This paper presents a new method of delivering shRNA with biodegradable, thermosensitive PLGA-PEG-PLGA hydrogels for gene treatment of osteoarthritis （OA）. OA is a chronic debilitating disease. Without the proper treatment and prognosis, it may result in the loss of joint function in aged people. Currently, gene therapy targeted on WISP-1 has emerged as an alternative method for OA treatment. In order to constantly release shRNA at 37.0 ℃, we synthetized the hydrogels via ring-opening copolymerization of lactide （LA） and glycolide （GA） using Polyethylene glycol （PEG Mn = 1000） and stannous octoate （Sn（Oct）2, 95%） as the macroinitiator and catalyst. First, the PLGA-PEG-PLGA copolymer was mixed with WISP- 1 shRNA and PEI-Lys in distilled water at 4.0 ℃. Then, the WISP-lshRNA/PEI-Lys loaded hydrogel was formed after incubation of the mixed solution at 37.0 ℃. During tests, the plasmid was released from this hydrogel complex constantly, and enhanced the transfection efficiency of WISP-1 shRNA. In addition, silencing WISP-1 results to lower expression of MMP-3 and ADAMTS, and the accumulation of HBP 1 in synoviocytes. Therefore, the hydrogel containing WISP-1 shRNA is demonstrated an efficient way for the treatment of OA.
