Fig. 7.

Performance of reseeded scaffolds in an osteochondral defect model in vivo. Macroscopic images reveal that after six weeks the experimental defects a) appear to be empty in the control group, while b) defects filled with reseeded scaffolds feature a smooth surface. c) Cross-section through the osteochondral plug proving the filling of the defect with scaffold and new matrix. d) The histological overview sections show the scaffolds and neo-tissue within the defects and differences in distribution of collagen type II. While neo-tissue derived from bovine chondrocytes (bAC) stains regular and intensely, human chondrocytes (hAC) or ASC/TERT1-derived matrix stains strongest within the incisions (tip effect). Bone marrow invading from the subchondral space of the plug forms an intensively stained hyaline tissue all over the defect. The incision edges are more irregular than when chondrocytes or ASC/TERT1 fill the incisions. At some sites collagen type II producing cells are visible inside the scaffold close to the incision edge (arrows). n = 6.