Synchrotron radiation X-ray fluorescence analysis of biodistribution and pulmonary toxicity of nanoscale titanium dioxide in mice.

Using synchrotron radiation X-ray fluorescence (SRXRF), we have examined the biodistribution and pulmonary toxicity of nanoscale titanium dioxide (nanoTiO2) in mice at the elemental level. Notably, nanoTiO2 particles were mainly retained in lungs after intratracheal instillation, slowly cleared and were still present at 3 months. Different methods of intratracheal instillation influenced the clearance of nanoTiO2 from lungs. NanoTiO2 interfered with the natural distribution of K, Ca, Fe, Cu and Zn in lungs. We have thus demonstrated that SRXRF provides an effective approach to investigate the distribution of metal nanomaterials and native metal elements in tissues and organs, which offers new opportunities for revealing nanotoxic mechanisms of nanomaterials.