Analysis of Nano-Cytotoxicity from an Interlaboratory Dose-Response Experiment

• Activity Number: 341
• Type: Topic Contributed
• Date/Time: Tuesday, August 11, 2015 : 10:30 AM to 12:20 PM
• Sponsor: W.J. Youden Award in Interlaboratory Testing
• Author(s): Blaza Toman* and Matthias Rösslein and John Elliott
• Companies: NIST and EMPA and NIST
• Keywords: interlaboratory study ; logistic model ; dose response ; experimental design ; nano-toxicity ; hierarchical model

Abstract

Nanomaterials used in many commercial applications such as textiles and medicine may have unintended harmful effects on various biological systems and it is important to be able to accurately assess their toxicity. A common assay for cytotoxicity is the MTS assay. This talk will describe an assay plate design for a dose response experiment which makes it possible to assess the validity of the results and quantify uncertainty in the toxicity measurements. This design was recently used in an interlaboratory comparison of 5 laboratories. The interlaboratory study design measured the effects of cell line source, serum and medium differences as well as laboratory effects. The talk will describe the uncertainty analysis of the toxicity data (proportion of live cells) from the interlaboratory study. Each measurement is a dose response curve estimated by a logistic regression model via Markov Chain Monte Carlo methods. The curves are characterized using three parameters and are arranged in a Bayesian hierarchical model. The talk will describe in detail how uncertainty from the various sources is accounted for in the final result.