Quartz crystal microbalance monitoring of intervention of doxorubicin-loaded core–shell magnetic silica nanospheres on human breast cancer cells (MCF-7)

We prepare core–shell type magnetic silica nanospheres (Fe3O4@SiO2) as drug carriers for cellular delivery of the widely used anticancer drug doxorubicin (DOX). The cytotoxicity of doxorubicin-loaded magnetic silica composite (DOX-Fe3O4@SiO2) on human breast cancer cells (MCF-7) are studied by dynamic quartz crystal microbalance (QCM) monitoring, cyclic voltammetry (CV) characterization, 3-(4,5-dimethylthizaol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and optical microscopic inspections, and agreeable conclusions are drawn from various methods. We find that the DOX-Fe3O4@SiO2 are able to induce cell death in a dose-dependent way and exhibit higher cytotoxicity under external magnetic field in comparison with the free DOX, suggesting the potential of the Fe3O4@SiO2 for targeting drug-delivery. The QCM sensor-based in situ/process monitoring in combination with ex situ/static analyses based on CV, MTT and optical microscopic inspections provides a reliable and informative experimental platform for investigating incubation of cells and interventions from exogenous substances.