Figure 7.

Schematic depiction of colitis treatment by INF@PPNP. With oral treatment into mice, the INF@PPNP aggregate into large size nanoparticles (>300 nm) at acid pH value in the stomach. The aggregated nanoparticles can protect the INF from degradation by pepsin. After the aggregated nanoparticles transferred into the small intestine, it can be reversed into small size nanoparticles (~100 nm) at neutral pH value. And the nanoparticles can be captured by positively charged proteins of inflamed colon surface and penetrated into colon tissue with high epithelial permeability. The INF can be released by degradation of the nanoparticles by high ROS level in the inflammation tissue.