Modeling better in vitro models for the prediction of nanoparticle toxicity: a review

Exposure to nanoparticles (NPs) is plausible in real life due to ambient particulate exposure or development of nanotechnologies, hence the evaluation of NP toxicity as well as mechanism-based studies are necessary. The in vitro models allow rapid testing of NP toxicity, but it is required that the developed in vitro models are reliable to reflect the toxicity of NPs. In this review, we discussed the principles to model better in vitro models to predict the toxicity of NPs based on our own experiences and works of literature. We suggested that in vitro nanotoxicological studies should consider (1) using normal cells because the commonly used cancer cell lines might not reflect the toxicity of NPs to normal tissues; (2) the possible influence of biological molecules to reflect the toxicity of NPs in a biological microenvironment; (3) the influence of pathophysiological conditions to mimic the responses of NPs under different in vivo conditions; and (4) developing advanced tissue-based models to reflect the responses of tissues/organs to NPs. It is our hope that this review may provide useful information for the future design of in vitro nanotoxicological studies.