应用国产消旋聚乳酸载体复合rhBMP-2和hTGF-β1修复兔下颌骨缺损

Reconstruction of Rabbit Mandibular Defect with Poly-DL-Lactic Acid Carrier Combined with Recombined Human Bone Morphogenetic Pro tein-2and Human Transforming Growth Factor-a1

目的评价国产消旋聚乳酸(PDLLA)载体材料复合重组人骨形成蛋白-2和转化生长因子-β1(rhBMP-2/hTGF-β1)整复兔下颌骨骨缺损的能力和载体材料的性能。方法建立健康成年家兔下颌骨骨缺损动物模型,分别应用PDLLA/rhBMP-2、PDLLA/rhBMP-2/hTGF-β1、PDLLA/hTGF-β1复合材料作为实验组,单纯PDLLA载体材料和空白组作为对照组,整复下颌骨缺损;通过大体解剖学观察、CT扫描和三维重建等影像学检查以及组织病理学检查等方法进行研究。结果术后2周时,各组下颌骨缺损区长度无差异;术后4周和8周时,PDLLA/rhBMP-2、PDLLA/rhBMP-2/hTGF-β1、PDLLA/hTGF-β1复合材料植入组,下颌骨缺损区长度与单纯PDLLA材料和空白组有显著性差异(P<0.05),而复合材料各组间无差异。4～8周时,组织病理学检查显示:实验组可见大量分泌旺盛的成骨细胞,并有明显的新骨形成,PDLLA材料逐步降解。结论国产消旋聚乳酸载体材料复合骨形成蛋白-2和(或)转化生长因子-β1具有促进骨缺损修复的作用,PDLLA可作良好的载体材料。

Objective To evaluate the r econstructive functions and characters of domestic poly-DL-lactic acid(PDLLA)car rier combined with recombined human bone morphogenetic protein-2(rhBMP-2)and hum an transforming growth factor-a1for reconstruction of rabbit mandibular defect s.Methods Mandibular defects in animal model were made on36rabbit mandibles with the size of20mma1or PDLLA/hTGF-a1as experimental groups,18 mandibular defects(9rabbits)with single PDLLA carrier or empty as control.Macros copic,radiographic and histopathologic methods were used to estimate the reconst ructive functions of PDLLA/rhBMP-2,PDLLA/rhBMP-2/hTGF-a1and PDLLA/hTGF-a1.Re sults There was significant difference between the defect length of experimental and control groups after4to8weeks(P<0.05).Histopathological examination showed that there were more osteoblasts,new-formed osteoid and bone in the margin of de fect area in experimental group than in control.Meanwhile,PDLLA carrier became d egraded gradually.Conclusions PDLLA combined with rhBMP-2/hTGF-a1possessed the function of stimulating rabbit mandibular defect reconstruction while PDLLA car rier degraded gradually and released rhBMP-2and hTGF-a1growth factors.