聚左旋乳酸/磷酸三钙支架修复兔桡骨缺损成骨效果及降解速度的观察

背景组织工程支架是骨组织工程研究的重要部分,但目前还未开发出理想的骨组织工程支架.目的检验快速成型工艺制作的聚左旋乳酸/磷酸三钙Poly(L-lactic acid)/Tricalcium phosphate,PLLA/TCP]支架修复兔桡骨缺损的效果,寻找一种新型的生长因子载体. 设计随机对照实验研究.单位一所军医大学骨科研究所.材料实验于2001-05/2002-02在第四军医大学全军骨科研究所完成.对象为清洁级新西兰兔20只,雌雄不限,体质量(2 5±0.5)由第四军医大学实验动物中心提供.随机分为实验组10只,对照组10只.干预实验组和对照组分别采用复合牛骨形态发生蛋白(Bone morphogenetic protein,BMP)及单纯快速成型工艺制作的聚左旋乳酸/磷酸三钙(PLLA/TCP)支架修复兔桡骨15 mm缺损.主要观察指标主要结局①两组植骨材料光镜观察结果.②降解率.次要结局①大体观察.②影像学结果.③骨密度值.结果12周时实验组骨缺损愈合良好,X射线显示骨痂连续,有不同程度的部分塑形,支架降解率为39.6%,缺损部位骨密度值达到正常值的70%.各检测指标均优于对照组,对照组骨缺损未愈合.结论复合BMP的PLLA/TCP支架具有良好的成骨效果,可以很好的修复兔15 mm长骨骨缺损.

Observation of the repair of rabbit radial defect with poly (L-lactic acid)/tricalcium phosphate scaffolds and degradation rate

BACKGROUND: Scaffolds are an important part in bone tissue engineering. However, no perfect scaffolds have been developed for bone tissue engineering yet.OBJECTIVE: To evaluate the repair of rabbit radial defects by poly (L-lactic acid)/tricalcium phosphate(PLLA/TCP) scaffolds prepared by rapid prototyping(RP) technology so as to find a new carrier for growth factors.DESIGN: A completely randomized controlled study was conducted. SETTING: Orthopaedic institute of a military medical university.MATERIALS: The study was conducted in the General Orthopedic Institute,Fourth Military Medical University of Chinese PLA, from May 2001 to February 2002. Twenty clean New Zealand rabbits with body mass of(2.5 ±0. 5) kg for this study were obtained from the Experiment Animal Center of Fourth Military Medical University of Chinese PLA. The animals were divided into experiment group and control group with 10 rabbits in each group.INTERVETIONS: PLLA/TCP scaffolds prepared by RP technology and loaded with or without bovine bone morphogenetic protein (BMP) were used to repair the rabbit radial defects of 15 mm.MAIN OUTCOME MEASURES: Main outcomes: ① microscopic observation results of transplanted materials of the two groups; ② degradation rate of scaffolds. Secondary outcomes: ① gross observation; ② radiographic results; ③ bone density.RESULTS: At week 12, bone defect healing in experiment group was good. X-ray examination showed continuous bone callus and partial molding of different degrees. Degradation rate of scaffolds was 39.6%, and bone density in the defected part reached 70% of the normal level. All the indexes of experiment group were superior to those of control group, and no healing was found in the defected area in control group.CONCLUSION: PLLA/TCP scaffolds prepared by RP technology and loaded with bovine BMP can repair radial defects of 15mm in rabbits.