The use of pulsed magnetic fields to increase the uptake of iron oxide nanoparticles by living cells

Remote control of the interaction of magnetic nanoparticles with cells is fundamental to any potential downstream applications of magnetic nanoparticles such as gene and drug delivery vehicles and magnetic cell labeling. Thus, approaches based on the application of external magnetic fields to increase the efficiency of magnetic cell labeling are desirable. Here, we report a simple approach that enhances magnetic cell labeling using pulsed magnetic fields. The rate of uptake of superparamagnetic iron oxide nanoparticles (SPIONs) and transport across the cell membrane were enhanced upon application of a high intensity (7 T) short pulse width (∼15 μs) magnetic field. We present a quantitative analysis and mechanistic explanation of how a pulsed magnetic field influences the uptake of SPIONs by cells. Our findings offer insights into the mechanics of how pulsed magnetic fields can be effectively used to optimize magnetic cell labeling, which can provide a basis for better controlled biomedical applications of SPIONs.