Résumé
BACKGROUND: The development of cartilage tissue engineering provides novel ideas for treatment of articular cartilage defects and implements construction of tissue-engineered cartilage in vivo.OBJECTIVE: To investigate the feasibility of constructing tissue-engineered osteochondral composite through bone marrow stem cells(BMSCs) cultured on the poly(lactide-co-glycolic acid) (PLGA), which was modified with collagen and cellular growth factors.METHODS: PLGA was made by phase separation technique, composited with collagen Ⅱ, basic fibroblast growth factor, and transforming growth factor-β1. The BMSCs of passage 3 were cultured on the above scaffolds. Thirty-six SD rats were randomly divided into experimental, control, and blank groups. These three groups received implantation of BMSCs composited with growth factors and collagen-PLGA, implantation of BMSCs composited with collagen-PLGA, and implantation of collagen-PLGA into the muscle, respectively. At 4, 8, and 12 weeks after surgery, cell directional differentiation and growth were examined by gross observation, hematoxylin-eosin staining, toluidine blue staining, collagen Ⅱ staining, and scanning electron microscope.RESULTS AND CONCLUSION: Gross observation showed that there were many chondroid tissues in the experimental group and fibrous tissues in the control and black groups. Stainings and electron microscope revealed that many chondroblasts and a few osteoclasts appeared in the composite of the experimental group. Toluidine blue and collagen Ⅱ stainings were positive in the experimental group and negative in the control and blank groups. These findings demonstrate that PLGA modified with collagen had a good cellular compatibility. BMSCs cultured on PLGA, which was modified with collagen and cellular growth factors, can construct the tissue-angineered osteochondral composite in rats.
Résumé
It is currently reported that extracellular matrix, biological scaffolds, conditions of stress, nutrients and metabolic waste play very important roles in tissue-engineered osteochondral composite. In this paper, we have made a review of their effects on such composite.