Application of kartogenin for musculoskeletal regeneration.

Kartogenin (KGN) is a recently characterized small molecule that promotes the selective differentiation of mesenchymal stem cells into chondrocytes, and thus, KGN stimulates cartilage regeneration. KGN also possess chondro-protective effect. Furthermore, because it is a highly stable small molecule, KGN can be stored and transported at room temperature. These obvious superiorities over peptide growth factors make KGN a desirable chondrogenic agent for cartilage regeneration. Since its discovery, KGN has drawn much attention as a new chondrogenic drug for intraarticular (IA) treatment. Although it was originally developed with a focus on OA, it has been used to treat other conditions and to promote disc and bone-tendon junction regeneration. Our group has also developed several formulations for IA delivery of KGN including KGN-conjugated chitosan nano/microparticles, thermo-responsive polymeric nanospheres based on chitosan oligosaccharide conjugated pluronic F127, and hyluronate hydrogels containing polyethylene glycol (PEG/KGN) micelles. This review was undertaken to summarize current research on the action mechanism of KGN and the various formulations described in the literature that induce musculoskeletal regeneration.