Physiological and Behavioral Effects of SiO2 Nanoparticle Ingestion on Daphnia magna

Abstract

The increasingly widespread use of engineered nanoparticles in medical, industrial, and food applications has raised concerns regarding their potential toxicity to humans and the environment. Silicon dioxide nanoparticles (SiO2 NPs), which have relatively low direct toxicity, have been increasingly applied in both consumer products and biomedical applications, leading to significantly higher exposure for humans and the environment. We carried out a toxicity assessment of SiO2 NPs using the common water flea D. magna by focusing on physiological and behavioral indicators such as heart rate, swimming performance, and growth. Exposure to SiO2 NPs did not produce acute or chronic toxicity at limited concentrations (<100 μg/mL), but did have statistically significant negative effects on heart rate, swimming distance, and body size. The use of fluorescein isothiocyanate in a silica matrix allowed the tracing and visualization of clear SiO2 NP accumulation in D. magna, which was confirmed by ICP-MS. Although exposure to SiO2 NPs seemed to affect cardiac and swimming performance, such end-point experiments may be insufficient to fully understand the toxicity of these nanoparticles. However, the physiological and behavioral changes shown here suggest potential adverse effects on the aquatic environment by substances previously considered nontoxic.

Can Pharmaceutical Excipients Threaten the Aquatic Environment? A Risk Assessment Based on the Microtox® Biotest

“…The authors of the study demonstrated no acute toxicity of the tested silica at concentrations up to 100 mg/L. However, significant physiological and behavioral changes were observed in adults and young D. magna animals, such as changes in swimming efficiency, individual size, and reproductive impairment; these factors supported the hypothesis that SiO 2 had a negative effect on D. magna [ 40 ]. Other authors indicated that both amorphous and crystalline forms of SiO 2 could lead to lymph-node fibrosis in rats [ 41 ].…”

Developmental effects on Daphnia magna induced by titanium dioxide and iron oxide mixtures

“…After stabilisation, the swimming distance was monitored every minute for 10 min, using a millimeter paper. The latter method was modified from the protocol used by Kim et al (2021).…”

“…The heart rate was recorded as a video file for one min using an integrated PC light microscope at 4× grossing (Optika microscopes, Italy). The heart rate was manually counted using a low-speed reading (×0.3) and repeated three times, with the mean values of each sample used for comparison (Kim et al 2021).…”

In Situ and after Synthesis of Magnetic Nanoarchitectures Grown onto Zeolite Type 5A/CTAB Frameworks and Their Ecotoxicological Properties

“…In general, the main results have suggested that the D. magna reproduction decreased in a concentration–response pattern in all generations tested for Ag NPs, whereas TiO 2 NPs had no effect in the reproduction rate . It was also shown that SiO 2 NPs may or may not cause alterations in the reproduction rate depending on the concentration and size of NPs. − Up to now, we only know the work done by Tamanaha-Vegas et al using a γ-Fe 2 O 3 nanocomposite to study the effect of the γ-Fe 2 O 3 NPs on the reproduction rate of the D. magna.…”