三维多孔D,L-PLA骨替代材料的实验研究

Experimental study of bone substitute made of 3-D porous D,L-PLA

目的:探讨三维多孔D,L-PLA骨替代材料降解特点及骨修复能力。方法:体外实验采用浇铸盐析技术制成三维多孔D,L-PLA材料,将其放置于PH值为7的双蒸水中观察其降解过程中pH值、分子量、重量、生物力学性能的变化。体内实验将20只兔子40只前肢制造桡骨10mm骨缺损,分别给予植入材料或作为空白对照,在2、4、8、12周取材做大体观察、组织形态学观察、X线观察、生物力学检测。结果:该材料在降解过程中重量及生物力学的变化滞后于分子量变化,0～4周时变化较小。12周时pH值为2.94,此时植入材料者骨缺损区已修复,空白对照者骨缺损两端骨髓腔闭合骨缺损区无骨长入。结论:该材料的结构及降解特点有利于骨长入,作为骨替代品具有良好的应用前景。

Objective: To investigate the degradation characteristics and ability of bone repair of 3-D porous D,L-PLA bone substitute.Methods: A particulate-leaching method was developed to prepare 3-D porous D,L-PLA in vitro, and the material were put into water to measure the pH, molecular weight, weight and biomechanics at 2 weeks, 4 weeks, 8 weeks and 12 weeks respectively. Twenty rabbits with 10 mm bilateral radius bone defect were randomly planted with the material of D, L-PLA or nothing (as control group) . The samples were examined by gross, X-ray, histomorphology and the biomechanics in 2,4,8 and 12weeks. Resuts: During the degradation, the change of weight and biomechanics lagged the change of molecular weight. At 12 weeks, pH was 2.94. And at 12 weeks, bone defect healed and no bone regenerations were observed in control group. Conclusion: The degradation characteristics and stuctures of 3-D porous D,L-PLA are favorable for bone regeneration, and it would be a good bone substitute.