Fig. 9

Histology of silk hydrogel implants. The gel implant samples at the hind limb subcutaneous at day 4, 12, 16, 18 and 20 (a–e) subjected to H&E staining and immunohistochemical staining at day 20 (f). At day 4, gel implants showed few cells attachment or tissue formation (a). A little of fibrous connective tissue had formed on the gel surface at day 12 (b), and micro vessels could be seen at day 16 and 18 (c, d). At day 20, a capsule membrane mainly consisting of blood vessels and fibrous connective tissue had formed on the gel surface or in the gel (e), and endothelial cell surface marker was expressed (f); *residual silk gel implants