PROCESSING OF METAL OXIDE NANOPARTICLES IN SIMULATED ENVIRONMENTS: IMPLICATIONS FOR FATE AND PULMONARY TOXICITY
John M. Pettibone, Vicki H. Grassian, Peter Thorne, Patrick O’Shaughnessy, and Andrea Adamcakova-Dodd
The manufacturing of metal and metal oxide nanomaterials for commercial products continues to grow because of their superior properties over their bulk counterparts. The continual growth of engineered nanoparticles in commercial and industrial applications has lead to the inevitable release into natural environments (e.g. soil, water or air) through production, distribution and use. The engineered nanomaterials possess unique physicochemical properties due to their size, which makes it reasonable to surmise that their processing in different environments will change concomitantly with their toxicity. Nanomaterials that pose significant risks associated with ecosystem sustainability and ultimately human health need to be modified or eliminated prior to market introduction.
Thorough characterization of the nanomaterials was necessary for more accurate descriptions of the physicochemical properties which included bulk and surface measurements as well as phase effects. Surface interactions drive the processing in biological or environmental conditions and detailed examination at the solid interfaces was conducted with FTIR and XPS techniques. We examined the surface properties of metal and metal oxide nanoparticles in both simulated biological (ALF, Gamble’s) and natural environments and made comparisons to larger particles. The full characterization of the metal (oxide) nanoparticles allowed for the correlation of nanoparticle properties to toxicological effects in mice models and size specific product formation and/or degradation in simulated natural aqueous environments.