| Tissue engineering is a rising research field which regenerate thedamaged tissue and organs by the principle of cell biology and mechenics, while bone tissue engineering is the main branch of it. Bone marrow stromal cells have got the priority in the seed cells choosing list because of their traits in rich resources , little trauma to the human body, easy to get and easy to proliferate. Ceramic bovine bone (CBB) has the natural trabecular structure, and it is easy to be conducted to generate ossification, at the same time, CBB do not produce such problems as the difficulty in making the proper hole rate and hole diameter and inner connection of artificial materials during the production process. On the contrary, CBB have many good traits such as decomposition available, not immunogenic, rich resources, easy to product, and low cost, so, it became the idea scaffold for bone tissue engineering in recent years. We use CBB as scaffold , BMSC as seed cells in our study, We also use rhBMP-2 and TGF-P for they can promote the bone formation. We try to regenerate a new kind of tissue engineering bone in our study.Part I: experimental study on CBB/MBCs regenerate the defect of jaw First, we separated, cultivated, and induced(10nmol Dexamethasone 0.01mol/L P-Sodium Glycerophosphate, 50mg/L L-Vitamin C) SD rats MSCs out of their body and observed their biological characteristic alterations by inverted phase contrast microscope, the alkaline phosphatase level of cells, MTT chromometry, Von-Konssa staining and immunohistochemistry stainings.Results: 5 days later,some BMSc differentiated to be osteoblast like cells; 20 days later, many minerized nodus formed.Second, we observed the influences of different combinations between BMSC and scaffolds on the absorption, proliferation and differentiation ability of BMSc.By the result of Scan Telescope and immuohistochemistry staining, we proved that MSCs can absorb, spread and proliferate well on the CBB scaffold. Then, we embedded the induced MSCs into the CBB scaffold, and imput them under the skin of SD rats. We make sure the MSCs were from the rats themselves. Next, we observed the influences of grow factor rhBMP-2 and TGF-B on the ossification of MSCs by HE staining, Mallary staining, and image analysis. Results: CBB combined with induced MSCs can form woven bone, lameller bone under the SD rats skin, rhBMP-2 and TGF-P can promote such effects. Third, we use the complex of induced MSCs and CBB to regenerate the bone defect of mandibular. Still, we observed by HE staining, Mallary staining, and image analysis. Results: 2 weeks later, there were new bone formation around the CBB scaffold, the ossification connection had been achieved between the bone defect area and CBB scaffold.Conclusion: Our result proved that MSCs can be induced to be osteoblast like cells out of body and the induced MSCs combined with CBB can achieve prominent ossification, so, they have potential in bone tissue engineering applications.Part II : Orthodontic tooth movement after CBB/MSCs regenerate the bone defection in jawAfter the jew defect was repaired 2weeks , 4 weeks, and 8 weeks later, we put the orthodontic appliance between the first molar and incisors of SD rats, adding force on the appliance to move the first molar moving forward. Then, we observed the rebuilding of periodontal ligament and compared the results to the normal periodontal ligament to understand the influence of the regenerationnew bone on the orthodontic tooth movement. The study on the tooth movement speed showed that: the tooth movement in the bone repair area was greater that in the normal bone tissue and the main movement style was bodily movement. Observing the apical absorption and the the alveolar height alterations in the repair area, we found that the apical absorption and the alveolar height loss was less than that in the normal condition. Thus, we proved that the regenerated bone by bone tissue engineering can not have negative influences on tooth movement. Further study done on periodontal ligament...
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