仿生多材料复合增强骨软骨支架的制造及性能研究

Fabrication and Performance Study of Biomimetic Multi-material Osteochondral Scaffold

针对关节面上大面积骨软骨缺损修复过程中软骨形态恢复和力学环境恢复困难的问题，设计并制造一种新型聚乙二醇（Polyethylene glycol, PEG）/聚乳酸（Polylactide, PLA）/β-磷酸三钙（β-Tricalcium phosphate,β-TCP）仿生多材料复合增强骨软骨支架。基于CT扫描数据重建的羊膝关节模型上进行仿生多材料骨软骨支架的结构设计，包括多孔定制结构和固定桩及仿生结构；以光固化成形技术与真空灌注工艺相结合制造了的多材料复合增强骨软骨支架，确定灌注温度220℃，真空度–0.08～–0.10 Pa。形貌观测表明真空灌注法能使PLA完全充满整个次级管道，力学试验发现复合材料支架的压缩强度（21.25 MPa ±1.15 MPa）是单管道多孔生物陶瓷支架（9.76 MPa±0.64 MPa）的2.17倍， PLA固定桩的剪切强度（16.24 MPa±1.85 MPa）是陶瓷固定桩（0.87 MPa±0.14 MPa）的18.7倍。因此，复合PLA的骨软骨支架具有显著的力学增强和固定能力，有望为大面积骨软骨缺损的修复提供新的治疗手段。

Both Cartilage restoration and mechanical environment recovery are still difficult issues for repairing large osteochondral defect, an innovative biomimetic PEG （polyethylene glyco） / PLA （Polylactide） / β-TCP （β-Tricalcium phosphate） multi-material reinforced osteochondral scaffold is designed and fabricated. On the basis of the sheep knee model reconstructed by CT scan data, biomimetic multi-material osteochondral scaffold is structurally designed. It includes a porous structure and PLA anchor and biomimetic cartilage structure. Integration technology of 3D printing and vacuum perfusion is carried out to fabricate multi-material reinforced osteochondral scaffold under the condition of temperature 220 ℃, vacuum degree are–0.08 to–0.10 Pa. The scaffold morphology observations show that the PLA can completely fill the secondary pipe by vacuum perfusion method, mechanical tests found that the compressive strength of the composite scaffolds （21.25 MPa± 1.15 MPa） is 2.17 times than that of a single-pipe porous ceramic scaffold （9.76 MPa± 0.64 MPa） ;shear test results show that the shear strength of PLA anchor （16.24 MPa ± 1.85 MPa） is 18.7 times than that of ceramic anchor （0.87 MPa± 0.14 MPa）. Therefore, mechanical strength and fixing performance of osteochondral scaffold has been significantly enhanced by perfusion of PLA, which provides a promising treatment for large osteochondral defects.