Abstract
PURPOSE: Autologous platelet-rich plasma (PRP) injections are widely used in regenerative medicine, including the knee osteoarthritis (OA) therapy. This study reviewed methods to enhance PRP therapy for knee OA, aiming to boost articular cartilage recovery. METHODS: The search was conducted in the eLIBRARY, PubMed (MEDLINE), Ovid, ScienceDirect, and Google Scholar databases extracting publications available by the end of 2023. Studies were included if they simultaneously met the following criteria: (1) effect of using PRP in the recovery of hyaline cartilage damage after OA; (2) at least one way to modify the PRP protocol aimed to increase its efficiency; (3) data on the molecular mechanisms underlying the increase in efficiency of the modified PRP therapy in OA. RESULTS: The findings of this study highlight the significant role that the composition and modification of PRP protocols play in enhancing chondrogenesis for cartilage repair. Beyond the activation or non-activation of platelets or the inclusion or removal of leukocytes, which are factors that could somehow affect the effectiveness of PRP formulations, the elimination of growth factors such as vascular endothelial growth factor and epidermal growth factor, which negatively influence cartilage regeneration, offers a promising approach to optimize PRP therapy. While growth factors like transforming growth factor-β3, platelet-derived growth factor, and insulin-like growth factor have been shown to promote chondrogenesis, the removal of detrimental factors that could contribute to chronic inflammation or OA progression could significantly improve treatment outcomes. Practices such as combining with hyaluronic acid, pre-injection PRP activation, and multiple administrations are clinically common, while other methods like adjusting growth factors concentration are still in development. CONCLUSION: Various modifications of this technology allow to use molecular mechanisms involved in the restoration of hyaline cartilage and improve the effectiveness of PRP for the treatment of OA. However, significant challenges remain in standardizing PRP preparation and administration protocols. Variability in platelet concentration, growth factor composition, and activation methods complicate the assessment of efficacy and reproducibility.