Enhancement of neurite outgrowth in PC12 cells by iron oxide nanoparticles.

Despite the many potential therapeutic applications of iron oxide nanoparticle such as its use as an imaging and targeting tool, its biological effects have not yet been extensively characterized. Herein, we report that iron oxide nanoparticles taken up by PC12 cells can enhance neurite outgrowth. PC12 cells exposed to both iron oxide nanoparticles and nerve growth factor (NGF) synergistically increased the efficiency of neurite outgrowth in a dose-dependent manner. This may have resulted from the activation of cell adhesion molecules that are associated with cell-matrix interactions through iron. Immunoblotting assays also revealed that both neural specific marker protein and cell adhesion protein expression were upregulated by iron oxide nanoparticles compared with non-treated cells via activation of the mitogen-activated protein kinase (MAPK) signaling pathway. Our findings point to the possibility that iron oxide nanoparticles can affect cell-substrate interactions and regulate cell behaviors, which provides clinical insights into potential neurologic and therapeutic applications of iron oxide nanoparticles.