原核表达的重组人骨形态发生蛋白7增高牙槽嵴的实验

背景:牙齿缺失后,牙槽骨内成骨与破骨的动态平衡被打破,牙槽嵴呈现出不可逆转的骨吸收,其后果是大量的牙槽骨丢失;骨形态发生蛋白在骨及牙齿的生长发育和创伤修复中发挥重要作用。目的:观察原核表达的重组人骨形态发生蛋白7对增强牙槽嵴的新骨形成、预防牙槽嵴吸收的作用。设计:对照实验。单位:济南市口腔医院正畸科,山东省医学科学院。材料:实验于2003-06/2004-12在山东省医学科学院完成,采用新西兰大白兔28只,雌雄不限,体质量平均2kg。方法:采用大白兔建立动物拔牙创模型,将大白兔分别拔除左、右下门牙,将骨形态发生蛋白7复合载体2块40μg植入右下门牙(为实验组),仅含磷酸盐缓冲液的空载体2块40μg植入左下门牙(为对照组),术后2,4,8及12周处死动物,取标本进行扫描电镜分析、钙含量及碱性磷酸酶活性测定。主要观察指标:①扫描电镜分析结果。②碱性磷酸酶活性及钙含量。结果:①电镜照片结果:实验组的骨创愈合比对照组提前4～6周。②碱性磷酸酶活性:实验组均明显高于对照组2周:(38.191±5.384),(19.821±2.084)μkat/g;4周:(160.815±9.669),(126.709±1.634)μkat/g;8周:(378.892±13.086),(225.212±1.884)μkat/g,P<0.01]。③钙含量:实验组均明显高于对照组2周:(5.592±0.110),(0.913±0.064)mg/g;4周:(8.654±0.177),(1.702±0.071)mg/g;8周:(25.326±0.287),(5.980±0.145)mg/g,P<0.01]。结论:原核表达重组人骨形态发生蛋白7具有良好的增高牙槽嵴、促进拔牙创愈合的作用。

Experimental study on recombinant human bone morphogenetic protein-7 expressed in prokaryocyte augmenting alveolar ridge

BACKGROUND: After loss of teeth, the dynamic equilibrium between osteoblast and osteoclast in alveolar bone is destroyed because of systematic and local factors, and residual ridge resorption and atrophy occur irreversibly, which result in the loss of massive alveolar bone. Bone morphogenetic protein-7 (BMP-7) exerts an important effect in the development and traumatic repair of bone and tooth.OBJECTIVE: To investigate the effect of human recombinant bone morphogenetic protein-7 (rhBMP-7) on new bone formation of alveolar ridge and absorption of alveolar ridge.DESIGN: Control experiment.SETTING: Department of Orthodontics, Jinan Stomatological Hospital;Shangdong Academy of Medical Sciences.MATERIALS: This study was conducted at the Shangdong Academy of Medical Sciences from June 2003 to December 2004. Totally 28 New Zealand white rabbits, of either gender, weighing 2 kg, were used in this study.METHODS: Animal extracted wound models were created on the rabbits.The mandibular left and right central incisor of the rabbits were removed.Two carriers containing BMP7 complex (40 μg/each) were implanted into the mandibular right central incisor (experimental group), two empty carriers containing only phosphate buffer solution(PBS) (40 μg/each) were implanted into the mandibular left central incisor (control group). The animals were sacrificed at postoperative 2, 4, 8 and 12 weeks. The specimen from the operated regions were harvested and observed by scanning electron microscope, and calcium content and alkaline phosphatase (ALP) activity were also measured.MAIN OUTCOME MEASURES: ① Result of scanning electron microscope (SEM). ② ALP activity and calcium content.RESULTS: ① The bone wound healing was 4-6 weeks earlier in the experimental group than in the control group . ② The ALP activity was significantly higher in the experimental group than in the control group week 2:(38.191±5.384, (19.821±2.084) μkat/g;week 4: (160.815±9.669), (126.709±1.634) μkat/g;week 8: (378.892±13.086),(225.212±1.884) μkat/g,P ＜ 0.01]. ③ The calcium was significantly higher in the experimental group than in the control group week 2:(5.592±0.110), (0.913±0.064) mg/g;week 4: (8.654±0.177), ( 1.702±0.071 ) mg/g;week 8: (25.326±0.287), (5.980±0.145) mg/g,P ＜ 0.01]CONCLUSION: BMP-7, which is expressed in the prokaryocyte, possesses good role in augmenting alveolar ridge and promoting the healing of alveolar wound.