The Construction Of Tissue Engineering Tubiform Bone Graft With Cell Sheet Technique

Tissue reconstruction and reparation remains one of the most challenging tasks in the clinical surgery. Tissue engineering provides a novel approach to solve this problem. Bone tissue engineering is one of the focal points in tissue engineering, which involves seed cells, scaffolds and growth factors.Objective: To regenerate tissue engineered bone graft with favorable contour, adequate volume and enough strength for clinical application. In details: 1.To explore how to get more seed cells in cell culture and high efficiency in cell usage in tissue fabrication. 2. To regenerate three-dimensional bone graft in vitro with cell sheet and without the traditionally used scaffolds. 3. To establish strtegy of regenerating tissue engineered bone by bioreactor in vitro. 4. To observe the differentiation ability and stability of the tissue engineered bone graft in vivo.Methods and results: Rabbit bone marrow stromal cells (BMSCs) were cultured continuously to form a cell sheet with proper mechanical strength and convenient handling property. The characteristics of the cell sheet were studied. Tubiform bone graft was fabricated by rolling the cell sheets around a glass tube and cultured in bioreactor in vitro. The results showed that the sample had certain mechanical strength. Further more, we implanted the tubiform bone graft subcutaneously into nude mouse for 1-2 months and finally we got a tissue engineered bone graft which resembled to the natural bone both in the appearance and the structure. At the same time, we found out the construction and maturity of the tissue engineering bone can be influenced by adding coral granules into the cell sheet.Conclusions: These results provide direct evidence that the special contour-bionic tissue engineered bone can be reconstructed with the strategy of cell sheet with coral granules plus external supporting scaffold in bioreactor. The bone graft became maturation and similar to natural bone after implanted into the animal body. Cell sheet strategy together with silicone tube as external support provides a novel approach to construct tubiform bone graft. We believe that this novel strategy has great potential in futue clinical application...