多孔β-TCP用于构建长骨组织的实验研究

探索新型的多孔β-磷酸三钙(β-TCP)作为组织工程骨支架材料的应用效果。分别应用单纯β-TCP(对照组)和骨髓间质干细胞（bone marrow stem cells, BMSCs）、β-TCP复合物(实验组)修复狗尺骨2cm的骨缺损，术后通过X光片、核素扫描、大体观察和组织学观察判断长骨骨缺损的修复效果。X片观察：3月时，实验组尺骨缺损由内植物较好的桥接，内植物边缘模糊，管腔及内植物与缺损断端之间有新生骨形成；对照组尺骨缺损处的内植物明显变形，出现密度不均的裂解颗粒，其与缺损断端连接处有新生骨形成。6月时，实验组尺骨缺损被伴有骨髓腔的新生骨连接，有皮质骨形成；对照组尺骨缺损被高密度影连接，没有骨髓腔和明显皮质骨形成，尺骨远端直径明显细于实验组。核素扫描的延迟相骨显像：1月和2月时两组之间有显著性差异，3月时两组之间无显著性差异。大体观察：3月时可见，对照组尺骨直径明显小于实验组，实验组的骨缺损处新生物的体积明显大于对照组；对照组的内植物周围有纤维组织紧密包裹，难于分离。6月时可见，实验组新生骨色泽红白相间，明显已被塑形；对照组新生骨体积、形状不完整。HE观察：3月时，实验组β-TCP的孔隙中，可见新生骨在表面贴附生长；对照组β-TCP的孔隙中有类骨质形成，充填着大量核深染的巨核细胞和毛细血管。6月时，两侧的β-TCP都完全消失，都有新生骨形成，但对照组新生骨量和骨结构明显差于实验组。复合骨髓基质干细胞的多孔β-TCP能够修复长骨骨缺损。

Experimental Study of Porous TCP to Generate Tissue-engineered Long Bone

To study bone-forming of a new kind of porous beta-TCP as the scaffold for tissue-engineering, defects at the mid-portion of the left and right ulna were created in dog, the defects were repaired with beta-TCP cylinder coated with BMSCs, and beta-TCP cylinders alone as control. X-rays showed the defects were better bridged by the replant with obscure edge and new bone formed in the canal and at the interface in experimental group after three month of operation, whereas in control group, the replants were obviously deformed into dissociated granule with unequal density with only little new bone formed at the interface. After six month, the defects were bridged by new bone with osteodermatous cavum medullare ossium, but in control group, the defects were bridged by high density in radiography without osteodermatous cavum medullare ossium, the diameter of the ular was obviously less than experimental group. There were significant differences between both groups at month one and two in the development pattern through radionuclide observation. By gross, the diameter of ular was smaller in control group than in experimental at month three, and the replants in control group was difficult to detach from the fibroid tissue around it, but in experimental group, there was much more new bone formation, and the surface was rough for the compound of new bone and beta-TCP undegraded completely. The new bone in experiment had been obviously remodeled at month six, but at this moment, the new bone was of infirmity in volume and form. HE staining of three months demonstrated new bone adhered to the surface on the core of beta-TCP in experimental group, but in control group, at the same place, osteoid was observed with much megacayocytes and capillaries. At month six, beta-TCP disappeared completely with new bone formed in both groups, but the volume and structure of the bone was better in experimental group than in control group. From this study it is concluded that the porous beta-TCP can be combined with BMSCs, and the combination could generate new bone to repair long bone defect.