Effects of kartogenin/PLGA nanoparticles on silk scaffold properties and stem cell fate

Cartilage is an avascular and aneural connective tissue with poor self-healing capability. Recently, tissue engineering opens up new horizons for staving off or treating cartilage lesions. In this work, kartogenin (KGN), a small chondro-inductive molecule, was loaded into poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), which in turn was embedded in a silk fibroin (SF) scaffold, to prepare an appropriate microenvironment for mesenchymal stem cell (MSC) differentiation. In this research, SF was opted to serve as a scaffold based on its approved biocompatibility and non-toxicity, excellent mechanical properties and processability. The data obtained from this study show that entrapment of KGN in NPs provides sustained release, which could promote the differentiation of MSCs into chondrocytes. Likewise, the scaffold containing KGN-loaded NPs induces glycosaminoglycan production by the seeded MSCs. The introduction of NPs into the scaffold, meanwhile, elevated the compressive strength of the structures (more than two times) without any significant effect on their swelling behavior. Taken together, the authors’ findings demonstrate that the prepared scaffold, with an optimal structure, could be a potential candidate for cartilage tissue regeneration.