Fig. 6

Gradient Heterogeneous Osteochondral Regeneration by Organoid/GelMA Cylinder Guided by a Gradient Vascular Microenvironment in a Rabbit OCD Model. a Schematic representation of gradient heterogeneous osteochondral regeneration in a rabbit OCD model via in situ implantation of organoid/GelMA cylinder. b Gross observation, 3D reconstruction, and 2D imaging of repaired joint tissue at 12 weeks post-treatment in the empty, GelMA, and organoid/GelMA groups. Red dotted circles and squares indicate the OCD regions. c Quantitative analysis of ICRS macroscopic scores, Tb.Th, and BV/TV for the regenerated joint tissue in the empty, GelMA, and organoid/GelMA groups. n = 5; **p < 0.01, ***p < 0.001, ****p < 0.0001. Representative d H&E and e Saf-O/FG staining of regenerated joint tissue at 12 weeks. OCD areas are highlighted by two black arrows. Enlarged views of the cartilaginous zone (green squares), transition zone (red squares), and subchondral osseous zone (yellow squares) are shown. Cartilage matrix is denoted by #, and bone matrix is denoted by *