3.3 Combination of two-step crosslinking approach
Two-step crosslinking resulted in substantial cohesion. Figure 3A showed that 10 s pre-crosslinked GelMA can be re-crosslinked with uncrosslinked GelMA bioink and formed a united combination. There was no sign of splitting at the combining site under the SEM observation (Figure 3b). In tensile loading, there was no significant difference in Young’s modulus and tensile strain between structures formed by one-step or two-step crosslinking methods (P >0.05) (Figure 3C-3D).