Body distribution of SiO₂–Fe₃O₄ core-shell nanoparticles after intravenous injection and intratracheal instillation

Abstract

Nano-silicon dioxide (SiO₂) is used nowadays in several biomedical applications such as drug delivery and cancer therapy, and is produced on an industrial scale as additive to paints and coatings, cosmetics and food. Data regarding the long-term biokinetics of SiO₂ engineered nanoparticles (ENPs) is lacking. In this study, the whole-body biodistribution of SiO₂ core-shell ENPs containing a paramagnetic core of Fe₃O₄ was investigated after a single exposure via intravenous injection or intratracheal instillation in mice. The distribution and accumulation in different organs was evaluated for a period of 84 days using several techniques, including magnetic resonance imaging, inductively coupled plasma mass spectrometry, X-ray fluorescence and X-ray absorption near edge structure spectroscopy. We demonstrated that intravenously administered SiO₂ ENPs mainly accumulate in the liver, and are retained in this tissue for over 84 days. After intratracheal instillation, an almost complete particle clearance from the lung was seen after 84 days with distribution to spleen and kidney. Furthermore, we have strong evidence that the ENPs retain their original core-shell structure during the whole observation period. This work gives an insight into the whole-body biodistribution of SiO₂ ENPs and will provide guidance for further toxicity studies.

• Body distribution
• ICP-MS
• MRI
• silicon dioxide
• XRF

Acknowledgements

We thank Kristin Coorevits for technical assistance with ICP-MS analyses. We acknowledge the European Synchrotron Radiation Facility synchrotron for provision of beamtime (ID21 beamline) and Hiram Castillo for his useful help in the preparation of cryomicrotome thin sections for XRF analyses. S.B. thanks the FWO-Research Foundation Flanders for a PhD fellowship.

Declaration of interest

This work was supported by the Seventh Framework Program of the European Commission NanoHouse-Grant (Agreement No. 207816) and by Hercules fund AKUL/11/10. There is no conflict of interest.

Supplementary material available online