In vivo intrinsic atomic interaction infer molecular eco-toxicity of industrial TiO2 nanoparticles via oxidative stress channelized steatosis and apoptosis in Paramecium caudatum.

The ecotoxicological effect of after-usage released TiO2 nanoparticles in aquatic resources has been a major concern owing to their production and utilization in different applications. Addressing the issue, this study investigates the detailed in vivo molecular toxicity of TiO2 nanoparticles with Paramecium caudatum. TiO2 nanoparticles were synthesized at a lab scale using high energy ball milling technique; characterized for their physicochemical properties and investigated for their ecotoxicological impact on oxidative stress, steatosis, and apoptosis of cells through different biochemical analysis, flow cytometry, and fluorescent microscopy. TiO2 nanoparticles; TiO2 (N15); of size 36 ± 12 nm were synthesized with a zeta potential of - 20.2 ± 8.8 mV and bandgap of 4.6 ± 0.3 eV and exhibited a blue shift in UV-spectrum. Compared to the Bulk TiO2, the TiO2 (N15) exhibited higher cytotoxicity with a 24 h LC50 of 202.4 µg/ml with P. Caudatum. The mechanism was elucidated as the size and charge-dependent internalization of nanoparticles leading to abnormal physiological metabolism in oxidative stress, steatosis, and apoptosis because of their influential effect on the activity of metabolic proteins like SOD, GSH, MDA, and catalase. The study emphasized the controlled usage TiO2 nanoparticles in daily activity with a concern for ecological and biomedical aspects.