利用三步晶种生长法合成长径比约为14的大长径比金纳米棒(GNR),利用巯基十一酸(MUDA)对金纳米棒表面进行了生物适应性修饰,并在宏观水平上研究了修饰前后的金纳米棒在对细胞活性的影响.利用单细胞方法分别考察了修饰后的纳米金棒对细胞贴壁过程、增殖速率、细胞内ROS以及骨架排布的影响.虽然MTT细胞活性结果显示内吞后的金纳米棒对细胞无毒,但单细胞毒性分析方法发现,不同浓度纳米金棒对早期贴壁过程有较小的影响,且内吞的纳米金棒在一定程度上促进了细胞的增殖,而高浓度下纳米金棒引起了细胞内ROS含量的升高,并破坏了细胞内骨架纤维排布.本研究建立了用单细胞行为分析纳米颗粒对细胞毒性的方法,证明了以往仅仅利用MTT等宏观手段分析纳米材料生物适应性是不足的.纳米材料在生物医学领域的进一步应用还应考虑单细胞及分子水平上的毒性效应.%We have synthesized high-aspect-ratio gold nanorods (GNR) by using a three-step seed-mediated growth method. The aspect ratio of the GNRs is approximately 14. The modification of the GNRs was achieved by replacing the CTAB molecules on the surface of gold nanorods with the 11-mercaptoundecanoic (MUDA) molecules. The cytotoxicity of the as-prepared GNRs and their effects on endocytosis, adhesion, proliferation, intracellular reactive oxygen species (ROS) level and cytoskeleton of the cells were studied. Interestingly, by using the 3-(4, 5-dimethylthiazol-2-yl) 2,5-diphenyl-tetrazolium bromide (MTT) assay, the GNRs did not show a significant toxicity to HeLa cells. However, single cell viability assays showed that GNR uptake could influence the cell adhesion at the early stage, though the effect was not much, and the cell proliferation was promoted to some degree. Moreover, large amounts of GNR uptake will lead to increased intracellular ROS level and impaired the cell skeleton.
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