双相磷酸钙组织工程骨块重建股骨头内骨缺损的实验研究

目的 观察在体外构建的具有仿生结构的双相磷酸钙（biphasic calcium phosphate，BCP）组织工程骨块植入犬股骨头缺损内的骨再生情况及预防股骨头塌陷的效果。方法 以犬股骨头的松质骨样本Micro—CT（micro—computed tomography）图像为基础，提取其中的图像信息，利用三维凝胶叠层成形法制备出具有仿骨小梁结构的陶瓷支架。在体外利用诱导分化的自体骨髓间充质细胞与仿生BCP支架复合，构建组织工程骨块，将其植入10只犬的股骨头负重区骨缺损内；另取10只火作为对照组，在股骨头骨缺损区内打球植入自体松质骨粒，对比观察仿生BCP骨块的植入效果。结果 制备出的股骨头仿生BCP支架具有良好的三维空间结构，支架小梁具有一定的方向性，呈板状模型；细胞在支架表面大量生长。植入动物体内30周后，实验组火股骨头外形基本完整，新生骨质包绕支架小梁并沿支架表面生长，而对照组犬股坩头均出现不同程度的塌陷。结论 仿生BCP组织工程骨块具有良好的生物相容性，植入犬股骨头负曩区骨缺损后，能在一定程度上防止股骨头塌陷。

Reconstruct the bone defects of femoral head with structural oriented biphasic calcium phosphate scaffolds based tissue engineered bone

Objective To observe the effect of based biomimetic biphasic calcium phosphate(BCP)tissue engineered bone masses to repair the bone defects and prevent the collapse of femoral head in dogs.Methods Biomimetic BCP ceramic scaffolds was fabricated using three-dimensional(3D)gel-lamination technology according the micro-computed tomography(Micro-CT)information of cancellous bone of dogs' femoral heads.Tissue engineered bone masses were constructed by the combination of biomimetic BCP scaffolds and induced osteogenic bone marrow stromal cells(BMSCs)in vitro.In 10 dogs,tissue engineered bone was implanted into the bone defect on the weight-bearing area of femoral head.In the control group of another 10 dogs,autogenous cancellous bone chips were impressed into the bone defect on the weight-bearing area of femoral head.The gross appearance and regeneration of new bone were observed in 30 weeks postoperatively.Results The fabricated biomimetic BCP scaffolds had better 3D structure.The trabecular system of the scaffolds had some orientation along the weight-bearing line of femoral head and represented plate-like model.BMSCs grow flourishing on the surface of the scaffolds.After 30 weeks operatively,in the tissue engineered bone implanted dogs,the gross appearances of the femoral head were integrity and a great lot of new bone tissue wraps the trabecula of the scaffolds under microscope.In the control group,the mostly femoral heads were collapse gross appearance.Conclusion Tissue engineered biomimetic BCP had better biocompatibility and could prevent the collapse of femoral head after it is implanted into the bone defects of femoral head.