[Conduction of injectable cartilage using fibrin sealant and human bone marrow mesenchymal stem cells in vivo].

OBJECTIVE To investigate the feasibility of the complex of the fibrin sealant (FS) and the bone marrow mesenchymal stem cells(MSCs) to create a new cartilage in the nude mice by the issue engineering technique. METHODS The MSCs were isolated from healthy humans and were expanded in vitro. And then the MSCs were induced by the defined medium containing the transforming growth factor beta1 (TGF-beta1), dexamethasone, and ascorbic acid. The biomechanical properties of the chondrocytes were investigated at 7 and 14 days. The MSCs induced for 7 days were collected and mixed with FS. Then, the FS-MSCs mixture was injected by a needle into the dorsum of the nude mice in the experimental group. In the two control groups, only FS or MSCs were injected respectively. The specimens were harvested at 6 and 12 weeks,and the ability of chondrogenesis in vivo was investigated by the gross observation, HE, Alcian Blue staining, and type II collagen immunohistochemistry. RESULTS The MSCs changed from a spindle-like fibroblastic appearance to a polygonal shape when transferred to the defined medium, and could be induced to express the chondrocyte matrix. After an injection of the mixture, the cartilage-like tissue mass was formed, and the specimens were harvested from the mass at 6 and 12 weeks in the experimental group. The tissue mass at 6 weeks was smaller and relatively firm in texture, which had a distinct lacuna structure. And glycosaminoglycan (GAG) and Type II Collagen expressions were detected. The tissue mass at 12 weeks was bigger, firmer and glosser with the mature chondrocytes lying in the lacuna structure. The positive Alcian blue and Collagen II immunohistochemistry stainings were stronger at 12 weeks than at 6 weeks. But there was no cartilage-like tissue mass formed in the two control groups. CONCLUSION This study demonstrates that the fibrin sealant and the bone marrow mesenchymal stem cells can be successfully used in a constructing technique for the tissue engineered injectable cartilage.