Figure 7.

In vivo transplantation of TEC to rat osteochondral defects. (a–f) Macroappearance and Safranin-O staining (Saf-O) for each group at 1 month and 2 months. Inset boxes in the upper panels are magnified in lower panels with the same frame. Representative data are shown (N = 5 knees for the empty group, N = 6 knees for the hBM-TEC group, and N = 7 knees for the iNCMSC-TEC group at each endpoint). Histological assessments were conducted at two different points as shown in the macroimages (“P” represents “proximal section” and “D” presents “distal section”). Scale bars = 1 mm (macroimage), 500 μm (upper panels of Saf-O), and 200 μm (lower panels of Saf-O). (g, h) Human vimentin immunostaining of the iNCMSC-TEC group at 1 month and 2 months. Scale bars = 500 μm. (i) Macroscopic score based on their gross appearance [57]. Averaged score with standard deviation is shown. ^∗P < 0.05 by the Steel-Dwass test. (j) Histological grading by the O'Driscoll scoring system based on Saf-O staining using two specimens (“P” and “D”) per each knee. Data are expressed as the mean ± SD for each group. ^∗P < 0.05 by the Steel-Dwass test. (k) The quantitation of transplanted iNCMSCs remaining at the implantation site was calculated from their hVimentin-DAB positive area. Data are shown as box-and-whisker plots and dot plots. Abbreviations: TEC: Tissue-engineered construct; hBM: Human bone marrow mesenchymal stem cell; iNCMSC: Induced neural crest-derived mesenchymal stem cells.