Sulforaphane-PLGA microspheres for the intra-articular treatment of osteoarthritis

Sulforaphane (SFN) is a member of the isothiocyanate family that has anti-inflammatory action as well as anti-carcinogenic properties. The authors have devised an intra-articular injectable SFN-PLGA microsphere system that can be used for treating osteoarthritis (OA). The purpose of this study was to evaluate the in vitro and in vivo efficacy of the SFN-PLGA microsphere system. Articular chondrocytes were obtained from knee OA patients and were cultured in monolayers. The optimal concentration of SFN was obtained and the dose of SFN-PLGA microspheres was determined based on the concentration. The in vitro anti-inflammatory effect on markers such as cyclooxygenase (COX)-2, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-5, and matrix metalloproteinase (MMP)-2 was assessed by real-time PCR and Western blotting. The in vivo therapeutic effect of SFN-PLGA microspheres was investigated using surgically-induced rat OA model. Treatment with SFN-PLGA microspheres inhibited the mRNA and protein expression of COX-2, ADAMTS-5 and MMP-2 induced by LPS in articular chondrocytes. Intraarticular SFN-PLGA microspheres delayed the progression of surgically-induced osteoarthritis in rats. In conclusion, SFN-PLGA microspheres can be a useful injectable delivery system for treating osteoarthritis.