Age-Related Changes of Chondrogenic Growth Factors in Platelet-Rich Plasma

Abstract

Platelet-rich plasma (PRP) injections are a novel biological modality to promote tendon and ligament healing. PRP contains many growth factors that play critical roles in chondrogenesis , including insulin-like growth factor 1 (IGF-1), human growth hormone , transforming growth factor beta 1 , basic fibroblast growth factor , and bone morphogenetic proteins 2 , 4, and 7. Because articular cartilage degeneration is correlated with age, it is important to understand whether PRP contains sufficient levels of autologous growth factors across different age-groups for clinical applications in chondral regeneration or repair. PRP was isolated from 40 healthy volunteers between 20 and 60 years of age, and concentrations of bone morphogenetic proteins 2 and 4, basic fibroblast growth factor, human growth hormone, IGF-1, insulin-like growth factor-binding proteins 2 and 3, platelet-derived growth factor BB (PDGF-BB), transforming growth factor beta 1, and vascular endothelial growth factor were analyzed by enzyme-linked immunosorbent assay. Significant differences with respect to age were detected between subjects less than 30 and >30 years of age for PDGF-BB ( P < 0.001), insulin-like growth factor-binding protein 3 ( P < 0.001), and IGF-1 ( P = 0.015). A significant difference was also detected between subjects <40 and >40 years of age for PDGF-BB ( P = 0.015). Concentrations of other growth factors did not vary significantly across age-groups, suggesting that the molecular contents of therapeutic potential of PRP are similar for patients aged 20-60 years. Additional research is warranted to establish whether PRP may be beneficial for chondrogenesis in clinical practice and to determine the optimal mix of growth factors for orthopedic applications.