Fig. 4

Transmission electron microscopy (TEM) of SPIO labelled ASCs showing black iron inclusions (red arrows
) in the cytoplasm. a Capture of the moment of endocytosis of SPIO into a cell and formation of a membrane vesicle. b Cluster of SPIO particles within the cytoplasm one week after labelling. c Cluster of SPIO particles within the cytoplasm two weeks after SPIO labelling. (d) SPIO cluster within lysosomes (asterisk
) three weeks after labelling