Figure 8.

Antioxidant properties of CS/OP hydrogels: (a) absorbance of DPPH solution before (control) and after mixing with unloaded (A₀, B₀, C₀) and CO-loaded CS/OP hydrogels (A, B, C, D); (b) antioxidant activity of CO-loaded CS/OP hydrogels as a function of immersion time; (c) photographs of the DPPH solution in the absence and presence of the hydrogels after 24 h of immersion, and (d) photographs of the color change of the DPPH solution over time after mixing with CO-loaded CS/OP hydrogels (A = CS/OP_0.5-C₁, B = CS/OP₁-C₁, C = CS/OP₂-C₁, D = CS/OP₁-C₅). Results are expressed as means ± standard deviation (S.D.) of three experiments (n = 3).