Biological Cell Manipulation by Magnetic Nanoparticles

We report a manipulation of biological cells (erythrocytes) by magnetite (Fe₃O₄) nanoparticles in the presence of magnetic field. The experiment was accomplished on the top of the micro-electromagnet consisting of two magnetic field generating contours. An electric current flowing through the contour(s) produces a non-uniform magnetic field, which is about 1.4mT/1µm at 100mA current in the vicinity of the current-carrying wire. It makes magnetic nanoparticles to move towards the magnetic energy minima. In turn, magnetic nanoparticles drag biological cells in the same direction. We present experimental data showing cell manipulation by controlling the electric currents. This technique allows us to capture and to move cells located in the vicinity (10-20 microns) of the current-carrying wires. One of the most interesting results shows a periodic motion of erythrocytes between the two conducting contours, which frequency is controlled by the electric circuit. The obtained results demonstrate the feasibility of non-destructive cell manipulation by magnetic nanoparticles with micrometer-scale precision.