PLLA/珍珠层粉复合支架修复兔骨缺损的实验研究

摘要

Objective:To prepare PLLA/pearl layer powder composite scaffolds in repairing bone defects in vivo degradation and biocompatibility, provideing the experimental basis for clinical application of bone repair.Method:Using the freeze drying method to prepare PLLA/pearl layer powder composite scaffolds,its shape characterization was measured by SEM,bracket of pore structure was measured by mercury injection apparatus,scanning method to collect data at low pressure mode.To choose 24 healthy adult New Zealand white rabbit as experimental objects,the selection of the rabbits were randomly divided into four groups:group A(PLLA scaffold materials),group B(PLLA/pearl layer stent group),group C(tiny particles bone group),group D(blank group).Through the establishment of middle 1 cm in bilateral radius as a bone repair bone defect model,to detect different composite materials stents defect.In different cages,for three consecutive days to give gentamicin to prevent infection and after 4,8,12 weeks to go imaging,histology,bone mineral density,graded by Lane-sandhu, and valuated of composite scaffolds into bone.Result:PLLA/pearl layer powder composite scaffold was prepared successfully,scanning were angled trapezium of the porous structure,we could see pearl layer powder evenly distributed on the hole wall and the edge, scaffold porosity basically were all between 88%-93%. Dual-energy X-ray absorptiometry combined postoperative we could see that after 4,8 weeks group B composite support score by X-ray and histological grading were slightly lower than those of group C(P<0.05),after 12 weeks there was no statistical significance between group B and group C(P>0.05).Conclusion:The self-made PLLA/pearl layer powder composite scaffolds has a good osteogenesis effect, and the results are provided the basis for clinical application.%目的：研制PLLA/珍珠层粉复合支架在修复骨缺损体内降解与生物相容性，为临床应用骨修复提供实验依据。方法：采用冷冻干燥法制备PLLA、PLLA/珍珠层粉支架，用SEM测定其形态表征，用压汞仪测定支架的孔结构。选择24只健康成年新西兰大白兔为实验对象，将选取的24只兔子随机分为四组：A组：PLLA支架材料组，B组：PLLA/珍珠层支架组，C组：微小颗粒骨组；D组：空白组。利用牙钻制成双侧桡骨中段1 cm骨缺损作为骨修复模型，将不同复合支架材料植入缺损处。与术后4、8、12周行影像学、组织学、骨密度检测，并行Lane-sandhu评分，评价复合支架材料的成骨性。结果：成功制备出PLLA/珍珠层粉复合支架，扫描电镜支架断层面呈现出阶梯多孔结构，可见珍珠层粉均匀的分布在孔壁和边缘上，其支架材料的孔隙率在88~93%，双能X射线骨密度仪结合术后X线片得出：术后4、8周B组X线评分和组织学评分略低于C组(P<0.05)，12周两组X线和组织学评分比较差异均无统计学意义(P>0.05)。结论：PLLA/珍珠层支架具有良好的成骨作用，该结果为PLLA/珍珠层支架的临床应用提供了基础。