Fertility and Iron Bioaccumulation in Drosophila melanogaster Fed with Magnetite Nanoparticles Using a Validated Method

Fernanda Pilaquinga,José Luis Gutiérrez-Coronado,Sofía Cárdenas,María De Las Nieves Piña,Eliza Jara,Doris Vela,Alexis Debut,Jeroni Morey

doi:10.3390/molecules26092808

Abstract

Research on nanomaterial exposure-related health risks is still quite limited; this includes standardizing methods for measuring metals in living organisms. Thus, this study validated an atomic absorption spectrophotometry method to determine fertility and bioaccumulated iron content in Drosophila melanogaster flies after feeding them magnetite nanoparticles (Fe3O4NPs) dosed in a culture medium (100, 250, 500, and 1000 mg kg−1). Some NPs were also coated with chitosan to compare iron assimilation. Considering both accuracy and precision, results showed the method was optimal for concentrations greater than 20 mg L−1. Recovery values were considered optimum within the 95–105% range. Regarding fertility, offspring for each coated and non-coated NPs concentration decreased in relation to the control group. Flies exposed to 100 mg L−1 of coated NPs presented the lowest fertility level and highest bioaccumulation factor. Despite an association between iron bioaccumulation and NPs concentration, the 500 mg L−1 dose of coated and non-coated NPs showed similar iron concentrations to those of the control group. Thus, Drosophila flies’ fertility decreased after NPs exposure, while iron bioaccumulation was related to NPs concentration and coating. We determined this method can overcome sample limitations and biological matrix-associated heterogeneity, thus allowing for bioaccumulated iron detection regardless of exposure to coated or non-coated magnetite NPs, meaning this protocol could be applicable with any type of iron NPs.

Highlights

Nanotechnology has made it possible for biomedical applications and diagnostics to create, characterize, and modify the functional properties of nanoparticles (NPs) [1]
Our findings show that iron bioaccumulation in flies is related to NPs concentration exposure, with one exception at 500 mg kg−1, where there was a notable decrease in Fe buildup
This study validated an analytical method for the determination of the bioaccumulation of iron in Drosophila melanogaster flies fed with magnetite NPs; this protocol proved to be versatile for the direct measurement of metal content in flies, as it can be applied with confidence for both coated and non-coated NPs to obtain a valid correlation between the toxicant and the observable effect

Summary

Introduction

Nanotechnology has made it possible for biomedical applications and diagnostics to create, characterize, and modify the functional properties of nanoparticles (NPs) [1]. Fe3O4 is a typical magnetic iron oxide with an inverse spinel structure [9], and at room temperature, its electrons can hop in the octahedral sites between 2+ and 3+ ion oxidation states, making magnetite an important element of the semi-metallic material class [10]. These magnetic NPs can be dispersed into suitable solvents with the proper surface coating, forming homogeneous suspensions called ferrofluids [11]. Current potential applications of magnetic NPs are continuously advancing and include guided drug and gene delivery [13], tissue engineering [14], magnetic resonance imaging [15], enzyme immobilization [16], and protein and metal adsorption [17]

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Conclusion