Toxicological Evaluation of SiO2 Nanoparticles by Zebrafish Embryo Toxicity Test

Abstract

As the use of nanoparticles (NPs) is increasing, the potential toxicity and behavior of NPs in living systems need to be better understood. Our goal was to evaluate the developmental toxicity and bio-distribution of two different sizes of fluorescently-labeled SiO2 NPs, 25 and 115 nm, with neutral surface charge or with different surface functionalization, rendering them positively or negatively charged, in order to predict the effect of NPs in humans. We performed a zebrafish embryo toxicity test (ZFET) by exposing the embryos to SiO2 NPs starting from six hours post fertilization (hpf). Survival rate, hatching time, and gross morphological changes were assessed at 12, 24, 36, 48, 60, and 72 hpf. We evaluated the effect of NPs on angiogenesis by counting the number of sub-intestinal vessels between the second and seventh intersegmental vessels and gene expression analysis of vascular endothelial growth factor (VEGF) and VEGF receptors at 72 hpf. SiO2 NPs did not show any adverse effects on survival rate, hatching time, gross morphology, or physiological angiogenesis. We found that SiO2 NPs were trapped by the chorion up until to the hatching stage. After chemical removal of the chorion (dechorionation), positively surface-charged SiO2 NPs (25 nm) significantly reduced the survival rate of the fish compared to the control group. These results indicate that zebrafish chorion acts as a physical barrier against SiO2 NPs, and removing the chorions in ZFET might be necessary for evaluation of toxicity of NPs.

Characterization and Biotechnological Potential of Intracellular Polyhydroxybutyrate by Stigeoclonium sp. B23 Using Cassava Peel as Carbon Source

“…Five to 15% of zebrafish embryos did not show detachment of their tails and lacked a visible heartbeat. No differences in toxicity parameters were observed for PHB nanoparticles between the chorion-protected life stages before 48 h of development and hatched embryos until 96 h. Such a protective role of the chorion and toxicity differences is often observed for nanoparticles, e.g., described for SiO 2 nanoparticles [ 56 ]. In contrast to the observed toxicity on zebrafish embryos, PHB is described as a non-toxic biopolymer [ 57 ], and PHB films such as poly(3-hydroxyoctanoate) (PHO) were not toxic on L929 cells and not pro-inflammatory [ 58 ].…”

Induced pluripotent stem cell-derived vascular networks to screen nano–bio interactions

“…58,59 Therefore, in the current work, zebrafish embryos were used to validate the toxicity profiles of the NP library evaluated in the in vitro tests. Because some NPs are trapped by the chorion of zebrafish, 60 we have removed it to perform the screening. Our results showed that 18 NP formulations had an impact in the angiogenesis of the intersegmental vessels of zebrafish embryos.…”

Thymol‐Loaded Biogenic Silica Nanoparticles in an Aquatic Environment: The Impact of Particle Aggregation on Ecotoxicity

“…Also, BSiO 2 #THY induced the same significant sublethal effects of thymol (pericardial edema, delayed yolk sac absorption, and delayed hatching) after 96 h of exposure (Figure 3 and Table 1). It is worth mentioning that the early stages of the zebrafish are protected by 2 outer protein membranes of 10 μm thickness (chorion and inner perivitelline membrane; Scholz et al 2008; Kais et al 2013; Li et al 2014; Vranic et al 2019), but the chorion contains pores with an average diameter of 0.5 to 0.7 μm, which could allow the passage of solute such as NPs (Ali et al 2017). In the present study, the BSiO 2 carrier did not aggregate and precipitate in the zebrafish medium, as occurred in the A. salina medium (Figure 5).…”