Fig. 2
Characteristics of type I collagen scaffolds and phenotypic analysis of OA chondrocytes during 3D culture in collagen I scaffolds. a General view of collagen I scaffolds in vitro. b Live cell staining of chondrocytes in type I collagen scaffolds. Scale bar = 1 mm. c Dead cell staining of chondrocytes in type I collagen scaffolds. Scale bar = 1 mm. d Gross morphology of type I collagen scaffold constructs after implantation. e P1, P3, and P5 OA chondrocytes were seeded into type I collagen scaffolds for 3D culture at a seeding density of 2 × 106 cells/ml. After 2 weeks of in vitro culture, gene expression profiles of different sets of OA chondrocytes in type I collagen scaffolds and monolayer culture were assessed (n = 3 in each group). *p < 0.05, **p < 0.01, and ***p < 0.001; data are mean ± standard