Hospital Universitario La Paz-IdiPAZ, Paseo de la Castellana 261, 28046 Madrid, Spain.
Acta Biomater. 2011 Oct;7(10):3645-55. doi: 10.1016/j.actbio.2011.06.018. Epub 2011 Jun 17.
Gold nanoparticles (Au NPs) are promising vectors for gene delivery applications. In order to gain insight on the influence of particle size on cell transfection, Au NPs were combined with poly(ethylenimine) (PEI) to prepare two sets of PEI-coated Au NPs having particle-size distributions centered at about 6 nm (<10nm Au-PEI NPs) or 70 nm (<100 nm Au-PEI NPs), respectively. Au-PEI NPs were coupled to a variety of plasmids carrying reporter or suicide genes to prepare Au-PEI NPs/DNA complexes, and human osteosarcoma Saos-2 cells were used to investigate the performance of the Au-PEI NPs as transfection vectors in serum-containing media. The conjugates of DNA with both types of Au-PEI NPs were found to be negatively charged. In spite of the electrostatic repulsion that occurs between the surface of the cell and the surface of the plasmid-conjugated NPs, cell internalization was observed for both kinds of Au-PEI NPs. Cells were efficiently transfected with complexes derived from <10 nm Au-PEI NPs, but not with the <100 nm Au-PEI NPs. Large aggregates of NPs associated with DNA were found in endocytic vesicles of cells incubated with <100 nm Au-PEI NPs, while the success of the smaller Au-PEI NPs as transfection vectors was related to their lower agglomeration state inside cells and to endosomal escape of DNA.
金纳米粒子（Au NPs）是基因传递应用中很有前途的载体。为了深入了解粒径对细胞转染的影响，将 Au NPs 与聚（亚乙基亚胺）（PEI）结合，分别制备了两组粒径分布中心约为 6nm（<10nm Au-PEI NPs）或 70nm（<100nm Au-PEI NPs）的 PEI 包覆的 Au NPs。将 Au-PEI NPs 与携带报告基因或自杀基因的各种质粒偶联，制备 Au-PEI NPs/DNA 复合物，并用人骨肉瘤 Saos-2 细胞研究 Au-PEI NPs 作为转染载体在含血清培养基中的性能。发现两种类型的 Au-PEI NPs 与 DNA 的缀合物均带负电荷。尽管细胞表面和与质粒偶联的 NPs 表面之间存在静电排斥，但观察到两种类型的 Au-PEI NPs 均发生了细胞内化。源自<10nm Au-PEI NPs 的复合物可有效转染细胞，但源自<100nm Au-PEI NPs 的复合物则不行。与<100nm Au-PEI NPs 孵育的细胞内发现与 DNA 相关的大 NPs 聚集物存在于内吞小泡中，而较小的 Au-PEI NPs 作为转染载体的成功与它们在细胞内较低的聚集状态和 DNA 的内体逃逸有关。
