Micro- and nano-tubules built from loosely and tightly rolled up thin sheets.
Micro- and nano-tubules built from loosely and tightly rolled up thin sheets.
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DOI：
10.1039/c5cp06084b
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发表时间：
2016-01
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通讯作者：
Luisa Losensky;Björn Goldenbogen;Gudrun Holland;M. Laue;Anca Petran;J. Liebscher;H. Scheidt;Alexander Vogel;D. Huster;E. Klipp;A. Arbuzova
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作者：
Luisa Losensky;Björn Goldenbogen;Gudrun Holland;M. Laue;Anca Petran;J. Liebscher;H. Scheidt;Alexander Vogel;D. Huster;E. Klipp;A. Arbuzova
由两亲性分子构建的管状结构在纳米传感、药物输送和油的结构方面具有重要意义。在这项研究中，我们表征了在胆固醇核苷结合物、胆固醇氨基尿苷(CholAU)和磷脂酰胆碱(PC)的水悬浮液中建立的小管。在具有与CholAU长度相当的链长的不饱和PC的混合物中，观察到两种不同类型的管状结构：纳米管和微管的平均直径分别在50-300 nm和2-3μm范围内。利用低温扫描电子显微镜(Cryo-SEM)，我们发现纳米管和微管的形态不同：纳米管密集堆积，而微管由松散滚动的波状片层组成。原子力显微镜(AFM)显示，纳米管由4~5 nm厚的富含CholAU的双层膜构成，处于结晶态。固态(2)H-核磁共振波谱也证实，约25%的CholAU形成了刚性晶相，约占CholAU组成小管的部分。我们发现CholAU/PC小管可以通过插入到脂质双层的分子和自发地插入到小管外层的荧光标记的PC和亲脂的核酸来功能化。管状结构可以例如通过DNA杂交物进行负载和交联化，因此具有进一步开发的意义，例如作为组织再生的储存库支架。
Tubular structures built from amphiphilic molecules are of interest for nano-sensing, drug delivery, and structuring of oils. In this study, we characterized the tubules built in aqueous suspensions of a cholesteryl nucleoside conjugate, cholesterylaminouridine (CholAU) and phosphatidylcholines (PCs). In mixtures with unsaturated PCs having chain lengths comparable to the length of CholAU, two different types of tubular structures were observed; nano- and micro-tubules had average diameters in the ranges 50-300 nm and 2-3 μm, respectively. Using cryo scanning electron microscopy (cryo-SEM) we found that nano- and micro-tubules differed in their morphology: the nano-tubules were densely packed, whereas micro-tubules consisted of loosely rolled undulated lamellas. Atomic force microscopy (AFM) revealed that the nano-tubules were built from 4 to 5 nm thick CholAU-rich bilayers, which were in the crystalline state. Solid-state (2)H NMR spectroscopy also confirmed that about 25% of the total CholAU, being about the fraction of CholAU composing the tubules, formed the rigid crystalline phase. We found that CholAU/PC tubules can be functionalized by molecules inserted into lipid bilayers and fluorescently labeled PCs and lipophilic nucleic acids inserted spontaneously into the outer layer of the tubules. The tubular structures could be loaded and cross-linked, e.g. by DNA hybrids, and, therefore, are of interest for further development, e.g. as a depot scaffold for tissue regeneration.