Cerium oxide nanoparticles in vivo distribution and transformation behavior mediate intestinal transit function

Area of Science:

• Environmental Science
• Toxicology
• Nanotechnology

Background:

• Cerium oxide nanoparticles (CeO2 NPs) exposure is possible through food chains.
• The impact of continuous CeO2 NP ingestion on the intestinal microecosystem is not well understood.
• Investigating CeO2 NP distribution and physiological effects in vivo is crucial.

Purpose of the Study:

• To investigate the in vivo distribution of CeO2 NPs after continuous ingestion.
• To elucidate the biochemical mechanisms, particularly Ce3+/Ce4+ electron conversion, involved in ROS elimination.
• To assess the impact of CeO2 NPs on intestinal physiological function and microbial co-involvement.

Main Methods:

• Mice were administered CeO2 NPs (10 mg/kg·bw/day) for 28 days.
• Tissue distribution analysis was performed to quantify NP accumulation.
• Biochemical assays measured reactive oxygen species (ROS) levels and redox processes.

Main Results:

• CeO2 NPs were primarily excreted in feces (51.49%), with remaining levels found in all tissues, notably stomach (36.78%) and intestine (4.44%).
• CeO2 NPs accumulated in the intestine, participating in redox processes and alleviating transport function disruption.
• Ce3+/Ce4+ electron transfer significantly reduced hydrogen peroxide (H2O2) by 32.92% and mitigated microbial ROS production.

Conclusions:

• CeO2 NP ingestion leads to excretion and accumulation in digestive tissues.
• The Ce3+/Ce4+ electron transfer mechanism is key in reducing intestinal ROS and preserving transport capacity.
• This study provides insights into CeO2 NP physiological fate and redox effects, informing human health risk assessments.