title: Cytogenetic evaluation of gold nanorods using Allium cepa test.
abstract: 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.
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: A
authors.initials: A
authors.lastname: Rajeshwari
authors.affiliation: School of Bioscience and Technology, VIT University, Vellore, India.
authors.forename: Barsha
authors.initials: B
authors.lastname: Roy
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: Natarajan
authors.initials: N
authors.lastname: Chandrasekaran
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India. Electronic address: amit.mookerjea@gmail.com.
authors.forename: Amitava
authors.initials: A
authors.lastname: Mukherjee
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D002869:Chromosome Aberrations / Q000139:chemically induced; D020732:Cytogenetic Analysis; D006046:Gold / Q000633:toxicity; D015227:Lipid Peroxidation / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity* / Q000648:ultrastructure; D008940:Mitotic Index; D043942:Nanotubes / Q000737:chemistry / Q000633:toxicity / Q000648:ultrastructure; D019697:Onions / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011092:Polyethylene Glycols / Q000737:chemistry
chemical_list: D002593:Cetrimonium Compounds; D011092:Polyethylene Glycols; D006046:Gold; D000077286:Cetrimonium
keywords: Allium cepa; Capping agent; Gold nanorods; Mitotic index; Oxidative stress; Peroxidation of lipid