Investigation of nanoparticle distribution formed by the rotation of the magnetic system

An even dispersion of nanoparticles onto a cell monolayer may open up new options for the gene transfer into cells and this could be a valuable achievement in the field of nanotechnology based drug delivery. Here we report on our evaluation of superparamagnetic iron oxide nanoparticle (SPION) patterning formed by magnetic arrays with unipolar NdFeB magnet arrangements and describe a rotating magnetic array as well as underlying mechanisms of the nanoparticle pattern formation. SPION pattern derived from static magnetic array represents line-like pattern, while the pattern formed by orbital magnetic array is homogenously distributed nanoparticles. Our results show that the SPION sedimentation under the time-phase varying action of magnetic field occurs with horizontal motion of nanoparticles and forms a homogenous distribution of them on the target. In the process, the amplitude of nanoparticle displacement reaches up to 0.5 µm at the magnet boundary, at the greatest linear speed tested of 60 mm/s (magnetic field gradient: 50 T/m). Application of the orbital magnetic array increases the probability of nanoparticle-cell interactions and enhances the efficiency of the gene delivery.