Oligosaccharide-Mediated Nuclear Transport of Nanoparticles
Oligosaccharide-Mediated Nuclear Transport of Nanoparticles
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DOI：
10.1002/cbic.200800464
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发表时间：
2008-11-03
期刊：
影响因子：
3.2
通讯作者：
Ijiro, Kuniharu
中科院分区：
文献类型：
--
作者：
Niikura, Kenichi;Sekiguchi, Shota;Ijiro, Kuniharu
纳米颗粒进入细胞核的运输是一项潜在的重要技术，因为它可以为广泛的应用开辟道路，包括基因组DNA的序列特异性检测，有效的DNA转染，以及药物进入细胞核的特异性据报道，大于40kd的蛋白质不通过被动扩散进入细胞核同样，大分子或粒子的核进口也受到严格管制。因此，含有金纳米粒子和量子点的纳米粒子的核导入是通过在表面涂覆经典的核定位信号（NLS）来实现的，即短而高正电荷的肽然而，问题仍然存在，带正电的粒子可以与血清蛋白相互作用，导致血浆室的快速清除由于带阳离子的NLS与带负电荷的DNA相互作用，NLS肽不能作为DNA进入细胞核的有效信号；[5]这意味着当使用dna显示纳米粒子时，基于肽的阳离子NLS的使用可能受到限制。Monsigny等人已经证明糖也可以作为核定位信号。[6-9]新的糖蛋白，BSA（牛血清白蛋白）-葡萄糖，BSA -甘露糖和BSA -聚焦蛋白可以迅速运输到HeLa细胞的细胞核中，而没有化学修饰的BSA则不能。由于碳水化合物通常具有较高的生物相容性和水溶性，因此它们适合用于合成载体和纳米颗粒的改性。然而，在此之前，只研究了这些碳水化合物信号在蛋白质核输入中的应用，并且没有关于碳水化合物信号在人工材料（如纳米颗粒和聚合物）核输入中的有效性的报道。以前使用牛血清白蛋白的报道只关注单糖作为信号。在本文中，我们将碳水化合物的种类从单糖扩展到低聚糖，以寻找适用于纳米颗粒核进口的有效信号。在此，我们提出了我们独特的发现，纳米粒子（量子点）表面显示低聚α-葡萄糖吡喃苷很容易被运输到洋地黄苷渗透HeLa细胞的细胞核中。半导体量子点的直径为几纳米，通过在其表面显示多个配体，可以很容易地实现其在细胞内的特定运输。据我们所知，这是第一篇描述纳米颗粒在不使用阳离子NLS的情况下进入细胞核的报道。由于被α-葡萄糖苷取代的牛血清白蛋白被有效地转运到细胞核中，因此我们合成了含有由不同数量葡萄糖单位组成的各种碳水化合物的新糖脂（方案1）。除了α-单葡萄糖苷脂质3外，我们还合成了麦芽糖(Glcα1-4Glc) -脂质4、麦芽糖(Glcα1-4Glcα1- 4glc) -脂质5和葡萄糖(Glcα1-6Glcα1-4Glc) -脂质6。纤维素三糖(Glcβ1-4Glcβ1-4Glc) -脂质7是一种仅由β-连接葡萄糖组成的三糖，因此脂质7被用作α-连接葡萄糖的对照。根据先前描述的方法[10,11]，从完全乙酰化的碳水化合物、己糖（乙二醇）和11-溴癸烯开始合成新糖脂。按照Yang等人的描述，在水中制备了巯基丙酸（MPA）稳定的CdTe纳米晶体。[12]通过MPA与水中新糖脂的表面交换合成了显示糖的CdTe量子点（图1A），然后…
The transport of nanoparticles into the cellular nucleus is a potentially important technique because it can open the way to a wide range of applications, including the sequence-specific detection of genomic DNA, efficient DNA transfection, and the specific entry of drugs into the nucleus.[1] It has been reported that the nuclear import of proteins larger than 40 kD does not occur by passive diffusion.[2] Similarly, the nuclear import of macromolecules or particles is strictly regulated. Therefore, the nuclear import of nanoparticles that contain gold nanoparticles and quantum dots has been achieved by coating the surface with classical nuclear localization signals (NLS), that is, short, highly positively charged peptides.[3] However, the problem remains that positively charged particles can interact with serum protein, resulting in rapid clearance from the plasma compartment.[4] Because the cationic NLS interacts with negatively charged DNA, NLS peptides do not work as efficient signals for transport of DNA into the nucleus;[5] this implies that the use of peptide-based cationic NLS might be limited when using DNA-displaying nanoparticles. Monsigny et al. have shown that sugars can also work as nuclear localization signals.[6–9] The neoglycoproteins, BSA (bovine serum albumin)–glucose, BSA–mannose and BSA–fucose are rapidly transported into the nucleus of HeLa cells, whereas BSA without chemical modifications is not. Because carbohydrates normally show high biocompatibility and water solubility, they are suitable for use in the modification of synthetic carriers and nanoparticles. Previously, however, only the application of these carbohydrate signals to the nuclear import of proteins was examined, and there are no reports on the effectiveness of carbohydrate signals for the nuclear import of artificial materials, such as nanoparticles and polymers. Previous reports that used BSA have focused only on monosaccharides as a signal. In this paper, we expand the varieties of carbohydrates tested from monosaccharides to oligosaccharides in the search for an efficient signal that is applicable to the nuclear import of nanoparticles. Herein, we present our unique finding that nanoparticles (quantum dots) that display oligo α-glucopyranoside on their surface are readily transported into the nucleus of digitonin-permeabilized HeLa cells. Semiconductor QDs have a diameter of several nanometers and their specific transport inside the cell can be readily achieved through the display of multiple ligands on their surface. As far as we know, this is the first report to describe the import of nanoparticles into the nucleus without the use of cationic NLS. Because BSA that has been substituted with α-glucopyranoside has been reported to be efficiently transported into the cell nucleus,[6] we synthesized neoglycolipids that contain various carbohydrates comprised of different numbers of glucose units (Scheme 1). In addition to α-monoglucopyranoside–lipid 3, we synthesized maltose (Glcα1-4Glc)–lipid 4, maltotriose (Glcα1-4Glcα1-4Glc)–lipid 5, and panose (Glcα1-6Glcα1-4Glc)–lipid 6. The cellotriose (Glcβ1-4Glcβ1-4Glc)–lipid 7 is a trisaccharide that is composed of only a β-linked glucose, thus lipid 7 was used as a control to α-linked glucose. Neoglycolipids were synthesized based on a previously described method [10, 11] by starting from fully acetylated carbohydrates, hexa (ethyleneglycol) and 11-bromoundecene.CdTe nanocrystals that had been stabilized with mercaptopropionic acid (MPA) were prepared in water as described by Yang et al.[12] Sugar-displaying CdTe QDs were synthesized by surface exchange from MPA to the neoglycolipid in water (Figure 1A), and then …