Macrophages-mediated delivery of protoporphyrin for sonodynamic therapy of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease characterized by infiltration of inflammatory cells, hyperplasia of synovium, and destruction of the joint cartilage. Owing to the low drug delivery efficiency and limited immunosuppression effect, complete cure for RA remains a formidable challenge. Here, we show that live macrophages (Mφs) carrying protoporphyrin-loaded FeO nanoparticles can migrate to the RA tissues and inhibit the inflammation by sonodynamic therapy. The inflammation of RA leads to the release of cytokines, which guides the migration of the Mφs into the RA tissues, realizing precise delivery of therapeutics. The following sonodynamic therapy induced by ultrasound and protoporphyrin destructs the proliferating synovial cells and also infiltrated inflammatory cells, demonstrating significant therapeutic effect for RA. Meanwhile, the cytokines and relapse of RA can be remarkably suppressed because of the efficient damage to the resident inflammatory cells.