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Plastic waste in different environments has been constantly transforming into microplastic/nanoplastic (MNPLs). As they may coexist with other contaminants, they may behave as vectors that transport various toxic trace elements, including metals. Because the impact of exposure to such matter on health still remains elusive, the abundant presence of MNPLs has lately become a pressing environmental issue. Researchers have been utilizing Drosophila melanogaster as a dynamic in vivo model in genetic research for some time. The fly has also recently gained wider recognition in toxicology and nanogenotoxicity studies. The use of nanoparticles in numerous medical and consumer products raises serious concern, since many in vitro studies have shown their toxic potential. However, there is rather limited in vivo research into nanomaterial genotoxicity using mice or other mammalians owing to high costs and ethical concerns. In this context, Drosophila, thanks to its genetic tractability, short life span, with its entire life cycle lasting about 10 days, and distinct developmental stages, renders this organism an excellent model in testing toxic effects mediated by MNPLs. This review therefore aims to encourage research entities to employ Drosophila as a model in their nanogenotoxicity experiments focusing on impact of MNPLs at the molecular level. Drosophila as a model organism shows similar aspects around 75–77% of the genes involved in human diseases such as intestinal infections, cardiovascular diseases, neurodegenerative disorders, cancer, Alzheimer diseases, and Parkinson. The current review focuses on our current knowledge derived from recent in vivo studies to examine the impact of several MNPLs and heavy metals on Drosophila in terms of the genetic, molecular, and cellular levels; the possible mechanisms; and potential adverse effects as a non‐target organism. [ABSTRACT FROM AUTHOR]

In the last two decades the production and use of nanomaterials (NMs) has impressively increased. Their small size, given a mass equal to that of the corresponding bulk material, implies an increase in the surface area and consequently in the number of atoms that can be reactive. They possess different physical, chemical and biological properties compared to bulk materials of the same composition, which makes them very interesting and valuable for many different applications in technology, energy, construction, electronics, agriculture, optics, paints, textiles, food, cosmetics, medicine... Toxicological assessment of NMs is crucial; the same properties that make them interesting also make them potentially harmful for health and the environment. However, the term NM covers many different kinds of particle , and so there is no simple, standard approach to assessing their toxicity. NMs can enter the cell, interact with cell components and even penetrate the nucleus and interfere with the genetic material. Among the different branches of toxicology, genotoxicity is a main area of concern since it is closely related with the carcinogenic potential of compounds. The Organisation for Economic Co-operation and Development (OECD) has published internationally agreed in vitro and in vivo validated test methods to evaluate different genotoxic endpoints of chemicals, including chromosome and gene mutations, and DNA breaks. However not all the assays are suitable to study the genotoxic potential of NMs as has been shown by the OECD Working Party on Manufactured Nanomaterials (WPMN). Moreover, alterations to DNA bases, which are precursors to mutations and of great importance in elucidating the mechanism of action of NMs, are not covered by the OECD guidelines. The in vivo standard comet assay (which measures DNA breaks and alkali-labile sites) was included in the OECD assays battery in September 2014 while the in vitro standard comet assay is currently under validation. The comet assay has not been yet proposed as an appropriate test to check the genotoxic potential of NMs, though at a research level it is the most used in vitro assay and the second most used in vivo assay. Moreover, the combination of the comet assay with enzymes that convert altered bases to breaks allows the identification of DNA damage induced by secondary mechanisms (e.g. oxidative stress induced by inflammation), which is very relevant in the case of NMs. Possible problems with the use of the comet assay have been suggested: NMs have been detected in close association with comets, and might interact with the DNA; or NMs might inhibit the action of enzymes. However, control experiments have not confirmed that these interactions are significant.