FIG. 5.

Histological analysis of ectopic NP tissue formation in vivo. Four weeks after subcutaneous implantation of either the NF or the SW constructs, the tissue sections were stained with safranin-O for glycosaminoglycan (GAG) (A, B), Masson's trichrome for total collagen (C, D), and immunohistochemically stained for type I/II collagen (E–H). Abundant GAG and type II collagen, while little type I collagen, were found in engineered tissue using the NF scaffold. In contrast, lower contents of GAG and type II collagen indicated poor NP formation from the SW scaffold group. At the same time, abundant deposition of type I collagen on the SW scaffold indicated fibrous tissue invasion in the SW scaffold group. Color images available online at www.liebertpub.com/tea