Attribute-Driven Maternal-Fetal Transfer of Atmospheric Magnetite Nanoparticles Revealed by Single-Particle Analysis

Area of Science:

• Environmental Health
• Toxicology
• Nanotechnology

Background:

• Atmospheric magnetite nanoparticles (MNPs) are a component of PM2.5 with understudied health impacts.
• Potential systemic and developmental effects of MNPs, especially during pregnancy, are a growing concern.

Purpose of the Study:

• To investigate the biodistribution and maternal-fetal transfer of atmospheric MNPs.
• To characterize MNP accumulation in maternal and fetal organs following inhalation exposure.

Main Methods:

• Whole-body inhalation exposure model in pregnant C57BL/6 mice.
• Magnetic extraction, high-resolution Transmission Electron Microscopy (TEM), and single-particle mass spectrometry for MNP characterization.
• Quantitative analysis of MNP burden in maternal and fetal tissues.

Main Results:

• MNPs accumulated significantly in maternal serum, liver, spleen, placenta, and lung (93% of total burden).
• Approximately 0.7% of MNPs transferred to the fetus, with over 60% localized in the fetal liver.
• Fine-sized MNPs, enriched with toxic metals (Zn, Pb), were found in fetal heart and brain.
• Particle size and elemental composition were key factors in systemic transport and placental transfer.

Conclusions:

• Inhaled atmospheric MNPs can cross the placental barrier and accumulate in fetal organs.
• These findings underscore the risks of early-life exposure to MNPs.
• Particle-specific air quality standards are necessary to mitigate MNP-related health risks.