Masson’s trichrome stained MDP hydrogel implants unloaded and loaded with CDN, injected subcutaneously in the dorsal flank of mice. Time point shown is 3 days post injection, at which time hydrogel implant was removed and processed for histology. Scale bars in panels A and D = 1 mm; scale bars in panels B, C, E, and F = 0.1 mm. (A-C) MDP unloaded control implant at 4× magnification showing even infiltration of cells, with boxes drawn around chosen areas whose 40X counterparts are shown in panels B and C, respectively. (D-F) MDP implant loaded with 910 μM CDN (STINGel) at 4× magnification showing uneven infiltration of cells across the implant. Boxes drawn around chosen areas in panel D again have 40X counterparts shown in panels E and F, respectively.