PRP treatment effects on degenerative tendinopathy - An in vitromodel study

Abstract

Platelet-rich plasma (PRP) has become a popular option for the treatment of injured tendons. However, the efficacy of PRP treatment is a matter of heated debate in orthopaedics and sports medicine. In this study, we used a cell culture model to evaluate the potential effects of PRP treatment on degenerative tendinopathy. The in vitro model, which uses the current concept of "diseases-in-a-dish", consisted of tendon stem/progenitor cells (TSCs) that were derived from rabbit tendons and cultured in differentiating media with and without autologous platelet-rich clot releasate (PRCR). We found that 10% PRCR treatment of TSCs blocked their non-tenogenic differentiation, as evidenced by the marked decrease in lipid droplets, proteo-glycan accumulation, and calcium deposition on cell surfaces. Moreover, the protein markers for non-tenocytes (adiponectin, collagen type II, and osteocalcin) were either minimally expressed or greatly reduced. However, after TSCs underwent non-tenogev nic differentiation by pre-treatment in non-tenogenic media for two days, PRCR only slightly reduced adipogenesis and osteogenesis of TSCs, although chondrogenesis was markedly suppressed. Finally, PRCR treatment after pre-treatment of TSCs in non-tenogenic media for one week had little effect on any of the three non-tenogenic differentiations of TSCs. These findings suggest that the injection of PRP in clinics may not be able to effectively reverse the degenerative conditions of late-stage tendinopathy, which are characterized by lipid depositions, pro-teoglycan accumulation, and calcification, either alone or in combination.