Figure 3.

(A) DLS size distribution of oxNG2-DFO dispersed in ddH₂O (black line), 1% H₂O₂ (blue line), and 5% H₂O₂ (red line) after 240 h incubation at RT. (B) Changes in the apparent molecular weight of oxNG2-DFO in the presence of 1% and 5% H₂O₂ as monitored by GPC at RT (C) Images of oxidation responsive bulk hydrogel slabs incubated under various oxidative stress conditions: (top row) H₂O₂ 0%; (middle row) H₂O₂ at 5%; (bottom row) H₂O₂ at 5%/FeCl₃ (0.1mg/mL). Hydrogel slab was stable in H₂O with no significant shape change observed up to 960 h incubation; hydrogel in 5% H₂O₂ could no longer be observed with the naked eye after 60 h incubation; in the presence of 5% H₂O₂ and FeCl₃, hydrogel slab visually degraded completely after 12 h incubation. This is likely due to the known catalytic role Fe(III) plays in oxidizing H₂O₂ to generate ROS and thus elevating oxidative stress levels even further.