Functionalized Nanoplastics (NPs) Increase the Toxicity of Metals in Fish Cell Lines.

Carmen González-Fernández,Francisco Guillermo Díaz Baños,María Ángeles Esteban,Alberto Cuesta

doi:10.3390/ijms22137141

Carmen González-Fernández, Francisco Guillermo Díaz Baños + Show 2 more

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https://doi.org/10.3390/ijms22137141

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Abstract

Nanoplastics (NPs) are one of the most abundant environment-threatening nanomaterials on the market. The objective of this study was to determine in vitro if functionalized NPs are cytotoxic by themselves or increase the toxicity of metals. For that, we used 50 nm polystyrene nanoparticles with distinct surface functionalization (pristine, PS-Plain; carboxylic, PS-COOH; and amino PS-NH2) alone or combined with the metals arsenic (As) and methylmercury (MeHg), which possess an environmental risk to marine life. As test model, we chose a brain-derived cell line (SaB-1) from gilthead seabream (Sparus aurata), one of the most commercial fish species in the Mediterranean. First, only the PS-NH2 NPs were toxic to SaB-1 cells. NPs seem to be internalized into the cells but they showed little alteration in the transcription of genes related to oxidative stress (nrf2, cat, gr, gsta), cellular protection against metals (mta) or apoptosis (bcl2, bax). However, NPs, mainly PS-COOH and PS-NH2, significantly increased the toxicity of both metals. Since the coexistence of NPs and other pollutants in the aquatic environment is inevitable, our results reveal that the combined effect of NPs with the rest of pollutants deserves more attention.

Highlights

IntroductionNanoplastics (NPs), particles smaller than 100 nm, have been identified in aquatic environments [2]
Because of their exceptional properties, including high durability, plastics are extensively produced, and parts of them are continuously discharged into the oceans [1].Over the last decade, nanoplastics (NPs), particles smaller than 100 nm, have been identified in aquatic environments [2]
In the cell culture medium, both functionalized NPs increased in size but maintained the nanoscale (

Summary

Introduction

Nanoplastics (NPs), particles smaller than 100 nm, have been identified in aquatic environments [2]. They are known to have a high surface area/volume ratio, which makes them highly reactive [3]. The risk of NPs is linked to their intrinsic features: surface charge, size, shape, functionalization, and coating [4] as well as to the physicochemical parameters of the surrounding media (pH, temperature and ionic concentration) and the presence or absence of natural colloids [5]. NPs are polydisperse and present an asymmetrical shape and an inhomogeneously charged surface [6]. NPs present negatively charged carboxylate surfaces [2,7]

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