论文部分内容阅读
目的 :研究利用3D打印的支架材料制作组织工程骨并植入大鼠牙槽突裂区,邻牙受正畸力向植骨区移动对植入骨改建的生物学影响。方法:选取12只8周龄SD大鼠,制备双侧上颌牙槽突裂标准动物模型。利用3D打印的组织工程支架材料与大鼠骨髓间充质干细胞(BMSCs)体外共培养后,作为植入材料,植入动物体内。术后8周处死3只大鼠取材,H-E染色评价成骨,并行单侧植骨区邻牙加力移入,非加力侧为对照组。在加力1、3、7 d后分别处死3只大鼠取材,采用实时荧光定量PCR技术(RT-PCR)检测成骨相关基因Runx2、OCN和VEGF的表达,应用SPSS19.0软件包对实验组和对照组的基因表达样本均数进行t检验。结果:H-E染色显示,手术区骨组织成熟,成骨良好。RT-PCR显示,Runx2呈现早期到中期增高,而到晚期再降低的趋势;OCN的表达在早期到中期无显著变化,到晚期升高明显;VEGF表达在加力早期到中期再到晚期呈现逐渐降低的趋势;而早、中、晚期实验组的各项成骨相关基因表达均显著高于对照组(P<0.05)。结论:3D打印支架材料构建的组织工程骨可以很好地替代自体骨移植,以达到良好的成骨效果。正畸手段使邻牙移入植骨区,可以有效促进术区成骨,并且诱导成骨细胞及破骨细胞进行骨改建。
OBJECTIVE: To study the biological effect of using 3D printed scaffolds to make tissue engineering bone and implanted into the rat alveolar cleft zone. Methods: Twelve SD rats of 8 weeks old were selected to prepare a standard animal model of bilateral maxillary alveolar cleft. The tissue-engineered scaffold material using 3D printing was co-cultured with rat bone marrow mesenchymal stem cells (BMSCs) in vitro and then implanted into animals as an implant material. Three rats were sacrificed at 8 weeks after operation. H-E staining was used to evaluate the osteogenesis. The adjacent one-sided bone graft was implanted with adjacent teeth and the non-afterburned side served as the control group. Three rats were sacrificed on day 1, day 3 and day 7, respectively. The expressions of Runx2, OCN and VEGF were detected by real-time fluorescence quantitative PCR (RT-PCR) The mean of gene expression samples of the group and the control group was t-test. Results: H-E staining showed that the bone tissue in the operation area was mature and well-formed. RT-PCR showed Runx2 increased from early to mid-stage, then decreased to the late stage. The expression of OCN had no significant change from early to mid-stage and increased significantly in late stage. The expression of VEGF increased gradually from early to middle to later stage (P <0.05). However, the expressions of osteogenesis-related genes in early, middle and late experimental groups were significantly higher than those in control group (P <0.05). Conclusion: The tissue engineered bone constructed by 3D printing scaffolds can be a good alternative to autologous bone grafts to achieve good osteogenesis. Orthodontic means to move the adjacent teeth into the bone graft area, can effectively promote the operation of bone formation, and induction of osteoblasts and osteoclasts for bone remodeling.