Targeted penetration of MCF-7 cells using iron-oxide nanoparticles in vitro

We achieve selective penetration of MCF-7 breast cancer cells using iron-oxide nanoparticles without causing a permanent damage to the membrane and without any effect on the cell morphology. The nanoparticles are controllably pulled towards the cells under the influence of the magnetic field gradients. First, the nanoparticles are fabricated and their magnetic dipole moment is characterized to be 7.8×10-8 A.m2, at magnetic field of 60 mT and mass of 1.80×10-9 kg. This characterization is done by measuring the magnetic force exerted on their dipole moment under the influence of controlled magnetic field gradient. Second, a magnetic-based control system is designed and used to achieve selective targeting of the cells under microscopic guidance. We find that the magnetic control achieves immediate uptake of nanoparticles in the MCF-7 cells without incubation for relatively long time, using magnetic force less than 51 nN. In addition, a microforce sensing probe is used to characterize the impendence of the cells to limit the exerted magnetic force during penetration and to avoid causing damage to the membrane. We find that a single cell can overcome penetration force in excess of 13.3 μN.