Cytotoxic response of platinum-coated gold nanorods in human breast cancer cells at very low exposure levels.

Journal: Environmental toxicology
PMID: 25846798

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 ). 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

  • Maqusood Ahamed
    King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, 11451, Saudi Arabia. maqusood@gmail.com.
  • Mohd Javed Akhtar
    Department of Physics and Astronomy, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
  • M A Majeed Khan
    King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, 11451, Saudi Arabia.
  • Hisham A Alhadlaq
    King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, 11451, Saudi Arabia.
  • Salman A Alrokayan
    3Department of Biochemistry, College of Science, King Saud University, PO Box 2455, Riyadh, 11451 Saudi Arabia.

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