title: Cytotoxic response of platinum-coated gold nanorods in human breast cancer cells at very low exposure levels.
abstract: Because of unique optical behavior gold nanorods (GNRs) have attracted attention for the application in biomedical field such as bio-sensing, bio-imaging and hyperthermia. However, toxicological response of GNRs is controversial due to their different surface coating. Therefore, a comprehensive knowledge about toxicological profile of GNRs is necessary before their biomedical applications. First time, we investigated the toxic response of GNRs coated with platinum (GNRs-Pt) in human breast carcinoma (MCF-7) cells. Platinum coating further improves the optical and catalytic properties of GNRs. Assays such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT), neutral red uptake (NRU) and lactate dehydroganase (LDH) assays have shown that GNRs-Pt induced cytotoxicity at very low exposure levels (0.1-0.8 μg mL-1). Accumulation of cells in SubG1 phase and low mitochondrial membrane potential (JC-1 probe) in treated cells suggest that GNRs-Pt induced cell death via apoptotic pathway. Quantitative real-time PCR data demonstrated that mRNA expression of apoptotic genes (bax, caspase-3 and caspase-9) were up-regulated while anti-apoptotic gene bcl-2 was down-regulated in cells exposed to GNRs-Pt. We further observed the higher activity of caspase-3 and caspase-9 enzymes in GNRs-Pt treated cells supporting mRNA data. Moreover, N-acetyl cysteine (NAC) significantly attenuated the ROS generation and cytotoxicity induced by GNRs-Pt in MCF-7 cells suggesting that ROS might plays a crucial role in GNRs-Pt induced toxicity. This study warns of possible toxicity of GNRs even at very low exposure levels. Further investigations needed to explore potential mechanisms of this low dose toxicity phenomenon. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1344-1356, 2016.
authors.affiliation: King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, 11451, Saudi Arabia. maqusood@gmail.com.
authors.forename: Maqusood
authors.initials: M
authors.lastname: Ahamed
authors.affiliation: Department of Physics and Astronomy, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
authors.forename: Mohd Javed
authors.initials: MJ
authors.lastname: Akhtar
authors.affiliation: King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, 11451, Saudi Arabia.
authors.forename: M A Majeed
authors.initials: MA
authors.lastname: Khan
authors.affiliation: King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, 11451, Saudi Arabia.|Department of Physics and Astronomy, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
authors.forename: Hisham A
authors.initials: HA
authors.lastname: Alhadlaq
authors.affiliation: Research Chair in Drug Targeting and Treatment of Cancer Using Nanoparticles, Department of Biochemistry, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
authors.forename: Salman A
authors.initials: SA
authors.lastname: Alrokayan
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006046:Gold / Q000737:chemistry*; D006801:Humans; D061986:MCF-7 Cells; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D043942:Nanotubes / Q000737:chemistry* / Q000633:toxicity; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D010984:Platinum; D006046:Gold; D053148:Caspase 3; D053453:Caspase 9; D000111:Acetylcysteine
keywords: gold nanorods; human health; low exposure levels; platinum coating; toxicity