The cytotoxicity of polycationic iron oxide nanoparticles: Common endpoint assays and alternative approaches for improved understanding of cellular response mechanism

摘要

BackgroundIron oxide magnetic nanoparticles (MNP's) have an increasing number of biomedical applications. As such in vitro characterisation is essential to ensure the bio-safety of these particles. Little is known on the cellular interaction or effect on membrane integrity upon exposure to these MNPs. Here we synthesised Fe3O4 and surface coated with poly(ethylenimine) (PEI) and poly(ethylene glycol) (PEG) to achieve particles of varying surface positive charges and used them as model MNP's to evaluate the relative utility and limitations of cellular assays commonly applied for nanotoxicity assessment. An alternative approach, atomic force microscopy (AFM), was explored for the analysis of membrane structure and cell morphology upon interacting with the MNPs. The particles were tested in vitro on human SH-SY5Y, MCF-7 and U937 cell lines for reactive oxygen species (ROS) production and lipid peroxidation (LPO), LDH leakage and their overall cytotoxic effect. These results were compared with AFM topography imaging carried out on fixed cell lines.