The increasingly common use of nanoparticles (NPs) in the industry has generated the need for studies that provide more information about their environmental impact. Nanotechnology can be defined as: the manipulation, precision, placement, measurement, modelling, or manufacture of sub-100 nanometer scale matter (Meyer et al. 2001). These particles exhibit different properties compared to the same materials on a macro or micrometric scale. When a material reduces its size to below 100 nm, its characteristics can be altered (Bondarenko et al. 2013).
Among these nanoparticles there are copper oxide (CuO), zinc oxide (ZnO) and graphene. The main goal of this study is to evaluate if there are effects of cytotoxicity and genotoxicity of the mentioned molecules. The selected molecules have been used in the industry in several ways and during the last years tones of them have been produced. Therefore, it is crucial to rule out potential damage caused by these molecules
The exploration of potential hazardous effects associated with CuO NPs remains limited in comparison to other nanoparticle counterparts, likely due to their relatively lower usage quantities compared with other NPs (Kahru and Savolainen 2010). It is reasonable to infer that the production volume of CuO NPs is high but also comparatively modest. The predominant and distinct application niche for CuO NPs revolves around electronics and technology, encompassing semiconductors, electronic chips, and heat transfer nanofluids, owing to the exceptional thermophysical properties of CuO (Ebrahimnia-Bajestan et al. 2011; Bondarenko et al. 2013). Furthermore, CuO NPs have been proposed for diverse applications, including gas sensors (Li et al. 2008), catalytic processes (Carnes and Klabunde 2003), solar cells, and lithium batteries (Guo et al. 2009; Sau et al. 2010). Research indicates that CuO NPs exhibit inhibitory effects on microorganism growth and demonstrate antiviral properties (Borkow and Gabbay 2004). Consequently, the integration of CuO NPs into face masks, wound dressings, and socks has been explored to confer biocidal properties (Borkow et al. 2009).
The ZnO, the chemical formula for zinc oxide, is an inorganic substance presented in the form of a white powder that is insoluble in water (Ahmad et al. 2020). This versatile material finds application in various industries, including paints, adhesives, plastics, sealants, pigments, food, ointments, batteries, ferrites, and fire retardants. While zincite mineral in the Earth's crust contains ZnO, the majority used in commercial applications is synthesized. Zinc and oxygen correspond to the second and sixth groups in the periodic table. In materials science, ZnO is commonly referred to as a II-VI semiconductor. With unique optical characteristics, it possesses a large bandgap of 3.3 eV in the ultraviolet spectrum, exhibits high binding energy at room temperature, and demonstrates high electrical conductivity of n-type (Al Jabri et al. 2022).
It is well known that Graphene has found extensive applications in various nanobiotechnological fields, including environmental applications, biomedicine, and biotechnology (Bitounis et al. 2013). The scientific literature on graphene has witnessed a significant surge since its discovery in 2004, with the number of papers surpassing 8,500 in 2012 according to a topic search on the ISI Web of Science. In comparison to other carbon materials, graphene-based systems, though relatively young in development, exhibit substantial potential for numerous biomedical applications. Notably, the evaluation of the in vitro and in vivo toxicity of graphenes in recent studies has yielded conflicting results, with both toxic and non-toxic effects observed simultaneously. This divergence highlights the necessity of avoiding broad generalizations, as the safety risks associated with graphenes are contingent upon the specific type of material under analysis. It is imperative to recognize that conclusive assessments must be approached cautiously, considering the nuanced nature of graphene's impact (Sreeprasad and Pradeep 2012; Seabra et al. 2014).
The scientific community currently faces a substantial gap in understanding the potential adverse effects of NPs, which significantly lags behind the advancements in nanotechnology development (Shvedova et al. 2010; Kahru and Ivask 2013). Moreover, the available data on nanotoxicity lack consistency due to variations in experimental approaches across different articles, hindering the comparability of results. To tackle these issues, there is an ongoing discourse within the nanotoxicology community regarding the need for comprehensive guidelines in nanotoxicology research and the establishment of common parameters to be addressed in all nanotoxicological articles (Schrurs and Lison, 2012). For all these reasons, this article will contribute new information on the toxicity of CuO, ZnO, and Graphene nanoparticles.
It is well accepted that further studies are needed to extend our toxicological knowledge on the newly developed nanoparticles or nanoenabled products. Accordingly, we aimed to investigate in vitro toxicology of various NPs, which may have catalytic or biological applications. Nanoparticles possess a heightened ability to traverse through an organism via inhalation compared to larger particles, potentially exhibiting increased toxicity due to their expanded surface area and distinct structural/chemical properties. Gradoń et al. (2000) established a correlation between the presence of nanoparticles in workplace air, inhaled by individuals, and instances of acute morbidity and even mortality in the elderly.
Furthermore, NPs, following inhalation exposure, have been documented to travel through the nasal nerves to reach the brain (Kreuter et al. 2002; Oberdörster et al. 2005). In a separate investigation, it was revealed that inhaled ultrafine 99mtechnetium-labeled carbon particles rapidly diffused into the systemic circulation, peaking between 10 and 20 minutes and maintaining this level for up to 60 minutes (Nemmar et al.). In addition reports indicate that NPs present in food can traverse gut lymphatics and redistribute to other organs more readily than larger particles (Jani et al. 1990; Hillery et al. 1994). In essence, NPs may be deposited into human cells through nasal inhalation or digestion pathways, exerting effects on various organs and tissues. Another study emphasized that the observed biological effects were influenced by the size and composition of NPs (Wottrich et al. 2004).