High-content in vitro nanotoxicity assessment with enhanced throughput utilizing automated multimodal digital holographic microscopy

Nanoparticles (NP), with their unique properties, can interact with biochemical tests. Thus, for reliable and comprehensive risk assessment, it is imperative to include methods that are not affected by NP and can be applied with other biochemical techniques. Quantitative phase imaging (QPI) based on digital holographic microscopy (DHM) can be combined with optical microscopes and provides label-free access of biophysical cell properties and morphology. Recently, DHM has been demonstrated as a minimally invasive QPI tool in NP risk assessment. Here, a multimodal DHM concept for in vitro nanotoxicity assessment is presented which utilizes QPI and correlative brightfield (BF) imaging for analysis of adherent cells. In our approach living cells are automated time-lapse monitored in 96-well plates. The retrieved series of correlative BF and DHM QPI images are then evaluated by an artificial neural network-based image segmentation approach. The experimental results demonstrate multimodal bright-field and DHM QPI as a robust label-free tool for nanotoxicity assessment and high content imaging at the single cell level.