Cytotoxicity and Immunological Response of Gold and Silver Nanoparticles of Different Sizes

Abstract

The immunological response of macrophages to physically produced pure Au and Ag nanoparticles (NPs) (in three different sizes) is investigated in vitro. The treatment of either type of NP at > or =10 ppm dramatically decreases the population and increases the size of the macrophages. Both NPs enter the cells but only AuNPs (especially those with smaller diamter) up-regulate the expressions of proinflammatory genes interlukin-1 (IL-1), interlukin-6 (IL-6), and tumor necrosis factor (TNF-alpha). Transmission electron microscopy images show that AuNPs and AgNPs are both trapped in vesicles in the cytoplasma, but only AuNPs are organized into a circular pattern. It is speculated that part of the negatively charged AuNPs might adsorb serum protein and enter cells via the more complicated endocytotic pathway, which results in higher cytotoxicity and immunological response of AuNPs as compared to AgNPS.

Micromorphological cellular responses of MC3T3-E1 and RAW264.7 after exposure to water-dispersible silver nanoparticles stabilized by metal-carbon σ-bonds

“…Studies using various cell lines reported that Ag-NPs affected mitochondrial function and induced cell necrosis or apoptosis 24,25) . However, other investigators found no such cytotoxic effects of Ag-NPs on living cells 26) . In addition, weakened or absent cell responses have been reported with other nanoparticles such as Au-NPs 27) and nanodiamonds 28) , suggesting that the cytotoxicity is affected by the physicochemical characteristics of the particles (e.g.…”

“…their size, size distribution, shape, state of dispersion, physical and chemical properties, surface area and porosity, surface chemistry) and by cell characteristics (e.g. cell line, number of cells per well, and the period of culture before and/or after exposure to nanoparticles) 17,[24][25][26]29,30) . A recent study showed a decrease in MC3T3-E1 cell viability after exposure to Ag-NPs using the WST-8 assay 31) , but this study used different test conditions for cell culture and exposure to Ag-NPs, which may explain the disparity between their results and ours.…”

“…Phagocytosis and pinocytosis are distinguished by the particle size or vesicles. When uptake of NPs occurs via receptor-mediated endocytosis, the trapped particles coat the cell near the membrane inside the vesicle 26) . However, the trapped particles would lead to aggregation in the vesicle in the case of simple pinocytosis or endocytosis 26) .…”

“…When uptake of NPs occurs via receptor-mediated endocytosis, the trapped particles coat the cell near the membrane inside the vesicle 26) . However, the trapped particles would lead to aggregation in the vesicle in the case of simple pinocytosis or endocytosis 26) . Based on these previous results, we conclude that the Ag-NP uptake in the present study is morphologically most like endocytosis, suggesting that this is the main mechanism of uptake.…”

Effect of oral administration of commercial gold nanocolloid on peripheral blood leukocytes in mice

“…The higher reactivity of nanoparticles than bulk gold can be a cause of increased ROS (reactive oxygen species) formation inside cells and oxidative stress development, especially in phagocytes, which are particularly predisposed to remove foreign particles from an organism (Brown et al 2008, Yen et al 2009, Lasagna-Reeves et al 2010, Zhang et al 2010, Thakor et al 2011, Gerber et al 2013, Chueh et al 2014.…”