PVP-coated silver nanoparticles and silver ions induce reactive oxygen species, apoptosis and necrosis in THP-1 monocytes.
The objective of the present study was to investigate the toxicity of silver nanoparticles (Ag NPs) in vitro. Silver ions (Ag+) have been used in medical treatments for decades whereas Ag NPs have been used in a variety of consumer products within recent years. This study was undertaken to compare the effect of well characterized, PVP-coated Ag NPs (69 nm +/- 3 nm) and Ag+ in a human monocytic cell line (THP-1). Characterization of the Ag NPs was conducted in both stock suspension and cell media with or without serum and antibiotics. By using the flowcytometric annexin V/propidium iodide (PI) assay, both Ag NPs and Ag+ were shown to induce apoptosis and necrosis in THP-1 cells depending on dose and exposure time. Furthermore, the presence of apoptosis could be confirmed by the TUNEL method. A number of studies have implicated the production of reactive oxygen species (ROS) in cytotoxicity mediated by NPs. We used the fluorogenic probe, 2',7'-dichlorofluorescein to assess the levels of intracellular ROS during exposure to Ag NPs and Ag+. A drastic increase in ROS levels could be detected after 6-24h suggesting that oxidative stress is an important mediator of cytotoxicity caused by Ag NPs and Ag+.
Foldbjerg
Rasmus
R
Department of Environmental and Occupational Medicine, Institute of Public Health, Aarhus University, Bartholins Allé 2, Bygn. 1260, 8000 Aarhus, Denmark. rfol@mil.au.dk
Olesen
Ping
P
Hougaard
Mads
M
Dang
Duy Anh
DA
Hoffmann
Hans Jürgen
HJ
Autrup
Herman
H
D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D006801:Humans; D020287:In Situ Nick-End Labeling; D008027:Light; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D053758:Nanoparticles; D009336:Necrosis / Q000473:pathology; D010316:Particle Size; D011143:Polyvinyl Chloride / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012542:Scattering, Radiation; D012834:Silver / Q000494:pharmacology*
D017304:Annexin A5; D005456:Fluorescent Dyes; D017382:Reactive Oxygen Species; D012834:Silver; D011143:Polyvinyl Chloride