Synthesis of block wise alkylated tetrasaccharide-quantum dot complexes and their utilization for live cell labeling with low cytotoxicity
Synthesis of block wise alkylated tetrasaccharide-quantum dot complexes and their utilization for live cell labeling with low cytotoxicity
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分段烷基化四糖-量子点复合物的合成及其在低细胞毒性活细胞标记中的应用
DOI：
10.1007/s10570-011-9619-7
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发表时间：
2012
期刊：
影响因子：
5.7
通讯作者：
Y. Tanaka.
中科院分区：
文献类型：
--
作者：
Kamitakahara H.;K. Murata-Hirai;Y. Tanaka.
生物成像是理解免疫反应、细胞分化和发育的关键。与单克隆抗体和其他生物分子缀合的量子点（QD）目前用于流式细胞术和免疫组织化学，但是当细胞表面标记物不可用时，单克隆抗体-QD复合物的用途有限。在这项研究中，我们合成了新型的两亲性嵌段烷基化四糖，并开发了一种简单的方法，用于标记各种各样的活细胞与这些碳水化合物封装的有机量子点。新的两亲性嵌段烷基化四糖如下：甲基β-d-吡喃葡萄糖基-（1 → 4）-β-d-吡喃葡萄糖基-（1 → 4）-2，3，6-三-O-甲基-β-d-吡喃葡萄糖基-（1 → 4）-2，3，6-三-O-甲基-d-吡喃葡萄糖苷（1），甲基β-d-吡喃半乳糖基-（1 → 4）-β-d-吡喃葡萄糖基-（1 → 4）-2，3，6-三-O-甲基-β-d-吡喃葡萄糖基-（1 → 4）-2，3，6-三-O-甲基-d-吡喃葡萄糖苷（2），乙基β-d-吡喃葡萄糖基-（1 → 4）-β-d-吡喃葡萄糖基-（1 → 4）-2，3，6-三-O-乙基-β-d-吡喃葡萄糖基-（1 → 4）-2，3，6-三-O-乙基-d-吡喃葡萄糖苷（3），乙基β-D-吡喃半乳糖基-（1 → 4）-β-D-吡喃葡萄糖基-（1 → 4）-2，3，6-三-O-乙基-β-D-吡喃葡萄糖基-（1 → 4）-2，3，6-三-O-乙基-D-吡喃葡萄糖苷（4）。新合成的嵌段烷基化四糖自发组装成胶束状颗粒，其中嵌段烷基化四糖的疏水基团起着重要作用。它们对人体细胞的毒性低于辛基β-d-吡喃葡萄糖苷，一种常用的两亲性葡萄糖苷。流式细胞术和共聚焦激光扫描显微镜显示，嵌段烷基化四氢呋喃-有机QD复合物稳定地附着于活细胞。化合物1和2对活细胞表面的亲和力略高于化合物3和4。由于这些碳水化合物-QD复合物的制备简单，不需要复杂的设备，并且由于复合物可以自主地附着到广谱的细胞系上，因此它们可以用作生物医学研究中的细胞标记试剂。
Bioimaging is a key to understanding immune responses, cell differentiation, and development. Quantum dots (QDs) conjugated with monoclonal antibodies and other biomolecules are currently utilized for flow cytometry and immunohistochemistry, but monoclonal antibody–QD complexes are of limited use when cell surface markers are not available. In this study, we synthesized novel amphiphilic blockwise alkylated tetrasaccharides and developed a simple method for labeling a wide variety of live cells with organic QDs encapsulated with these carbohydrates. The novel amphiphilic blockwise alkylated tetrasaccharides were as follows: methyl β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-d-glucopyranoside (1), methyl β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-d-glucopyranoside (2), ethyl β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-ethyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-ethyl-d-glucopyranoside, (3), and ethyl β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-ethyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-ethyl-d-glucopyranoside (4). The newly synthesized blockwise alkylated tetrasaccharides spontaneously assembled into micelle-like particles, in which the hydrophobic moiety of the blockwise alkylated tetrasaccharides played an important role. They were less toxic to human cells than octyl β-d-glucopyranoside, a commonly used amphiphilic glucoside. Flow cytometry and confocal laser scanning microscopy revealed that the blockwise alkylated tetrasaccharide–organic QD complexes were stably attached to live cells. The affinity of compounds 1 and 2 to the live cell surface was slightly higher than that of compounds 3 and 4. Because the preparation of these carbohydrate–QD complexes is simple and does not require sophisticated equipment, and because the complexes can be autonomously attached to a wide spectrum of cell lines, they can be used as cell labeling reagents in biomedical studies.