Honeycomb-shaped magnetic multilayer thin films for cell trapping

Abstract

Honeycomb-shaped magnetic thin films with domain wall (DW) pinning geometry are designed to actively trap magnetically labeled cells. After an initial in-plane magnetic field (H_initial) is applied and later reduced to zero, the resultant magnetization became locally aligned. Human hepatocellular liver carcinoma cell line (HepG2) stably expresses green fluorescent protein (GFP) and is magnetically labeled with superparamagnetic magnetic nanoparticles (MNPs). Prussian blue stain and single cell magnetophoresis are performed to evaluate the internalization of the MNPs. Magnetically labeled cells are then trapped by the stray fields of head-to-head DWs (HH DWs) or tail-to-tail DWs (TT DWs). After co-culturing with magnetic structure, HepG2 cells stretched out and showed filopodia-like protrusions to make contact with adjacent cells.