Fig. 3

a Cytotoxicity assay of USCs cultured with the extraction medium using CCK-8 test. The cross-linked scaffolds containing 0%, 0.01%, 0.05%, 0.1%. 0.5%, and 1% GO were labeled “0%,” “0.01%,” “0.05%,” “0.1%,” “0.5%,” and “1%.” b and c Hemolysis test of each scaffold. d Live–dead staining images of USCs cultured on scaffold for 7 days (green representing living cells and red representing dead cells, scale bar = 100 μm). Statistically significant differences are indicated with *p < 0.05 and **p < 0.01 versus the 0% group