Conclusion
The capability to detect nanoparticles and to distinguish particle size distribution
for unlabeled SiO2 in a sample of mammalian lung tissue has been demonstrated.
We have shown that not only can we detect unlabeled SiO2 nanoparticles
isolated from rat lung and liver tissue, but more importantly, we distinguished
between nano- and submicron-sized particles isolated from the same tissue. The
combination of enzyme digestion of tissue with particle sizing by SdFFF is a novel
approach that will greatly facilitate measurements of natural and anthropogenic
nanoparticles in laboratory toxicology studies, ecological systems, and human
populations. This work introduces a new method to characterize the size distribution of unlabeled inorganic particles in tissue which will be useful for studies focused on the neurological and cardiovascular effects of environmental and occupational exposures to an important class of engineered nanomaterials.