Toxic effects of TiO2 NPs in the blood-milk barrier of the maternal dams and growth of offspring

Titanium dioxide nanoparticles (TiO 2 NPs) are amongst the most frequently used nanomaterial in everyday consumer products, and their widespread applications have raised concerns of the consequent deleterious effects on human health, particularly to vulnerable populations, such as lactating females remains elusive. Therefore, this study was initiated to investigate the detrimental effects and toxic mechanisms induced by TiO 2 NPs in maternal dams and offspring during the lactation period. Dams were randomly divided into three groups. The water (Control; Group I) and TiO 2 NPs (100 mg/kg; Group II) were orally administered from postnatal day 1–20, respectively. The results indicated that TiO 2 NPs could cause toxicity in the dams, such as pathological damages to mammary gland tissues. The excessive accumulation of TiO 2 NPs could induce oxidative stress in the mammary gland, leading to the dysfunctional blood-milk barrier; besides, TiO 2 NPs could also be transferred to offspring via breastfeeding, causing abnormal development of infant. We further accessed the possible underlying molecular mechanism; for this, we orally administered TiO 2 NPs with vitamin E (100 mg/kg; Group III). The results revealed that toxicity induced by TiO 2 NPs was rescued. Collectively, this study presented the deleterious pathological effects of oral exposure to TiO 2 NPs in the mammary gland tissues and blood-milk barrier via the production of reactive oxygen species (ROS) in dams and developmental concerns in offspring. However, the administration of VE could mitigate the toxic effects induced by the TiO 2 NPs.