Figure 4

Histological examination of rat corpus cavernosum. At the end of each of the in vivo MR imaging experiments, SPION particles (blue dots) are clearly visible with Prussian blue staining (arrows). (A) At day 1 after transplantation. (B) At 1 week after transplantation. (C) At 2 weeks after transplantation. (D) At 4 weeks after transplantation. H&E staining was carried out before (E) and 4 weeks after transplantation (F). Lack of cellular infiltrations indicates no negative immune response by rats. Scale bars = 20 µm.