聚DL-乳酸/羟基磷灰石复合材料修复长骨缺损的实验研究

目的 :评价羟基磷灰石 (HA)复合聚DL 乳酸 (PDLLA )制备的材料体内成骨能力。方法 :将PDLLA和PDLLA/HA( 2 0wt % )材料采用盐结晶颗粒沥滤法制成三维多孔材料 ,45例 1cm兔桡骨去骨膜缺损分为三组 ,分别植入 2种材料和作空白对照 ,术后 2 ,4,8,12周行X线、组织学及扫描电镜观察骨生成状况 ,8、12周行生物力学测试 (三点折弯强度 )。结果 :泡沫状PDLLA/HA ( 2 0wt % )材料比纯PDLLA成骨更好 (P <0 .0 5 ) ,实验组与对照组相比差异有显著性 (P <0 .0 5 )。结论 :PDLLA具有良好的生物相容性 ,制成多孔状具有较好的骨传导性能 ,HA( 2 0wt % )的加入促进了多孔PDLLA的骨传导能力 ,提高了骨生成的质量。PDLLA/HA( 2 0wt % )复合材料是一种有临床应用前景的骨移植材料。

Experimental study of Poly-DL-Lactide/ Hydroxyapatite composite repair bone defect

Objective: To investigate the effect on bone formation of PDLLA/HA composites. Methods: High-porosity foams of PDLLA and PDLLA/HA (20wt%) were fabricated by a solvent-casting particulate-leaching technique with NaCl as the leachable component. 45 rabbits which had been practiced 1.0 cm radial diaphyseal defects with complete resection of periosteum were divided into 3 groups in random. Two groups were repaired respectively with PDLLA and PDLLA/HA , while the third group was taken as the control. The specimens were harvested at 2, 4, 8, 12 weeks after operation. The samples were examined by X-ray, histology and scanning electronic microscope (SEM) to evaluate the effectiveness of defect repair. At 8, 12 weeks after implantation of grafts, the biomechanical testing (bending strength) was used to study the quality of bone formation. Results: The PDLLA/HA (20wt%) composite stimulated more bone formation and has higher bending strength than the single PDLLA ( P <0.05). The former two experiment groups had significantly higher bone formation than the control group in every stage of postimplantation (P <0.05). Conclusions: PDLLA has good biocompatibility and osteoconductibility when fabricated into porous material, moreover, the PDLLA/HA (20wt%) composite has better osteoconductibility and can improve the quality of novel bone formation. A composite of PDLLA/HA (20wt%) is a new valuable bone implant material.