Growth Factors and Articular Cartilage Rejuvenation: Where are we up to with reversing OA?

Osteoarthritis has eluded a curative/disease modifying treatment despite extensive research over the last century. This is largely due to the extremely slow metabolic turnover of articular cartilage in an essentially avascular environment, along with a pro-catabolic inflammatory cascade that is induced by damage to the healthy cartilage structure. There has been promising data emerging whereby this poor chondrocyte healing process can be improved by applying autologous stem cell populations (harvested from marrow/adipose tissue) that have been programmed to undergo rapid and sustained chondrogenesis with the assistance of numerous chondrogenic growth factors. Here we aim to provide a comprehensive review article about the growth factors employed for the purpose of articular cartilage rejuvenation. Disease modifying agents incorporating chondrogenic growth factors have been extensively researched in the last 2 decades, and it has been identified that the likely chondrogenic growth factor families of most therapeutic value are the Transforming Growth Factor beta (TGF-B superfamily), Fibroblastic Growth Factor (FGF - specifically FGF-18) and Insulin Growth Factor (IGF) in combination with many of the aforementioned factors. There is still a need for consensus on appropriate dosing and long-term studies should be performed to assess the durability of current therapies over many years. The application of growth factor enriched stem cell populations to osteoarthritic cartilage appears to be very near to effective therapeutic use.