Figure 3.

The effect of aromatic thiols on allyl sulfide hydrogel degradation kinetics. a. When equilibrated with the aromatic thiol, 4MPAA, AS-PhAA (blue) hydrogels degrade rapidly, while AS-PA (red) and AS-AA (green) hydrogels experience limited degradation. b Apparent rate constants for photodegradation of crosslinkers AS-PA, AS-AA, and AS-PhAA using 4MPAA are shown. Significance determined by one way ANOVA, N=3, mean ± s.d., **p < 0.01. c AS-PhAA crosslinked hydrogels equilibrated with 4MPAA degrade more rapidly at pH 5 (dash) than at pH 7.4 (solid). d Apparent rate constants for photodegradation of AS-PhAA using 4MPAA at pH 5 and pH 7.4 are shown. Significance determined by t test, N=3, mean ± s.d., **p < 0.01. Hydrogels equilibrated with 15 mM soluble thiol and 1 mM LAP at pH 7.4 (or pH 5) were exposed to light (365 nm, 5 mW cm⁻²) at t = 0. All rheological plots show a representative trace from N=3.