Rajeshwari A, Roy Barsha, Chandrasekaran Natarajan, Mukherjee Amitava
Centre for Nanobiotechnology, VIT University, Vellore, India.
School of Bioscience and Technology, VIT University, Vellore, India.
Plant Physiol Biochem. 2016 Dec;109:209-219. doi: 10.1016/j.plaphy.2016.10.003. Epub 2016 Oct 6.
The current study reveals the impact of gold nanorods (NRs) capped with CTAB (cetyltrimethylammonium bromide) or PEG (polyethylene glycol) on Allium cepa. The morphology and surface charge of CTAB- and PEG-capped gold NRs were characterized by electron microscopic and zeta potential analyses. The chromosomal aberrations like clumped chromosome, chromosomal break, chromosomal bridge, diagonal anaphase, disturbed metaphase, laggard chromosome, and sticky chromosome were observed in the root tip cells exposed to different concentrations (0.1, 1, and 10 μg/mL) of CTAB- and PEG-capped gold NRs. We found that both CTAB- and PEG-capped gold NRs were able to induce toxicity in the plant system after 4-h interaction. At a maximum concentration of 10 μg/mL, the mitotic index reduction induced by CTAB-capped gold NRs was 40-fold higher than that induced by PEG-capped gold NRs. The toxicity of gold NRs was further confirmed by lipid peroxidation and oxidative stress analyses. The unbound CTAB also contributed to the toxicity in root tip cells, while PEG alone shows less toxicity to the cells. The vehicle control CTAB contributed to the toxic effects in root tip cells, while PEG alone did not show any toxicity to the cells. The results revealed that even though both the particles have adverse effects on A. cepa, there was a significant difference in the mitotic index and oxidative stress generation in root cells exposed to CTAB-capped gold NRs. Thus, this study concludes that the surface polymerization of gold NRs by PEG can reduce the toxicity of CTAB-capped gold NRs.
当前的研究揭示了用十六烷基三甲基溴化铵（CTAB）或聚乙二醇（PEG）包覆的金纳米棒（NRs）对洋葱的影响。通过电子显微镜和zeta电位分析对CTAB包覆和PEG包覆的金纳米棒的形态和表面电荷进行了表征。在暴露于不同浓度（0.1、1和10μg/mL）的CTAB包覆和PEG包覆的金纳米棒的根尖细胞中观察到了染色体畸变，如染色体聚集、染色体断裂、染色体桥、对角后期、中期紊乱、落后染色体和粘连染色体。我们发现，CTAB包覆和PEG包覆的金纳米棒在相互作用4小时后都能够在植物系统中诱导毒性。在最大浓度为10μg/mL时，CTAB包覆的金纳米棒诱导的有丝分裂指数降低比PEG包覆的金纳米棒高40倍。通过脂质过氧化和氧化应激分析进一步证实了金纳米棒的毒性。未结合的CTAB也对根尖细胞的毒性有贡献，而单独的PEG对细胞的毒性较小。载体对照CTAB对根尖细胞有毒性作用，而单独的PEG对细胞没有显示出任何毒性。结果表明，尽管两种颗粒对洋葱都有不利影响，但在暴露于CTAB包覆的金纳米棒的根细胞中，有丝分裂指数和氧化应激产生存在显著差异。因此，本研究得出结论，PEG对金纳米棒的表面聚合可以降低CTAB包覆的金纳米棒的毒性。
