In vivo impact assessment of orally administered polystyrene nanoplastics: biodistribution, toxicity, and inflammatory response in mice

Abstract

To assess the in vivo impact of nanoplastics (NP) and coagulation-based purified NP (PurNP), this study analyzed for alterations in the biodistribution, toxicity and inflammatory response in ICR mice exposed to three different doses of NP (5, 25, and 50 mg/kg) and PurNP for 2 weeks. Except water consumption, which was dose-dependently and significantly increased in all NP-treated groups, most factors assessed for feeding behaviors and excretions remained constant, without any significant change. Orally administered NP was detected in the intestine, kidneys, and liver at all concentrations, although the accumulation was higher in the intestine than in the kidneys and liver. No significant alterations were detected in the levels of serum biochemical markers and histopathological structures. However, compared to the vehicle group, expressions of the inflammatory response proteins (iNOS and COX-2) and mRNA levels of the inflammatory cytokines were remarkably increased in the liver, kidneys, and intestine of NP-treated mice. A similar increase was detected in the oxidative stress responses, including ROS concentration, SOD activity, and Nrf2 expression. Furthermore, similar inflammatory responses were observed in the PurNP-treated group, as compared to the vehicle-treated group. The results presented in this study provide the first strong evidence that oral administration of NP for 2 weeks results in high accumulation in the liver, kidneys, and intestine of ICR mice, and induces severe inflammatory and oxidative stress responses. These results additionally confirm the efficacy of water purification using the tannic acid-mediated coagulation removal technique.

Keywords:

• Nanoplastics
• biodistribution
• toxicity
• inflammatory response
• oxidative stress response

Acknowledgments

The authors thank Jin Hyang Hwang, the animal technician, for directing the animal care and use at the Laboratory Animal Resources Center in Pusan National University.

Disclosure statement

There are no conflicts to declare.

Additional information

Funding

This work was supported by the BK21 FOUR Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education [F21YY8109033] and by an NRF grant funded by the Korean government (MSIP: Ministry of Science, ICT & Future Planning) [NRF-2018R1D1A1B07050070 and NRF-2021R1F1A105923711], Korea.