Abstract: Objective To explore the effect of different induction time in vitro on the histological characters of the cartilaginous tissue conducted by bone marrow stromal cells(BMSCs).Methods Porcine BMSCs of the second passage were injected into polyglycolic acid / polylactic acid discs.The biomaterial scaffold is 12 mm in diameter and 3 mm in thickness.The constructs were induced by a combination of TGF-β1(10 ng/mL),IGF-I(50 ng/mL),and dexamethasone(40 ng/mL) 1 week and 4 weeks respectively and were compared with control group(BMSCs group and cartilage cells group).The relationship between the different induced time was analyzed and compared thoroughly.Results The histological structure of the groups induced 4 weeks is more solid than the group induced 1 week.Protein levels of cartilage special matrix(such as proteoglycan and Ⅱ type collagen et al) of the BMSCs-PGA/PLA construct induced 4 weeks in vitro detected with histological stain was superior to the groups induced 1 week.Conclusion The induction time is of great importance for BMSCs to develop into cartilage,and the longer of the inducing time,the stronger of the specific matrices expression.

Key words: Tissue engineering, Bone marrow stem cells, Induction