Figure 1.

Schematic illustration of orally targeted delivery of L-Arginine based pH-activated “nano-bomb” carrier in hydrogel for site-specific treatment of ulcerative colitis. (A) PS-L-Arg-CO₂@NPs (NPs) with pH-activated “nano-bomb effect” were fabricated by double-emulsion technique. Then, the nanoparticles were linked with hyaluronic acid (HA) to endow their active targeting ability (HA-PS-L-Arg-CO₂@NPs, HA-PS@NPs). (B) HA-PS@NPs were loaded in chitosan/alginate hydrogel for site-specific treatment of ulcerative colitis by regulating gene silencing and the level of reactive oxygen species (ROS) via oral administration.