Figure 5. Effect of gelatin concentrations on GelMA synthesis.

Error bars indicate the relative standard deviations of three independent measurements (n = 3). (A) pH transition kinetics during the reaction. (B) DS versus gelatin concentration. DS was obtained from TNBS assay. Gelatin solutions at 10 w/v% and above led to a high DS. (C) ¹H NMR verification. Peaks correspond to acrylic protons (2H) of methacrylamide grafts of lysine groups (a) and those of hydroxyl lysine groups (b), methylene protons (2H) of unreacted lysine groups (c), and methyl protons (3H) of methacrylamide grafts (d).