Abstract:

BACKGROUND: Survival of tissue engineered bone after implantation is a major issue of bone tissue engineering, and there lacks of tissue engineered bone with strong feasibility that can be used without in vitro long-term construction and pre-vascularization.
OBJECTIVE: To evaluate the feasibility and osteogenic ability of constructing tissue-engineering bone with human umbilical cord mesenchymal stem cells as seed cells, β-phosphoric acid calcium biological ceramic as three scaffold materials, recombinant human bone morphogenetic protein-2 as a cell active factor, collagen Ⅰ as a cell activity factor slow-release material and encysted with vascular pedicle fascial flap.
METHODS: Twenty-four Wistar rats at 6 to 8 months old were selected. β-phosphoric acid calcium, human umbilical cord mesenchymal stem cells, recombinant human bone morphogenetic protein-2 and collagen Ⅰ covered with vascular pedicle fascial flap of L1-6 for the experimental group, beta phosphoric acid calcium and human umbilical cord mesenchymal stem cells surrounding with vascular pedicle fascial flap of L1-6 as control group.
RESULTS AND CONCLUSION: In both groups at 4 weeks after operation, immature bone tissue with low degree of calcification connected to the original layer board osteoid structure was visible in the holes of β-phosphoric acid calcium by light microscope. At 8 weeks, the bone tissues were closed to maturity bones in both groups, and osteoblasts around with a lot of pale purple bone matrix was located in the bone lacunae, the bone marrow cavity structure appeared, and collagen Ⅰ was visible in some areas. But bone tissue maturity in the experimental group was higher than that in the control group. The bone tissue Harford’s small tube in the experimental group was clearly visible to form multiple ossification centers, bone trabeculae and bone island all over them, and the mature shelf bone and rows of living osteoblasts cubic shaped orderly were also observed in the experimental group. At 8 weeks, bone trabecular was higher maturity, more typical and clear in the experimental group than those in the control group. There was no significant difference in new bone formation of area in two groups. It demonstrated that tissue-engineering bone encysted with vascular pedicle fascial flap had a good osteogenesis activity and vascularization and when combined with recombinant human bone morphogenetic protein-2 and collagen Ⅰ, the degree of osteogenesis was increased.