牡蛎壳／消旋聚乳酸复合人工骨修复兔桡骨缺损的实验研究

目的观察牡蛎壳／消旋聚乳酸复合人工骨（OPCB）修复兔桡骨节段性骨缺损的成骨能力，同时观察其在体内的生物相容性、降解情况，并评价其性能。方法应用热致相分离法（TIPS）分别制得OPCB及纯消旋聚乳酸（PDLLA）多孔材料；将27只成年新西兰白兔随机分成3组。制作1．2cm的双侧桡骨干缺损并植入上述两种材料。设立不植入任何材料的空白对照组。观察材料植入后动物的局部及全身反应。于术后6、12、侣周分别取材。作X线、大体标本及组织形态学观察，同时观察术后不同时期的组织反应、材料的降解、骨缺损的修复情况。结果OPCB及纯PDLLA植入动物体内无明显的局部不良反应，且OPCB材料修复骨缺损的能力明显强于纯PDLLA及空白对照组（P〈0．05）。术后18周时，植入OPCB材料的骨缺损基本修复，OPCB与宿主骨结合紧密；植入纯PDLLA材料的骨缺损部分修复；空白对照组则骨缺损断端只有少量骨生成。形成骨不连。同时OPCB材料植入后在6、12周分别可见吞噬有材料的巨噬细胞和多核巨细胞．18周时仍有部分复合材料未降解吸收。结论OPCB材料具备良好的生物相容性及骨缺损修复能力，是一种良好的骨组织工程修复材料。

Oyster shell/poly-DL-lactic acid composite in repairing radial bone defect of rabbits

Objective To evaluate the artificial bone substitute from oyster shell/poly-DL-lactic acid （PDLLA） in repairing radial bone defect of rabbits. Methods Thermally induced phase separation （TIPS） was employed to prepare the new composite artificial bone from oyster shell and poly-DL-lactic acid （OPCB）, and a high-porosity foam material made from PDLLA merely. A defect of 1.2cm in length was produced at both radii of 27 adult New Zealand rabbits which were divided into 3 groups randomly. In group A and B the defects were filled with OPCB and PDLLA respectively, while in group C （control） nothing was filled. The local and whole body responses of rabbits to the implants were observed after the operation; X-ray and histopathological exami- nations were performed when the rabbits were sacrificed at 6, 12 and 18 weeks after operations. Meanwhile, tissue response, degradation of the implants and defect repair were evaluated at the different time after the operation. Results No local adverse reaction was observed in all rabbits. The defect repairing ability of OPCB was significantly higher than that of PDLLA （P〈0.05）. The defects were almost completely repaired with OPCB, and partially repaired with PDLLA 18 weeks after operation; while the defects in group C remained nonunion. Numerous macrophage and multinuclear giant cells englobing repairing materials were detected at 6, 12 weeks; and remained at 18 weeks in OPCB group. Conclusion OPCB is a satisfactory artificial material for bone defect repair with favorable biocompatibility and effective defect repairing ＇ability.