Cytotoxicity of Au, ZnO and SiO₂NPs usingin vitroassays with mussel hemocytes and gill cells: Relevance of size, shape and additives

Abstract

Metal-bearing nanoparticles (NPs) possess unique physico-chemical characteristics that make them useful for an increasing number of industrial products and applications, but could also confer them a higher toxicity due to their higher reactivity compared to bulk forms of the same materials. There is a considerable interest in the use of in vitro techniques in environmentally relevant species, such as marine mussels, to evaluate NPs toxicity. In the present work, mussel hemocytes and gill cells were used to assess the potential toxic effects of Au, ZnO and SiO2 NPs with different sizes and shapes in parallel with their respective ionic and bulk forms and additives used in the NPs preparations. Cytotoxicity (neutral red and MTT assays) was screened at a wide range of concentrations, and LC50 values were calculated. Uptake of fluorescently labeled SIO2 NPs of 27 nm by hemocytes was also investigated. Au, ZnO and SiO2 NPs were less toxic than the corresponding ionic forms but more toxic than the bulk forms. ZnO NPs were the most toxic NPs tested which could be related with their capacity to release free ions. SiO2 NPs were not taken up by hemocytes and were not toxic to either hemocytes or gill cells. Size-dependent toxicity was found for Au NPs. Shape influenced the cytotoxicity of ZnO NPs. Finally, the presence of the additives Na-citrate and Ecodis P90 contributed to the toxicity of Au and ZnO NPs, respectively. As a general conclusion, solubility appears to play a key role in NPs toxicity to mussel cells.

Toxicity evaluation of boron nitride nanospheres and water-soluble boron nitride in <em>Caenorhabditis elegans</em>

“…50,51 For instance, the toxic threshold for soluble GO is lower than hydrophobic graphene in C. elegans …”

Hemocyte responses of the thick shell mussel Mytilus coruscus exposed to nano-TiO 2 and seawater acidification

“…For example, Canesi et al (2010) found that nanoscale titanium dioxide (nano-TiO 2 ) induced toxic effects on the mussel M. galloprovincialis at 1-10 mg L −1 concentration. Compared with other kinds of NPs, metal-bearing NPs, especially nano-TiO 2 , are produced at the highest amounts (Katsumiti et al, 2016). The extensive applications of nano-TiO 2 will lead to an increased environmental concentration of titanium (Hall et al, 2009) that poses a potential risk to aquatic organisms (Kaegi et al, 2008).…”

Shape-dependent antibacterial effects of non-cytotoxic gold nanoparticles

“…27,34,35 As with all NPs, AuNPs have varying degrees of cytotoxicity, which is dependent on their size, [36][37][38] surface chemistry, 35,[39][40][41] shape 34,42,43 and most importantly dosage. 18 Various trends in size-dependent cytotoxicity have been observed, most commonly showing an increased cytotoxicity for smaller sized NPs, particularly those ,5 nm.…”