Figure 2.

Dependence of pH on gelation time for hydrogel compositions noted in Figure 1b. Hydrogels were prepared by first dissolving the OND and thiol components separately in 0.001 M potassium phosphate buffer and then combining the two solutions in a 1:1 ratio of OND to thiol. Gelation was determined to be complete by the inversion test when the gel material was observed to be no longer flowing; the times reported were reproducible within ±10% for at least three replicate experiments.