Alkilany Alaaldin M, Nagaria Pratik K, Hexel Cole R, Shaw Timothy J, Murphy Catherine J, Wyatt Michael D
Department of Chemistry and Biochemistry University of South Carolina Columbia, SC 29208, USA.
Small. 2009 Mar;5(6):701-8. doi: 10.1002/smll.200801546.
Gold nanorods of different aspect ratios are prepared using the growth-directing surfactant, cetyltrimethylammonium bromide (CTAB), which forms a bilayer on the gold nanorod surface. Toxicological assays of CTAB-capped nanorod solutions with human colon carcinoma cells (HT-29) reveal that the apparent cytotoxicity is caused by free CTAB in solution. Overcoating the nanorods with polymers substantially reduces cytotoxicity. The number of nanorods taken up per cell, for the different surface coatings, is quantitated by inductively coupled plasma mass spectrometry on washed cells; the number of nanorods per cell varies from 50 to 2300, depending on the surface chemistry. Serum proteins from the biological media, most likely bovine serum albumin, adsorb to gold nanorods, leading to all nanorod samples bearing the same effective charge, regardless of the initial nanorod surface charge. The results suggest that physiochemical surface properties of nanomaterials change substantially after coming into contact with biological media. Such changes should be taken into consideration when examining the biological properties or environmental impact of nanoparticles.
使用生长导向表面活性剂十六烷基三甲基溴化铵（CTAB）制备不同纵横比的金纳米棒，CTAB在金纳米棒表面形成双层结构。对用CTAB包覆的纳米棒溶液与人结肠癌细胞（HT - 29）进行的毒理学分析表明，明显的细胞毒性是由溶液中的游离CTAB引起的。用聚合物对纳米棒进行包覆可大幅降低细胞毒性。通过对洗涤后的细胞进行电感耦合等离子体质谱分析，对不同表面涂层的每个细胞摄取的纳米棒数量进行定量；每个细胞摄取的纳米棒数量从50到2300不等，这取决于表面化学性质。生物介质中的血清蛋白，很可能是牛血清白蛋白，吸附到金纳米棒上，导致所有纳米棒样品都带有相同的有效电荷，而不管初始纳米棒表面电荷如何。结果表明，纳米材料与生物介质接触后，其物理化学表面性质会发生显著变化。在研究纳米颗粒的生物学性质或环境影响时，应考虑到这些变化。
