Current limitations and challenges of nanoparticle toxicity assessments

Due to the increasing concerns on the potential risk of manufactured nanomaterials. understanding their toxicity mechanism, environmental fates, and impacts on human health and ecosystems became one of the urgent scientific issues to be addressed. Here, based on our recent studies on the P25 TiO₂ (Evonik GmbH) dispersion, current limitations and challenges in nanoparticle toxicity assessments will be discussed. Particularly, among the many issues of nanoparticle toxicology, we will focus on the issues of the appropriate dosing metrics of NPs and effects of various physicochemical properties on the dosing metrics as well as the limitations of current cytotoxicity assay protocols for the assessment of NP toxicity.