动物造模,药效评价,种植体周围骨缺损修复 z-bio 2024-07-08 401

　　Implant restoration has been increasingly widely used in clinical practice, but the loss of teeth due to trauma, tumors, periodontal disease and other reasons often leads to excessive absorption of alveolar bone, resulting in insufficient bone mass and limiting the applicability of implant dentures. Wang Rong et al. utilized Chinese experimental miniature pigs to combine bone marrow stromal stem cells with a complex of hydroxyapatite and tricalcium phosphate to form a biomaterial complex, which was applied in combination to analyze the tissue regeneration characteristics of bone defects around implants.

　　Experimental steps: ① Extraction and induced 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, cells were suspended in a culture medium containing 10% fetal bovine serum alpha MEM, inoculated into a culture bottle, and cultured in a CO2 incubator. After 24 hours, the cells adhered to the wall. When the cells fused to 80%, they were digested and passaged, and the second generation cells were taken for later use Identification of BMSCs: The purified BMSCs from the seventh generation will be digested and counted. Add 100 μ l of cell suspension to the centrifuge tube, containing 1 × 106 cells. Add 200 μ l PBS, centrifuge at 1000r/min for 5 minutes, resuspend cells with 200 μ l PBS, add FITC labeled CD71, CD44, CD34, and CD45 monoclonal antibodies, react at room temperature and 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 wait for use after 7 days Bone defects and repair around implants: Prepare cylindrical bone defects 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 complex, HA-TCP material (80% tricalcium phosphate and 20% hydroxyapatite), covered with Cellfoam membrane on the surface, and tightly sutured. Randomly divide 8 small pigs into a cell scaffold group and a scaffold group, with 4 animals in each group. Two animals in each group were euthanized at 1 month and 3 months after implantation. Take materials separately, make bone grinding plates, perform toluidine blue staining, and observe histology.

　　Experimental results: After one month of implantation in the cell scaffold group, new bone formation was observed in the proximal and middle bone defect area. Methylamine blue staining showed a bright blue color, with neatly arranged osteoblasts and woven bone, indicating active osteogenic activity. The 3-month group showed good bone union, mainly composed of dense bone, which was mainly composed of mature dense bone containing a large amount of Haversian system. It can be seen that most of the scaffold materials have been degraded and replaced by new bone, and blood vessels have grown into the gaps between the materials, without any significant inflammatory reactions. There is trabecular bone formation and Haval system structure. After one month of implantation in the stent group, there was a significant gap between the stent material and the implant in the bone defect area. After three months, the stent material gradually degraded and no new bone formation was observed.