Representative fluorescent images of PC12 cells and primary neurons. PC12 cells in (A) and (B) were stained with an anti-ß-III-tubulin antibody (in red). (A) shows control cells and (B) cells incubated with MNPs. Primary neurons in (C) and (D) were stained with an anti-MAP2 antibody (in red). (C) demonstrates control cells, (D) cells incubated with MNPs. MNPs are fluorescent green and marked with arrows. Bar represents 50 μm.