Labeling of macrophage cell using biocompatible magnetic nanoparticles

This work investigates the intrinsic cell labeling efficiency of the Fe₃O₄ nanoparticles prepared by a modified thermal decomposition method using nontoxic precursors and a biocompatible polymer surfactant. This method eliminates the current need for additional step of surface modification. The structural analysis reveals the highly crystalline feature of the nanoparticles, while the magnetic measurement shows their superparamagnetic behavior at room temperature. Fe₃O₄ nanoparticles were efficiently incorporated into the murine macrophage cells (RAW264.7) without visible cytotoxicity. Cell labeling efficiency was found to be over 90 as measured by magnetically activated cell sorting and physical property measurement system. Therefore, such Fe₃O₄ nanoparticles could provide a useful magnetic cell labeling tool for macrophage cells using their phagocytic/endocytic activity and further apply to the other relevant biomedical applications.