Fig. 2

a Natural coral scaffolds (8 mm in diameter and 2 mm in height). b T-MSCs and coral scaffold complex. Fluorescence microscope examination showed the attachment of T-MSCs on the coral scaffold. Nuclei were visualized by Hoechst 33342 staining. c Cell-seeding efficacy and proliferation on coral scaffolds (n = 4). Each scaffold was seeded with 2 × 10⁶ cells which were i chondrocytes, ii 1:1 mixture of MSCs and chondrocytes, iii MSCs, and iv T-MSCs. The initial 2 × 10⁶ cells before seeding from each group acted as control. There were no significant differences among groups (P > 0.05). d Representative macroscopic pictures of the cell–scaffold composites (i chondrocyte–coral composites, ii chondrocytes and MSCs coseeded into natural coral scaffolds in ratio of 1:1, iii MSC–coral composites, and iv T-MSC–coral composites) removed from animals after 1 month and 2 months (Color figure online)