Application and validation of an impedance-based real time cell analyzer to measure the toxicity of nanoparticles impacting human bronchial epithelial cells

Nanomaterials are increasingly used in a variety of industrial processes and consumer products. There are growing concerns about the potential impacts for public health and environment of engineered nanoparticles. The aim of this work was to evaluate a novel impedance-based real time cell analyzer (RTCA) as a high-throughput method for screening the cytotoxicity of nanoparticles and to validate the RTCA results using a conventional cytotoxicity test (MTT). A collection of 11 inorganic nanomaterials (Ag⁰, Al₂O ₃, CeO₂, Fe⁰, Fe₂O₃, HfO₂, Mn₂O₃, SiO₂, TiO₂, ZnO, and ZrO₂) were tested for potential cytotoxicity to a human bronchial epithelial cell, 16HBE14o-. The data collected by the RTCA system was compared to results obtained using a more traditional methyl tetrazolium (MTT) cytotoxicity assay at selected time points following application of nanomaterials. The most toxic nanoparticles were ZnO, Mn₂O ₃ and Ag⁰, with 50% response at concentrations lower than 75 mg/L. There was a good correlation in cytotoxicity measurements between the two methods; however, the RTCA method maintained a distinct advantage in continually following cytotoxicity over time. The results demonstrate the potential and validity of the impedance-based RTCA technique to rapidly screen for nanoparticle toxicity.