Aneuploidogenic effects and DNA oxidation induced in vitro by differently sized gold nanoparticles

Abstract

Gold nanoparticles (Au NPs) are used in many fields, including biomedical applications; however, no conclusive information on their potential cytotoxicity and genotoxicity mechanisms is available. For this reason, experiments in human primary lymphocytes and murine macrophages (Raw264.7) were performed exposing cells to spherical citrate-capped Au NPs with two different nominal diameters (5 nm and 15 nm). The proliferative activity, mitotic, apoptotic, and necrotic markers, as well as chromosomal damage were assessed by the cytokinesis-block micronucleus cytome assay. Fluorescence in situ hybridization with human and murine pancentromeric probes was applied to distinguish between clastogenic and aneuploidogenic effects. Our results indicate that 5 nm and 15 nm Au NPs are able to inhibit cell proliferation by apoptosis and to induce chromosomal damage, in particular chromosome mis-segregation. DNA strand breaks were detected by comet assay, and the modified protocol using endonuclease-III and formamidopyrimidine-DNA glycosylase restriction enzymes showed that pyrimidines and purines were oxidatively damaged by Au NPs. Moreover, we show a size-independent correlation between the cytotoxicity of Au NPs and their tested mass concentration or absolute number, and genotoxic effects which were more severe for Au NP 15 nm compared to Au NP 5 nm. Results indicate that apoptosis, aneuploidy, and DNA oxidation play a pivotal role in the cytotoxicity and genotoxicity exerted by Au NPs in our cell models.

Genotoxicity of TiO2nanoparticles assessed by mini-gel comet assay and micronucleus scoring with flow cytometry

“…As described by Fenech (13), Di Bucchianico et al . (14) and the OECD guideline 487 (15), 1000 cells were scored to evaluate cytostasis as a reduction of replication index of the treated cells compared to the negative control. The number of apoptotic, necrotic and mitotic cells per 1000 cells was also evaluated as a measure of cytotoxicity and cell proliferation.…”

Interaction of gold nanoparticles with proteins and cells

“…Citrate-coated Au NPs with sizes of 5 nm and 15 nm inhibit the proliferation of human primary lymphocytes and murine macrophages (Raw264.7). The reason was that Au NPs are able to trigger damage in chromosomes and apoptosis [116]. Moreover, 30 nm PEG-capped Au NPs can be further modified by arginine–glycine–aspartic acid peptide (RGD) and nuclear localization signal (NLS) peptide (RGD/NLS–Au NPs).…”

Effects of Size, Shape, Surface Charge and Functionalization on Cytotoxicity of Gold Nanoparticles

“…Very recently, Bucchianico and coauthors have studied the interactions of human primary lymphocytes and murine macrophages (RAW264.7) with di®erent sizes of spherical citrate-capped Au NPs (D core ¼ 5 nm and 15 nm). 61 They showed a size-independent correlation between the cytotoxicity of Au NPs and their tested mass concentration or absolute number, and genotoxic e®ects which were more severe for Au NP (D core ¼ 15 nm) compared to Au NP (D core ¼ 5 nm). They also found that the spherical citrate-capped Au NPs are able to inhibit cell proliferation by apoptosis and to induce chromosomal damage, in particular chromosome mis-segregation.…”