Effect of Platelet-Rich Plasma on Chondrogenic Differentiation of Adipose- and Bone Marrow-Derived Mesenchymal Stem Cells

Post-traumatic and focal cartilage defects of the knee affect over 3 million Americans annually. Autologous cell-based cartilage repair, for example, autologous chondrocyte implantation, is limited by the need for ex vivo chondrocyte expansion and donor site morbidity. Mesenchymal stem cells (MSCs), owing to their relative ease of isolation, higher replication activity, and chondrogenic potential, represent an alternative reparative cell type. Platelet-rich plasma (PRP) is an autologous, growth factor-rich biologic preparation that has recently received increasing attention and use as a therapeutic adjunct for the treatment of degenerative joint diseases, and there is evidence suggesting that PRP acts by promoting stem cell proliferation and tissue healing. In this study, we have examined the effect of PRP treatment on chondrogenic differentiation of adult human MSCs derived from infrapatellar fat pad-adipose stem cells (IFP-ASCs) and bone marrow (BM-MSCs). Both cell types were placed in high-density pellet culture and hydrogel-encapsulated culture under chondrogenic conditions. Our results showed that PRP did not improve IFP-ASC or BM-MSC chondrogenesis. In general, chondrogenesis was inhibited with increasing PRP concentrations and duration of exposure, on the basis of histological, biochemical, and gene expression analyses. Taken together, these findings suggest that although PRP is reported to be beneficial in terms of pain relief and joint function improvement, its mechanism of action is unlikely to directly involve enhancement of MSC-mediated hyaline cartilage formation.