Fig. 6.

Images of vascular immunohistochemical examinations of nitrided iron scaffold after 7 years implantation in porcine coronary artery. (A & B) Elastic fiber staining analysis showed that a small amount of the original inner and outer elastic plates of blood vessels remained on the vessel wall, and there was no continuous inner and outer elastic plates in the scaffold segment of the blood vessel; (C & D) Masson tricolor staining found a large number of possible smooth muscle cells (red) but only small quantity of collagen fibers (green) in neointima, which was similar to the normal vascular media; (E & F) Further immunohistochemical staining (SMA staining) confirmed that the red in Figures C and D were the smooth muscle cells and a large amount of collagen in the neointima smooth muscle cells, they were the important part of the vascular media; (G & H) On the surface of the vessel lumens, a layer of functionally mature endothelial cells could also be seen (CD31 staining). Those results showed structurally complete intima, media and adventitia were restored. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)