Histological and gene expression analysis of the extent of in vivo repair after 14 days using silk and silk/collagen scaffolds in a rabbit model of MCL transection . (A, B) H&E staining showed relatively unorganized matrix formation but a high cell density in silk/collagen scaffolds than silk alone. (C, D) Masson's trichrome staining revealed the beginnings of collagen fiber formation (indicated by blue areas), and more collagen deposition in the silk/collagen scaffold group. (E) Total collagen content was reduced in the silk/collagen group (S + C), but, as detected by RT-PCR shown in (F, G), this could have been due to a reduction in the expression of collagen type III, an alternative collagen type for the ligamentous phenotype than collagen type I and decorin, both of which showing higher level of expression in the silk/collagen scaffold group. Reproduced with permission from Elsevier B.V.