Silica and titanium dioxide nanoparticles cause pregnancy complications in mice

Abstract

The increasing use of nanomaterials has raised concerns about their potential risks to human health. Recent studies have shown that nanoparticles can cross the placenta barrier in pregnant mice and cause neurotoxicity in their offspring, but a more detailed understanding of the effects of nanoparticles on pregnant animals remains elusive. Here, we show that silica and titanium dioxide nanoparticles with diameters of 70 nm and 35 nm, respectively, can cause pregnancy complications when injected intravenously into pregnant mice. The silica and titanium dioxide nanoparticles were found in the placenta, fetal liver and fetal brain. Mice treated with these nanoparticles had smaller uteri and smaller fetuses than untreated controls. Fullerene molecules and larger (300 and 1,000 nm) silica particles did not induce these complications. These detrimental effects are linked to structural and functional abnormalities in the placenta on the maternal side, and are abolished when the surfaces of the silica nanoparticles are modified with carboxyl and amine groups.

Transport of Nanoparticles through the Placental Barrier

“…The reports indicate that NP transport highly depends on NP size. The threshold of NP penetration across the barrier was found to be between 143-300 nm for silica NP in mice (Yamashita et al 2011) and between 80-240 nm for polystyrene NP in humans (Wick et al 2010). The size-dependent NP penetration was also determined for other barriers, e.g.…”

“…A recent study of another group also reported pregnancy complications in mice induced by NP (Yamashita et al 2011). The authors examined the distribution and fetal toxicity of differently sized silica and titanium oxide (TiO 2 ) NP.…”

“…Therefore, comprehensive knowledge about possible physiological effects of NP is crucial independently on whether NP exposure is intended or not. Some nanomaterials such as titanium dioxide (TiO 2 ) or silica nanoparticles have been already used in cosmetics, food, electronics and medicine (Yamashita et al 2011). The growing number of commercial products and the expansion of NP application areas raise concerns about NP accumulation, long-term retention in an organism and subsequent toxic effects.…”

“…Humans are more sensitive to toxic materials in prenatal stages than in mature age and scientific studies have shown that chemicals in maternal surroundings (air, food, water) can induce pregnancy complications and embryotoxicity (Yamashita et al 2011). The potential fetal toxicity first of all depends on the passage of particles from the maternal organism which is mainly determined by the placental barrier in the case of mammals.…”

Human health hazards of persistent inorganic and carbon nanoparticles

“…Potential effects on the lungs include damage to membranes, cytotoxicity, genotoxicity, apoptosis (induced programmed cell death), necrosis (cell death due to toxic interference with vital cell functions), inflammation, fibrosis, and cancer [1-3, and references therein]. Inhaled nanoparticles may penetrate the alveolar-capillary barrier between the respiratory and circulatory system, and thus be translocated from the lungs [2,3,[30][31][32][33][34][35][36][37][38][39][40][41][42], and references therein]. When the nanoparticles translocate to the circulatory system, other organs may also be affected [1-3, 15, 16, 30-32, 39-42].…”