Figure 1.

Thiol–maleimide hydrogel synthesis and photodegradation. a) Poly(ethylene glycol)‐based multifunctional thiol and maleimide macromers were used to synthesize crosslinked networks in PBS containing 5 wt.% macromer and LAP as a photoinitiator (0.5 wt.% unless noted). b) Network formation occurs via thiol–Michael reaction between thiol and maleimide end‐groups, forming a thiosuccinimide adduct. c) Crosslinked networks are irreversibly degraded by photoinitiated radical generation. d) Network formation and degradation were monitored by in situ oscillatory shear rheology (1% strain, 1 rad/s) for hydrogels with varied LAP concentration and f) varied thiol:maleimide molar ratios. Michael addition was allowed to proceed for 20 min, followed by 10 min of 365 nm light exposure (5 mW cm⁻²) and 5 min in the dark. Storage moduli of the hydrogel after Michael addition (dark bars) and after UV exposure (light bars) are compared for e) varied LAP concentration and g) varied thiol:maleimide molar ratios.