title: Death and cell cycle progression are differently conditioned by the AgNP size in osteoblast-like cells.
abstract: Silver nanoparticles (AgNPs) are useful to a wide range of consumer's and medical products, due to their antimicrobial and anti-inflammatory activities. AgNPs have been used to prevent the microbial colonization, therefore decreasing the risk of infection, on implantable devices, tumor prostheses, bone cement and surgical instruments. However, the putative toxicity of AgNPs to bone cells is still poorly understood. Therefore, this study aimed to contribute to enlighten the role of ionic silver release of small sized NPs on the biological outcomes of bone cells, in particular to what concerns to induction of cytotoxic and genotoxic effects. To achieve that goal osteoblast-like MG-63 cells were exposed to well characterized PVP coated AgNPs of two different primary sizes (10nm and 20nm) and evaluated after 24 and 48h. Our results showed that, the smaller sized AgNPs (10nm) are more reactive and prone to form large aggregates, being therefore mandatory to provide a careful characterization of the particles, before the toxicity assessment. We also demonstrate that for short period exposures (up to 48h) ionic silver (from AgNO3) is more toxic than the corresponding dose of AgNP. However, when assessing longer term exposures by the clonogenic assay, we demonstrated the inverse effect, the AgNPs turn out being more toxic, completely inhibiting plate efficiency. Therefore, AgNPs toxicity cannot be attributed to the dissociated Ag+alone. Also, when comparing size-dependent effects, we demonstrate that AgNP20 were found to induce a cell cycle arrest at G0/G1 and apoptosis, while AgNP10 did not induce a cytostatic effect, but rather induced necrosis. Finally, combining the chemical and toxicological profiles of both AgNP sizes, we hypothesize that the size dependent AgNP toxicity may be associated in part with the NPs interference with the cell membranes and consequent uptake/adsorption processes.
authors: CESAM & Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal.
authors: F
authors: F
authors: Rosário
authors: Occupational and Environmental Toxicology, KU Leuven, Leuven, Belgium.
authors: P
authors: P
authors: Hoet
authors: Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto, Portugal. Electronic address: csantos@fc.up.pt.
authors: C
authors: C
authors: Santos
authors: CESAM & Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: holiveira@ua.pt.
authors: H
authors: H
authors: Oliveira
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001842:Bone and Bones / Q000166:cytology / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D006801:Humans; D053768:Metal Nanoparticles / Q000633:toxicity*; D009336:Necrosis / Q000139:chemically induced / Q000473:pathology; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D010316:Particle Size; D012834:Silver / Q000633:toxicity*
chemical_list: D012834:Silver
keywords: Apoptosis; Cell cycle; Clonogenic assay; Necrosis; PVP-coating; Silver nanoparticles