The In Vitro Biological Effect Of TGF-β₁ On Human Articular Chondrocytes And The Significance Of Its Application In Cartilage Tissue Engineering

In cartilage tissue engineering field, acquiring an adequate number of seed chondrocyte with high viability is one of the prerequisites for efficient clinical utility in future.The ability to expand cells in vitro and maintain the chondrocyte phenotype is essential to the success of generating optimal tissue-engineered cartilage. However, chondrocytes proliferate slowly and are inclined to develop a progressive dedifferentiation with the loss of characteristic cartilage phenotype in monolayer culture. To solve the problem, one of the strategies is the use of a variety of bioactive factors, including several growth factors, such as BMPs, CDMPs, TGF-βs, IGFs and bFGF. The influence of different growth factors and their concentration on the proliferation and metabolism of isolated chondrocytes grown in monolayer culture has been studied extensively.Many investigators have used TGF-Pi with the purpose of engineering cartilage construction. However, owing to its pleiotropic biofunction and the influence of complex circumstances in vitro, the application of the growth factor is far from reasonableness.This study is to investigate the effects of TGF-Pi with different concentrations on the proliferation, type II collagen synthesis and morphology of human fetal articular condrocytes, cultured in monolayer from one to eight passage. The expression of type Ⅰ , type Ⅱ receptor of TGF-β and S-100 protein were also studied. In addition, the change style of culture media and the optimal concentration and stimulation frequencies of TGF-β1 were discussed preliminarily.In the study, CellTiter 96 AQueous One Solution Cell Proliferation Assay was used for cell proliferation study. Immunohistochemistry methods were used for the qualitative assay of the expresson of TGF-βRI, TGF-βR Ⅱ ,type Ⅱ collagen and S-100 protein.Enzymic Immunoassay was used for quantitive assay of type Ⅱ collagen synthesis.Image analysis system was used for semi-quantitive assay of TGF-βRI and RⅡ expression, and microphotography was used to record the morphologic changes of cultured...