Fig. 2

Characterization of DDFS and fish GelMA hydrogel. a (i) General observation of the fish scale before and after decellularization and decalcification (scale bar: 1 mm). (ii-iii) H&E and Masson trichrome staining of fish scales before and after decellularization and decalcification (scale bar: 100 μm). b The stress-strain curves of fish scales before and after decalcification. c The quantitative analysis of Young’s modulus (n = 3, mean ± SD). d SEM images of fish scales after decellularization and decalcification (scale bar: 100 μm). e EDS measurements of fish scales after decellularization and decalcification. f General observation and SEM image of hydrogels derived from fish GelMA (scale bar: 100 μm). g The mass swelling ratios of fish scales and hydrogels with different concentration of fish GelMA (n = 4, mean ± SD). h The self-curling process of DDFS and fish GelMA hydrogel hybrid scaffold (scale bar: 1 mm). i Cross-sectional SEM image of SCOS (scale bar: 50 μm). j FTIR analysis of fish GelMA hydrogel, DDFS and SCOS. ** p < 0.01, by two-tailed Student’s t test