XIE You. Application of Individual Particle Transmission Electron Microscopy Reconstruction in Nanoparticle Structural Analysis[J]. Journal of Synthetic Crystals, 2026, 55(8): 1313-1320.

图/表 4

图1 IPET法解构磷脂囊泡的三维结构。（a）磷脂囊泡不同倾角的冷冻电子显微镜透射图像；（b）针对目标颗粒不同倾角下局域透射图像的选取；（c）经过局域断层迭代算法重构的3D密度图（已进行楔块缺失校正）

Fig.1 3D construction of phospholipid vesicles by IPET. （a） Cryo-transmission electron microscopy （Cryo-TEM） images of phospholipid vesicles at different tilt angles；（b） selection of local projections of the target particle at different tilt angles；（c） 3D density map reconstructed by the local tomographic iterative algorithm （with missing-wedge correction applied）

图2 干样品金纳米笼不同倾角下的透射图像（a）和相应角度的3D密度图（b）；（c）切面图，箭头指示通道位置。空间分辨率为15 ?

Fig.2 Transmission images of dried gold nanocages at different tilt angles （a） and the corresponding 3D density maps at the same angles （b）；（c） slice view， with arrows indicating the channel positions. The spatial resolution is 15 ?

图3 磷脂膜和石墨烯混合培养样品在冷冻电子显微镜不同倾角下的透射图像（a）和相应角度的3D密度图（b），箭头指示石墨烯的位置。空间分辨率为78 ?

Fig.3 Transmission images of phospholipid membranes co-cultured with graphene at different tilt angles （a） and the corresponding 3D density maps at the same angles （b）， the arrow indicates the position of graphene. The spatial resolution is 78 ?

图4 自组装纳米纤维样品在冷冻电子显微镜不同倾角下的透射图像（a）和相应角度的3D密度图（b）。空间分辨率为64 ?

Fig.4 Transmission images of self-assembled nanofiber samples at different tilt angles （a） and the corresponding 3D density maps at the same angles （b）. The spatial resolution is 64 ?

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