Change in agglomeration status and toxicokinetic fate of various nanoparticles in vivo following lung exposure in rats

Abstract

The deposition characteristics in lungs following inhalation, the potential toxic effects induced and the toxicokinetic fate including a possible translocation to other sites of the body are predominantly determined by the agglomeration status of nanoscaled primary particles. Systemic particle effects, i.e. effects on remote organs besides the respiratory tract are considered to be of relevant impact only for de-agglomerated particles with a nanoscaled aspect. Rats were exposed to various types of nanoscaled particles, i.e. titanium dioxide, carbon black and constantan. These were dispersed in physiologically compatible media, e.g. phosphate buffer, sometimes including auxiliaries. Rats were treated with aqueous nanoparticle dispersions by intratracheal instillation or were exposed to well-characterized nanoparticle aerosols. Subsequently, alterations in the particle size distribution were studied using transmission electron microscopy (TEM) as well as the bronchoalveolar lavage (BAL) technique. Based on the results in various approaches, a tendency of nanoscaled particles to form larger size agglomerates following deposition and interaction with cells or the respiratory tract is predominant. The contrary trend, i.e. the increase of particle number due to a disintegration of agglomerates seems not to be of high relevance.

Keywords::

• Nanoparticles
• agglomeration
• in vivo
• dispersion
• translocation

Acknowledgements

The authors thank B. Orthen and T. Gebel from the Federal Institute for Occupational Safety and Health (BAuA) in Dortmund, Germany for discussions on the various study designs. The final project report submitted to BAuA is available on the web (Schaudien et al., 2011).

Declaration of interest

Authors report no potential conflicts of interest. The authors alone are responsible for the content and writing of the paper. The project was funded by the Federal Institute for Occupational Safety and Health (BAuA), Dortmund, Germany.