TEM images. TEM images of C6 glioma cells that were incubated with the acetylated APTS-coated Fe3O4 NPs at a concentration of 25 μg/mL for 24 h (a) and C6 glioma cells that were treated with PBS buffer (b). The acetylated APTS-coated Fe3O4 NPs in the endosomes are visible as electron-dense nanoparticles and are indicated by black arrows. The white arrows indicate the normal endosome without NPs.
Li et al. Nanoscale Research Letters 2014 9:304 doi:10.1186/1556-276X-9-304