Le Guével Xavier, Perez Perrino Monica, Fernández Tahia D, Palomares Francisca, Torres Maria-José, Blanca Miguel, Rojo Javier, Mayorga Cristobalina
Therapeutic Nanosystems, The Andalusian Centre for Nanomedicine and Biotechnology (BIONAND) , 29590 Málaga, Spain.
Glycosystems Laboratory, Instituto de Investigaciones Químicas (IIQ), CSIC-University of Seville , 41092 Seville, Spain.
ACS Appl Mater Interfaces. 2015 Sep 23;7(37):20945-56. doi: 10.1021/acsami.5b06541. Epub 2015 Sep 8.
We report the synthesis and characterization of gold nanoclusters (Au NCs) stabilized by a mixture of zwitterionic and multivalent mannose ligands. Characterization of this carbohydrated nanosystem confirms its small size (∼2 nm), intense red-NIR fluorescence, relatively high affinity to lectin (ConA), and stability in physiological media. Cell studies performed using human-monocyte-derived dendritic cells (DCs) show that Au NC uptake efficiency is greatly enhanced by the presence of surface carbohydrate (>250% compared to noncarbohydrated Au NCs), allowing their detection in cells by fluorescence following incubation with concentrations as low as 1 μg mL(-1). Investigation using electron microscopy and pharmacological inhibitors indicates that Au NC uptake is mediated by multiple endocytic pathways involving the engulfment of Au NCs into endosomes and partial transport to lysosomes. Results show that clathrin- and F-actin-dependent pathways play major roles in Au NC uptake by DCs, regardless of whether or not they are coated with carbohydrates. In contrast, a specific C-lectin inhibitor induces a 60% decrease in DC particle uptake only for the carbohydrate-coated Au NCs. This study demonstrates that the combination of ultrasmall gold NCs and functionalization with multivalent mannose ligands results in greatly enhanced human DC targeting, presumably due to increased diffusion and target cell binding, respectively.
我们报道了由两性离子和多价甘露糖配体混合物稳定的金纳米团簇（Au NCs）的合成与表征。对这种碳水化合物化纳米系统的表征证实了其尺寸小（约2 nm）、强烈的红-近红外荧光、对凝集素（伴刀豆球蛋白A）的相对高亲和力以及在生理介质中的稳定性。使用人单核细胞衍生的树突状细胞（DCs）进行的细胞研究表明，表面碳水化合物的存在极大地提高了Au NC的摄取效率（与无碳水化合物的Au NCs相比提高了>250%），使得在与低至1 μg mL(-1)的浓度孵育后能够通过荧光在细胞中检测到它们。使用电子显微镜和药理抑制剂进行的研究表明，Au NC的摄取是由多种内吞途径介导的，包括将Au NC吞噬到内体中并部分转运到溶酶体。结果表明，网格蛋白和F-肌动蛋白依赖性途径在DC摄取Au NC中起主要作用，无论它们是否被碳水化合物包被。相比之下，一种特异性C-凝集素抑制剂仅使碳水化合物包被的Au NC的DC颗粒摄取减少60%。这项研究表明，超小金纳米团簇与多价甘露糖配体功能化的结合导致人DC靶向性大大增强，这可能分别是由于扩散增加和与靶细胞结合增加所致。
