Objective To investigate the effect of recombinant adenovirus-mediated basic fibroblast growth factor (bFGF),interleukin-1 receptor antagonist protein (IL-Ra) and insulin-like growth factor(IGF)-1 gene transfection on human osteoarthritis chondrocytes.Methods Monolayer cultures of human osteoarthritis chondrocytes were transfected with recombinant adenovirus carrying genes encoding the following cytokines: human bFGF,IL-1Ra and IGF-1.Six days later,levels of gene expression and glycosaminoglycan (GAG) in culture supernatant were detected.The proliferation and apoptosis of chondrocytes were analyzed by methyl thiazolyl tetrazolium (MTT) and flow cytometry respectively.Matrix biosynthesis was observed by toluidine blue staining and immunohistochemistry examination of type Ⅱ collagen.The expression of type Ⅱ collagen,MMP-3 and TIMP-1 were analyzed by immunoblotting.Comparisons between groups were performed with one-way ANOVA analysis.Results The expression of all transgenes was high following adenoviral transfection compared with the OA control group (P<0.05).The delivery of bFGF alone promoted the cell proliferation and resulted in a significant enhanced biosynthesis of type Ⅱ collagen and proteoglycans of chondrocytes (P<0.05).Compared with bFGF transfection alone,as two or three of the genes were transfected in different combinations,apoptosis rate of chondrocytes was decreased [(26.1±1.6)%,(19.4±1.0)%.(18.4±1.1)%,(13.9±1.8)%.respectively P<0.05].There was marked enhancement of matrix synthesis and expression of TIMP-1.At the same time,the expression of MMP-3 was inhibited.Conciuslon The bFGF gene transfection mediated with adenoviral vectors can greatly promote cell proliferation and increase matrix synthesis in vitro. Compared to the expression of bFGF alone, concomitant gene transfection of bFGF, IL-IRa and IGF-1 in different combinations plays a complementary role, further enhances matrix synthesis and inhibits matrix degradation.