聚乳酸及其复合物修复下颌骨缺损的实验研究

目的　聚乳酸与骨形成蛋白复合 ,研究该材料修复颌骨缺损的能力 ,探讨聚乳酸作为骨形成蛋白载体的有效性。方法　 18只日本大耳白兔 ,随机分组 ,在双侧下颌骨体部形成 12 m m× 6 mm的缺损 ,分别植入聚乳酸 -人骨形成蛋白 - 2复合物 (PL A- rh BMP- 2 )、单纯聚乳酸 (PL A) ,于 2、4、8、12周分批处死。通过 X线、组织学染色等方法进行观察。结果　 PL A- rh BMP- 2植入组于术后 2周 ,缺损区部分新骨形成 ;术后 8周 ,大片新骨形成并开始改建 ,术后 12周 ,PL A大部分降解 ,由骨组织修复。结果优于对照组。结论　 PL A可作为 BMP的有效载体 ,PL A-rh BMP- 2是良好的颌骨缺损修复材料

THE EXPERIMENTAL STUDY OF REPAIRING THE MANDIBULAR BONE DEFECT USING PLA-rhBMP-2

Purpose A new synthetic material consists of Polylac tic acidPLA] and recombinant human bone morphogenetic protein-2PLA-rhBMP -2]. The capacity of repairing bone defect of biodegradable PLA and the effica cy of PLA as a carrier for bone morphogenetic protein BMP] are determined wit h detecting the osteogenetic process. Materials and Methods Eighteen rabbits were picked up and divided i nto three groups randomly. The defects of 12mm×6mm size were made at bilateral mandibul ar edges. PLA-rhBMP-2, PLA were implanted in the defect respectively. The 18 r abbits were killed at 2,4,8 and 12 weeks after implanting. The sample was analyz ed by the methods of X-rays and histological examination. Results After 2 weeks, the new bone began to form in the defects. A fter 8 weeks, bulk bone could be obviously observed. After 12 weeks, most of the PLA in the defects were already biodegraded. The defects were restored with n ew bone. The results in PLA-rhBMP-2 group were better than those of other grou ps. Conclusions PLA could be a promising carrier for BMP. PLA-rhBM P-2 has also been considered a better biodegradable material for repairing mand ibular defect.