Fig. 4
Antioxidant capacity and in vitro biocompatibility tests of hydrogels. A DPPH radical scavenging percentage of GH and CPGH. Free radical scavenging ratio of GH and CPGH against (B) ·OH and (C) O2.−. D Cell viability of L929 cells after incubating 4 h and 24 h with C60@PDA of different concentrations. E Cell viability of L929 cells after contacting with GH and CPGH hydrogels for 12 h, 24 h and 48 h. F In vitro hemolysis ratios of hydrogels; the positive group: Triton X-100; the negative group: saline solution. G The hemolytic assay of hydrogels: Photographs of supernatants after being contacted with Triton X-100, saline, GH and CPGH. H DCFH-DA assay for detecting ROS levels: DCF fluorescence staining images of L929 cells treated with hydrogel extracts after pretreatment with H2O2, scale bar: 100 μm. (n = 4, mean ± S.D.)