Fig 1.
A schematic illustration of the experimental design for articular cartilage repair.
Fig 2.
Overview of scaffold fabrication and characterization.
Schematic of the temperature control system used to fabricate the oriented scaffold (A); macroscopic views of the oriented (B) and random scaffolds (G), oriented (C) and random (H) scaffolds stained dark-blue after cross-linking with genipin; SEM micrographs of the microtubules in the oriented scaffold (E, F) and the sponge-like pores in the random scaffold (J, K); Scaffold auto-fluorescence (red) after being cross-linked with genipin (D, I). TH, high temperature; TL, low temperature; T0, no difference in temperatures between the top and bottom of the mould.
Fig 3.
Cell distribution and viability within the scaffolds.
Distribution and morphology of the differentiated BMSCs cultured on the oriented (A, B) and the random (C, D) scaffolds; Live/Dead staining of BMSCs within the oriented (E, F) and the random (I, J) scaffolds on day 7; Examination of distribution of cell nuclei (blue: DAPI-stained) (G, K) in oriented (H) and random scaffold (L).Scale bar: 200 μm.
Fig 4.
Cell proliferation assay within scaffolds.
Proliferation of differentiated BMSCs seeded on the oriented scaffold (filled squares) or the random scaffold (circles). *, p < 0.05.
Fig 5.
Experimental design and cartilage repair at 6 weeks post-implantation.
Cell-scaffold constructs were implanted into the cartilage defect: oriented scaffold group (A), random scaffold group (B), and negative control group (C). The native articular cartilage (D) was utilized as normal control. Gross appearance of the knee joint (E, F, G) and micro-CT scanning (E1, E2, F1, F2, G1, G2) of the defect at 6 weeks. HE (E3, F3, G3), toluidine blue (E4, F4, G4), safranin O (E5, F5, G5) and collagen type II staining (E6, F6, G6) of the regenerated cartilage. Scale bar: 1 mm.
Fig 6.
Articular cartilage repair at 12 weeks and evaluation of regenerated cartilage through histomorphological and biomechanical grading.
Gross appearance of the knee joint (A, B, C) and micro-CT scanning (A1, A2, B1, B2, C1, C2) of the defect at 12 weeks. HE (A3, B3, C3), toluidine blue (A4, B4, C4), safranin O (A5, B5, C5) and collagen type II staining (A6, B6, C6) of the regenerated cartilage (scale bar: 1 mm). Histomorphological (O’Driscoll) scores (D) and Young's modulus values (E) of the regenerated cartilage in the two scaffold-implanted groups, throughout the experimental period. *, p < 0.05.
Fig 7.
Articular cartilage repair at 24 weeks and biochemical evaluation of regenerated cartilage.
Gross appearance of the knee joint (A, B, C) and micro-CT scanning (A1, A2, B1, B2, C1, C2) of the defect at 24weeks. HE (A3, B3, C3), toluidine blue (A4, B4, C4), safranin O (A5, B5, C5) and collagen type II staining (A6, B6, C6) of the regenerated cartilage (scale bar: 1 mm). Biochemical evaluation showing total DNA (D), total GAG (E) and total collagen (F) in the regenerated cartilage in the two experimental groups. *, p < 0.05.