OBJECTIVETo study the therapeutic effect of chitosan-coated basic fibroblast growth factor (bFGF) slow-releasing microspheres on the knee osteoarthritis in the rabbit.

METHODSFrom November 2008 to July 2009, 54 New Zealand rabbits were divided into 6 groups at random, which were the control group, the model group, the PBS-M group, the bFGF-S group, the 10-bFGF-M group and the 100-bFGF-M group, respectively. The model of knee osteoarthritis was induced by the injection of papain in the rabbit. Except the control and model groups, all the experimental groups were implanted 1 ml intervention solution at the third and sixth weeks, including the PBS microspheres, bFGF solution, 10 µg bFGF microspheres and 100 µg bFGF microspheres, respectively. The rabbits were sacrificed at the ninth week after operation, and then articular cartilage was conducted the morphological and histopathological evaluation.

RESULTSThe damage of articular cartilage in the model group was more serious than that in the control group, with statistical differences according to the Ink score (t = 8.22, P = 0.00) and Mankin score (t = 17.20, P = 0.00). The damage of articular cartilage in the PBS-M and bFGF-S groups were similar with that in the model group, according to the Ink score (t = 0.26, P = 0.79; t = 0.80, P = 0.45) and Mankin score (t = 1.51, P = 0.17; t = 0.56, P = 0.60). The Ink and Mankin scores in the 10-bFGF-M and 100-bFGF-M groups were better than that in the model group (Ink score: t = 3.58, P = 0.01; t = 6.82, P = 0.00; Mankin score: t = 3.41, P = 0.01; t = 5.00, P = 0.00), with the 100-bFGF-M group much better (t = 5.29, P = 0.00; t = 2.80, P = 0.02).

CONCLUSIONSThe bFGF slow-releasing microsphere can keep its effective intra-articular concentration, which may accelerate the synthesis of proteoglycan and inhibit its decomposition to reverse the damage of articular cartilage.