Efficient Elimination of Inhaled Nanoparticles from the Alveolar Region: Evidence for Interstitial Uptake and Subsequent Reentrainment onto Airways Epithelium
2007

How the Body Clears Inhaled Nanoparticles from the Lungs

Sample size: 32 publication Evidence: moderate

Author Information

Author(s): Manuela Semmler-Behnke, Shinji Takenaka, Steffanie Fertsch, Alexander Wenk, Jürgen Seitz, Paula Mayer, Günter Oberdörster, Wolfgang G. Kreyling

Primary Institution: GSF - National Research Center for Environment and Health, Institute of Inhalation Biology, Neuherberg/Munich, Germany

Hypothesis

Inhaled nanoparticles translocate from the lungs to the interstitium and are cleared via macrophages and lymphatics.

Conclusion

Nanoparticles are less phagocytized by alveolar macrophages than larger particles but are effectively removed from the lung surface into the interstitium and cleared over time.

Supporting Evidence

  • Nanoparticles were found in the bronchoalveolar lavage fluid immediately after inhalation.
  • After 3 weeks, the fraction of nanoparticles that could be lavaged decreased significantly.
  • 80% of the retained nanoparticles were translocated into the epithelium and interstitium within 3 weeks.

Takeaway

When tiny particles are breathed in, they can move into the lungs and then into the body, but the body has ways to get rid of them over time.

Methodology

The study involved healthy adult Wistar Kyoto rats that inhaled radiolabeled nanoparticles, followed by measurements of lung retention and clearance over 6 months.

Limitations

The lavage technique may not have reached the entire epithelial surface of the lungs, potentially underestimating the total nanoparticle population.

Participant Demographics

Healthy male Wistar Kyoto rats, 8-10 weeks old, approximately 250 g body weight.

Digital Object Identifier (DOI)

10.1289/ehp.9685

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