动物造模,药效评价,骨缺损修复 z-bio 2024-09-18 441

　　Implant restoration has been increasingly widely used in clinical practice, but tooth loss due to trauma, tumors, periodontal disease, and other reasons is often accompanied by excessive absorption of alveolar bone, resulting in insufficient bone mass and limiting the scope of application of implant dentures. Wang Rong et al. used Chinese experimental miniature pigs to combine bone marrow stromal stem cells with a composite of hydroxyapatite and tricalcium phosphate to form a biomaterial composite, which was applied in conjunction with peri implant bone defects to analyze the tissue regeneration characteristics of peri implant bone defects.

　　Experimental steps: ① Extraction and induction of differentiation culture of bone marrow stromal stem cells: Aseptically extract 5-7ml of bone marrow from the anterior superior iliac spine of miniature pigs and place it in a heparinized centrifuge tube. Using density gradient centrifugation method, cells were suspended in alpha MEM medium containing 10% fetal bovine serum, inoculated into culture bottles, and cultured in CO2 incubator. After 24 hours, the cells adhered to the wall. When the cells fused to 80%, digestion and passage were performed, and the second generation cells were taken for future use Identification of BMSCs: The seventh generation of purified BMSCs will be digested and counted. Add 100 μ l of cell suspension containing 1 × 106 cells into a centrifuge tube. Add 200 μ l PBS, centrifuge at 1000r/min for 5 minutes, resuspend cells in 200 μ l PBS, add FITC labeled CD71, CD44, CD34, CD45 monoclonal antibodies, react at room temperature in the dark for 1 hour, fix with paraformaldehyde, and detect by flow cytometry Composite culture of cells and scaffold materials: Adjust the cell concentration to 1 × 106/100 μ l, place it in a culture medium containing hydroxyapatite tricalcium phosphate carrier material, gently shake, culture under standard conditions, and set aside for use after 7 days Bone defect and repair around the implant: Prepare a cylindrical bone defect with a diameter of 3mm and a height of 5mm near the middle wall of the implant bed. Each group was implanted with BMSC-HA/TCP composite, HA-TCP material (80% tricalcium phosphate and 20% hydroxyapatite), covered with Cellfoam membrane, and tightly sutured. Eight miniature pigs were randomly divided into a cell scaffold group and a scaffold group, with four pigs in each group. Two animals were euthanized in each group at 1 and 3 months after implant implantation. Take samples separately, make bone grinding pieces, perform toluidine blue staining, and observe histology.

　　Experimental results: One month after implantation in the cell scaffold group, new bone formation was observed in the near mid bone defect area, with bright blue staining by toluidine blue. Neat arranged osteoblasts and woven bone were visible, indicating active osteogenic activity. The 3-month group shows good osseointegration, mainly composed of dense bone, which is mainly composed of mature dense bone containing a large amount of Haval system. It can be seen that most of the degradation of the stent material has been replaced by new bone, and blood vessels have grown into the gaps between the materials, without obvious inflammatory reactions. There is formation of trabecular bone and Haval system structure. One month after the implantation of the stent group, there was a significant gap between the stent material and the implant in the bone defect area. Three months later, the stent material gradually degraded and no new bone formation was observed.