聚乳酸-聚乙二醇的制备及骨修复实验研究

目的研究聚乳酸-聚乙二醇（PLA—PEG）共聚物作为细胞因子骨形态发生蛋白（BMP）、碱性成纤维细胞生长因子（bFGF）的载体修复下颌骨缺损的效果。方法制备多孔PLA—PEG共聚物并对其进行表征。将PLA—PEG／BMP（实验组1）、PLA—PEG／BMP／bFGF（实验组2）和PLA—PEG（对照组）分别植入27只雄性新西兰白兔的下颌体部骨缺损处。术后、2周、4周和8周，对实验标本的成骨状况进行大体、X线、组织学：扫描电子显微镜观察及计算机图像分析。结果实验期间各组成骨活跃。2周时实验组2成骨量最多，实验组1其次，对照组最少，差异在统计学上有显著性意义（P〈0．05）；4周时实验组2成骨量最多，其余两组成骨量差异不大（P〉0．05）；8周时各组的成骨量的差异在统计学上无显著性意义（P〉0．05）。结论新型的PLA—PEG共聚物呈现良好的生物相容性和骨引导性，是BMP和bFGF的良好载体。

The study of the copolymer of PLA and PEG on the repair of rabbit mandibular defect

Objective To evaluate the effect of the new PLA-PEG and the composite of PLA-PEG,bone morphogenetic protein (BMP) and basic fibroblast growth factor (bFGF) on the regeneration of the rabbit mandibular defects.Methods The porous PLA-PEG was prepared by ring-opening polymerization and solvent-casting/particle -leaching.PLA-PEG (control group),PLA-PEG/BMP (experimental group A) and PLA-PEG/BMP/bFGF (experimental group B) were respectively implanted into 27 rabbit mandibular defects.Two,four and eight weeks after operation,the rabbits were sacrificed and the specimens examined by naked eyes,X-ray,optical microscope, computerized image analysis and SEM.Results At the 2~(nd) week the regenerated bone in the experimental group B was significantly more than that in the experimental group A,trailed by control group.At the 4~(th) week the new bone in the experimental group B was more in size,no statistically significant difference of the new bone between the other two groups.At the 8th week there was no statistically significant difference among the three groups with regard to the bone regeneration.Conclusion This new PLA-PEG possesses sound biocompatibility and osteoconduetivity,which will have more positive effect on bone regeneration when combined with BMP.And bFGF can synergistically enhance the bone regeneration with PLA-PEG and BMP.This new biomaterial is safe and reliable in bone regeneration.