Nanomaterials properties vs. biological oxidative damage: Implications for toxicity screening and exposure assessment

Biological oxidative damage (BOD) has been recognized as a key toxicity mechanism with potential as a novel global metric for nanomaterial (NM) exposure and rapid toxicity screening. A 'Ferric reducing ability of serum (FRAS)' assay, recently optimized by our group, was used to quantitate the degree of BOD induced by 19 diverse, commercially important NMs, including carbon blacks, fullerenes, carbon nanotubes, and titanium dioxide. This study investigated the relationship between several physico-chemical parameters of NMs and BOD and their relevance to exposure assessment and toxicity screening. FRAS-measured BOD strongly correlated with specific surface area and total content of select transition metals (especially Fe, Cr, Co, Mo and Mn). These two factors combined explained 93% of the BOD. The FRAS BOD potential of NMs appears to be a valid approach for screening purposes. These findings support the use of BOD as a metric for NM exposures.