Cell Trapping by Local Magnetic Force Using Sinewave Magnetic Structure

A sine wave magnetic structure with domain wall (DW) pinning geometry is designed to actively trap magnetically labeled cells. After an initial in-plane magnetic field (H_initial) is applied and later reduced to zero, and the resultant magnetization became locally aligned. Primary mouse embryonic fibroblasts are magnetically labeled by internalizing magnetic nanoparticles (MNPs). Prussian blue stain and single-cell magnetophoresis are performed to evaluate the internalization of the MNPs. The magnetically labeled cells are then trapped by the stray fields of the head-to-head DWs or the tail-to-tail DWs. The magnetic attraction force is estimated to be 0.2-1.3 pN, while the corresponding magnetic gradient is estimated to be 1.64 to 2.1 T/m.