富G寡聚核苷酸修饰的金纳米粒子与细胞相互作用的研究

Study on Interaction of G-rich Oligonucleotides Modified Gold Nanoparticles with Cells

通过Au-S键将两种链长一致、序列不同的富鸟嘌呤(G)单链寡聚核苷酸PolyG_1和PolyG_2分别修饰到13 nm金纳米粒子(GNPs)表面,合成了两种单链寡聚核苷酸(ssDNAs)与GNPs复合物(PolyG_1-GNPs和PolyG_2-GNPs)。所合成的PolyG_1-GNPs和PolyG_2-GNPs在复杂分散介质中具有良好的胶体稳定性。采用紫外-可见吸收光谱、细胞透射电镜和电感耦合等离子体质谱等分析方法,考察ss DNA序列对PolyG_1-GNPs和PolyG_2-GNPs与细胞相互作用的影响。结果表明,PolyG_1-GNPs和PolyG_2-GNPs均具有较低的细胞毒性,并表现与能量相关的细胞内吞行为,ssDNA的序列决定PolyG_1-GNPs和PolyG_2-GNPs的细胞吞噬量及其在细胞内的分散状态,具有G4二级结构的PolyG_2能够显著增加细胞对其所修饰的GNPs的吞噬量和GNPs在细胞中的稳定性。

Two kinds of ssDNA-GNPs(PolyG 1-GNPs and PolyG 2-GNPs)were synthesized by modification of two different G-rich single-strand oligonucleotides(PolyG 1 and PolyG 2)onto 13-nm gold nanoparticles(GNP)surface through formation of the sulfur-gold covalent bond,respectively.The as-prepared PolyG 1-GNPs and PolyG 2-GNPs had reasonable colloidal stability in complex dispersing matrices.The effect of ssDNA sequence on the interaction between ssDNA-GNPs and cells was systematically investigated by UV-vis absorption spectroscopy,cellular transmission electronic microscopy and inductively coupled plasma mass spectrometry.The experimental results showed that both of the as-prepared PolyG 1-GNPs and PolyG 2-GNPs had low cytotoxicity and exhibited energy related endocytosis.In addition,the cellular internalization amount and dispersibility of ssDNA-GNPs were strongly affected by the sequences of immobilized ssDNA.PolyG 2 with G4 secondary structure could significantly increase the cellular internalization amount and intracellular stability of PolyG 2-GNPs.