Mutagenicity testing in non-transformed and transformed human breast cell lines after exposure to silver nanoparticles in combination with aluminum chloride, butylparaben, or di-n-butylphthalate

Introduction Application of silver nanoparticles (AgNP) in cosmetic products is growing rapidly, however very little is known about their biological interactions with other cosmetic ingredients. Considering in vitro and in... [ view full abstract ]

Introduction
Application of silver nanoparticles (AgNP) in cosmetic products is growing rapidly, however very little is known about their biological interactions with other cosmetic ingredients. Considering in vitro and in vivo studies demonstrating accumulation of AgNP in tissues and DNA damage in mammalian cells following exposure to AgNP, the safety issue of using different cosmetic formulations containing AgNP becomes an urgent issue. The aim of this study was to assess potential mutagenic effects of AgNP in combination with other ingredients/impurities of cosmetic products such as: aluminum chloride (AlCl3), butylparaben (BPB) and dibutylphthalate (DBPH).
Methods
AgNP were characterized using the UV-Vis spectroscopy, dynamic light scattering (DLS) and scanning transmission electron microscopy (STEM). The mean size of metallic core of two citrate stabilized AgNP was 15 ± 3 nm and 45 ± 10 nm. The hydrodynamic size of the particles was 19 ± 4 nm and 58 ± 10 nm. Mutagenicity of the AgNP in combination with AlCl3, BPB, or DBPH in three human cell lines, i.e. MCF-7, MDA-MB-231 (both cell types representing breast adenocarcinoma, estrogen receptor(ER)-positive and ER-negative, respectively) and MCF-10A (non-transformed cells), was measured using the in vitro micronucleus test. For comparison, an effect of silver nitrate was also assessed.
Results
Considerable differences in cytotoxicity of both AgNP on normal and cancer cell lines were seen. For example, the highest acceptable concentration (% cytostasis <55%) of AgNP15 used for a 24 h exposure of MCF-10A cells was 47.1 μg/ml, while for MCF-7 and MDA-MB-321 it was 1 μg/ml or 1.2 μg/ml, respectively. The nanoparticles did not show any mutagenic effect neither in combination with the AlCl3 (≤500 μM), BPB (≤200 μM) nor DBPH (≤35 μM). Silver nitrate did not show any mutagenicity at up to acceptable concentrations of 1.5 μg/ml (MCF-10A) or 1 μg/ml (MCF-7 and MDA-MB-321).
Discussion
The results indicate that the AgNP do not show mutagenic activity in the breast cells lines and that selected cosmetic additives/impurities do not modulate the mutagenic/cytotoxic potential of AgNP.
Funded by the Polish National Science Centre (grant 2012/07/B/NZ7/04197). In this study the apparatus purchased in POIG.01.03.01-00-004/08 project were used.