Many inflammatory diseases are associated with reactive oxygen species(ROS) in the body. The bilirubin nanoparticle has strong antioxidant, ROS scavenging, and immune modulating properties which effectively eliminate the disease-causing ROS.
Bilirubin nanoparticles have higher therapeutic effects as it can scavenge ROS at the actual site of inflammation due to Enhanced Permeability and Retention (EPR) effect.
Once the bilirubin nanoparticles react with ROS, it breaks down into PEGylated biliverdin which is completely water soluble as an individual molecule and excreted out of the body easily.
The therapeutic effects of bilirubin nanoparticle has been shown in 9 different acute and chronic disease animal models such as myocardial infarction ischemic reperfusion injury, inflammatory bowel disease, asthma, ischemic reperfusion injury in organ transplantation, GvHD, psoriasis, multiple sclerosis, and other inflammatory related diseases.
The colitis model mice (inflammation induced by providing water containing 3% DSS) showing little evidence of bleeding, colon shortening, or abnormal stools when treated with bilirubin nanoparticles via intravenous injection indicating anti-inflammatory effects.
The first image shows that there is no localization of bilirubin nanoparticle when inflammation is not induced. The below biodistribution image shows that when injected with indocyanine green loaded bilirubin nanoparticles in inflammation-induced mice (provided with water containing 3% DSS), localization of bilirubin nanoparticles in inflamed colon can be seen.
[Reference: Angew. Chem. Int. Ed. 2016, 55, 7460-7463]