Human 3D Cultures as Models for Evaluating Magnetic Nanoparticle CNS Cytotoxicity after Short- and Repeated Long-Term Exposure.

Teresa Coccini,Marianna Roccio,Uliana De Simone,Arsenio Spinillo,Francesca Caloni,Laura Gribaldo

doi:10.3390/ijms19071993

Abstract

Since nanoparticles (NPs) can translocate to the brain and impact the highly vulnerable central nervous system (CNS), novel in vitro tools for the assessment of NP-induced neurotoxicity are advocated. In this study, two types of CNS spheroids have been developed from human D384 astrocyte- and SH-SY5Y neuronal-like cells, and optimized in combination with standard assays (viability readout and cell morphology) to test neurotoxic effects caused by Fe3O4NPs, as NP-model, after short- (24–48 h; 1–100µg/ml) and long-term repeated exposure (30days; 0.1–25µg/ml). Short-term exposure of 3D-spheroids to Fe3O4NP induced cytotoxicity at 10 µg/mL in astrocytes and 25 µg/mL neurons. After long-term repeated dose regimen, spheroids showed concentration- and time-dependent cell mortality at 10 µg/mL for D384 and 0.5 µg/mL for SH-SY5Y, indicating a higher susceptibility of neurons than astrocytes. Both spheroid types displayed cell disaggregation after the first week of treatment at ≥0.1 µg/mL and becoming considerably evident at higher concentrations and over time. Recreating the 3D-spatial environment of the CNS allows cells to behave in vitro more closely to the in vivo situations, therefore providing a model that can be used as a stand-alone test or as a part of integrated testing strategies. These models could drive an improvement in the species-relevant predictivity of toxicity testing.

Highlights

Nanotechnology is a sector where aspects related to impact on human and animal health and on the environment are of emerging concern, together with the result of possible consumer exposure to many nanoproducts present on the market [1,2] by different routes such as inhalation, ingestion, and dermal contact
The present study demonstrated for the first time that 3D spheroids of astrocytes and neurons of human origin are useful for toxicity screening after short- and long-term repeated exposures to nanoparticles
Fetal bovine serum (FBS), culture medium and all cell culture reagents were purchased from Carlo Erba Reagents (Carlo Erba Reagents S.r.l., Cornaredo, Italy), 75 cm2 tissue culture flask and ultralow attachment (ULA) 96-well round-bottomed plates were purchased from Corning (VWR International PBI, Milan, Italy)

Summary

Introduction

Nanotechnology is a sector where aspects related to impact on human and animal health and on the environment are of emerging concern, together with the result of possible consumer exposure to many nanoproducts present on the market [1,2] by different routes such as inhalation, ingestion, and dermal contact. Adverse effects on respiratory and cardiovascular systems following nanoparticles (NPs) exposure seem to be the most frequently reported [3,4]. Available evidence suggests incomplete effectiveness of the blood brain barrier protection of the brain against NP translocation [5,7]. Regardless of the route of exposure, NPs could reach the blood vessels and translocate to the brain [8,9]. The distribution of NPs in the bloodstream raises a particular concern of NP transfer from placenta to the fetal CNS [7] with serious damage as a consequence of direct exposure to NPs in utero [10]

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Results

Discussion

Conclusion