Effect of magnetic nanoparticles coating on cell proliferation and uptake

•Prepared Fe3O4 nanoparticles with different protein or polymer outer shell.•Structural, magnetic and magnetic hyperthermia studies.•No correlation between layer thickness and specific adsorption rate was confirmed.•The strongest inhibition of cell growth in polymer coated nanoparticles.•The smaller magnetic nanoparticles were less cytotoxic. Magnetic iron oxide nanoparticles (MNPs) are one of the most promising types of nanoparticles for biomedical applications, primarily in the context of nanomedicine-based diagnostics and therapy. They are used as contrast agents in magnetic resonance imaging and magnetite cell labelling. Furthermore, they are promising heating mediator in magnetic hyperthermia-based therapy, and can serve as nanocarriers in targeted gene and drug delivery as well. In biomedical applications, coating plays an important role in nanoparticle dispersion stability and biocompatibility. However, the impact of nanoparticle surface chemistry on cell uptake and proliferation has not been sufficiently investigated. The objective of this study is to prepare magnetic nanoparticles with inner magnetite core and hydrophilic outer shell of surfactant, protein and polymers that are commonly used in biomedical research. MNPs were characterized in-depth by various physicochemical methods. Magnetic hyperthermia, applied to find out the influence of MNPs coating on heating characteristics of the samples, did not show any correlation between layer thickness and specific adsorption rate. To evaluate the impact of surface chemistry on cell proliferation and internalization, the human lung adenocarcinoma epithelial (A549) cells were utilized. Substantial differences were determined in the amount of internalized MNPs and cell viability in dependence on surface coating. Our results indicate that the surface chemistry not only protects particles from agglomeration but also affect the interaction between cell and MNPs.