武汉大学邓鹤翔团队报道了用于核酸提取的金属有机框架中的非常大的3D笼。相关研究成果于2023年5月24日发表在《美国化学会杂志》。

在生物应用中，由分子构建块组装的中孔区（2–50 nm）三维（3D）笼是非常理想的；然而，它们的晶体形式的合成以及它们的结构表征是相当具有挑战性的。

该文中，研究人员报道了MOF晶体中超大3D笼的合成，MOF-929中的内部笼尺寸分别为6.9和8.5nm；在立方晶胞中，MOF-939中的a分别为17.4和22.8nm。这些笼由长度为0.85和1.3nm的相对较短的有机连接体构建，其中分子运动的影响被最小化，从而有利于它们的结晶。0.45nm的连接体长度延伸导致笼尺寸最大增加2.9nm，从而在笼膨胀中提供最高效率。通过X射线衍射和透射电子显微镜对这些3D笼的空间排列进行可视化。在晶体中获得这些笼的工作推动了由分子构建3D笼的尺寸边界，也利用了每个化学键可能支持的空间面积的极限，发现笼的膨胀效率起着关键作用。MOFs中这些超大的3D笼可用于从水溶液中完全提取长核酸，如总RNA和质粒。

附：英文原文

Title: Extremely Large 3D Cages in Metal–Organic Frameworks for Nucleic Acid Extraction

Author: Gaoli Hu, Qi Liu, Yi Zhou, Wei Yan, Yuqing Sun, Shuang Peng, Chengbin Zhao, Xiang Zhou, Hexiang Deng

Issue&Volume: May 24, 2023

Abstract: Three-dimensional (3D) cages in the mesopore regime (2–50 nm) assembled from molecular building blocks are highly desirable in biological applications; however, their synthesis in crystalline form is quite challenging, as well as their structure characterization. Here, we report the synthesis of extremely large 3D cages in MOF crystals, with internal cage sizes of 6.9, and 8.5 nm in MOF-929; 9.3 and 11.4 nm in MOF-939, in cubic unit cells, a = 17.4 and 22.8 nm, respectively. These cages are constructed from relatively short organic linkers with the lengths of 0.85 and 1.3 nm, where the influence from molecular motion is minimized, thus favoring their crystallization. A 0.45 nm linker length elongation leads to a maximum 2.9 nm increase in cage size, giving a supreme efficiency in cage expansion. The spatial arrangements of these 3D cages were visualized by both X-ray diffraction and transmission electron microscopy. The efforts to obtain these cages in crystals pushed forward the size boundary for the construction of 3D cages from molecules and also exploited the limit of the area in space possibly supported per chemical bond, where the expansion efficiencies of the cages were found to play a critical role. These extremely large 3D cages in MOFs were useful in the complete extraction of long nucleic acid, such as total RNA and plasmid from aqueous solution.

DOI: 10.1021/jacs.3c02128

Source: https://pubs.acs.org/doi/10.1021/jacs.3c02128