RÉSUMÉ
Objective To investigate the effect of IGF-1 on the TGF-β3 induced chondrogenesis of MSCs encapsulated in alginate beads and its application in cartilage tissue engineering.Methods MSC chondrogenesis in alginate beads was induced by TGF-β3 and/or IGF-1.Collagen type Ⅱ,aggrecan and Sox-9 expression was evaluated by immunostaining,RT-PCR and Western blot,respectively.Scanning electron microscope and laser confocal microscope were used to observe the differentiated chondrocytes when cultured on the chitosan-based scaffold.Results TGF-β3 with IGF-1 induced MSCs in alginate beads to express the higher level of collagen type Ⅱ,aggrecan and Sox-9 than any other growth factor alone (P＜0.05).The correlation coefficient between Sox9 and collagen type Ⅱ or aggrecan was 0.95 and 0.91,respectively.The chitosan-based scaffold supported the cell's adhesion,migration and proliferation.Conlusion IGF-1 enhances the TGF-β3-induced MSC chondrogenesis via upregulating Sox9 expression.The chitosan-based scaffold is biocompatible with the differentiated chondrocytes.