Fig. 8

Effect of EVs in FEC hydrogel on the disc degeneration ex vivo. A Diagrammatic sketch of the ex vivo disc degeneration model. B Ex vivo imaging on X-ray and fluorescence pattern of disc at Day 1, Day 7 and Day 14 (left panel). The mean fluorescence intensity in the EVs and EVS@FEC group was quantified (right panel). C The %DHI of disc was calculated correspondingly. D Hematoxylin and eosin (HE), Safranin O-fast green (S–O), and Masson staining of disc organ in each group. E Histological grades of disc based on histological staining. Data were presented as mean ± SD of six independent replicates. P > 0.05 (ns, not significant), *P < 0.05, **P < 0.01, and ***P < 0.001