Charge- and size-dependent toxicity of silver nanoparticles to yeast and mammalian cells
Kaja Kasemets1,2, Anne Kahru2, Sandra Suppi2, Elisa Moschini1 and Paride Mantecca
1Department of Earth and Environmental Sciences, Research Center POLARIS, University of Milano Bicocca, 1 piazza della Scienza, 20126 Milan, Italy
2Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia (Questo indirizzo email è protetto dagli spambots. È necessario abilitare JavaScript per vederlo.)
Keywords: nanoparticles-cells interactions, internalization, yeast Saccharomyces cerevisiae BY4741, human alveolar epithelial cells A549
Nanotechnology is one of the fastest growing and most promising areas of the society. The number of consumer products on the market containing engineered nanoparticles is growingly increased and already exceeds 1000 (www.nanotechproject.org). Of the existing nanomaterials, silver nanoparticles (AgNPs) have the highest degree of commercialization, especially in antimicrobial applications. However, the toxicity mechanisms of differently sized, shaped and charged AgNPs to the different types of the cells are still largely unknown and remain to be explored. It is widely accepted that the toxicity of AgNPs is mostly driven by liberation of Ag-ions. In addition, it has been shown that the physicochemical interactions at the nano-bio interface may lead to the enhanced ionic stress, membrane damage and oxidative injury of the cell. In this presentation we will discuss how the different physicochemical properties of silver nanoparticles (AgNPs) as size, coating and charge may influence nanoparticles-cells interactions and their biological effects illustrating with our own results with yeast Saccharomyces cerevisiae and mammalian cells - human alveolar epithelial cells A549. Differently sized and coated AgNPs were studied: 10 and 80 nm, coated with citrate or branched-PEI, leading to negative or positive charge of NPs, respectively. Yeast and human alveolar epithelial cells A549 were exposed to the studied AgNPs in deionized water or in cell culture medium Opti-MEM without serum for 24 h at 30°C or 37°C, respectively. Confocal and electron microscopy techniques were used to visualize the NPs adsorption onto the cells surface and internalization.
Results showed that toxicity of AgNPs was crucially driven by the particles-cell interactions. Specific mechanisms are under investigation and will be discussed. The current study provides data that will be useful for the novel nanoparticles design strategies - safe-by-design and toxic-by-design.
This work was supported by Fondazione Cariplo (OverNanotox 2013-0987), Institutional funding of the Estonian Ministry of Education and Research IUT 23-5, ETF9001 and COST ES1205.