新型生物复合材料聚乙烯醇／纳米羟基磷灰石＋聚己二酰己二胺修复关节软骨及软骨下骨缺损的生物力学研究

目的：探讨新型生物复合材料聚乙烯醇／纳米羟基磷灰石＋聚己二酰己二胺（Polyvinyl alcohol hydrogel／nano-hydroxyapatite＋polyamide66，PVA／n-HA＋PA66）修复兔关节软骨及软骨下骨缺损的生物力学性能。方法：实验于2006-01/2007-05在四川大学华西医院骨科组织工程实验室完成。①通过原位合成技术及冷冻．融合循环方法制备PVA／n-HA＋PA66，并检测材料体外力学性能。②在兔股骨关节面上打孔，包括关节表面软骨和软骨下骨，制成关节软骨缺损的模型。将PVA／n-HA＋PA66复合材料植入兔膝关节，对侧肢体打孔作空白对照组或单纯PVA植入，分别于植入12，24周后行局部组织学切片观察，扫描电镜观察，生物材料体内力学性能测试。结果：36只兔全部进入结果分析。①上层材料在100mm／min拉力状态下，抗拉强度为3．42MPa，下层材料的抗拉强度为6．33MPa。上层材料在3mm／min的压力强度下，抗压强度为3．12MPa。下层材料的抗压强度为5．3MPa。②生物复合材料植入动物体内12，24周，下层材料中有骨组织长入，上层材料与下层材料紧密连接；生物复合材料在5mm／min的冲击强度下，其抗冲击强度在植入12周时已达正常松质骨抗冲击强度。结论：新型生物复合材料PVA／n-HA＋PA66修复兔关节软骨及软骨下骨缺损具有良好的生物力学性能。

Biomechanics study of polyvinyl alcohol hydrogel/nano-hydroxyapatite ＋ polyamide66 in repair of articular cartilage and subchondral bone defects

AIM： To observe mechanical properties of a new type of composite material polyvinyl alcohol hydrogel/nano-hydroxyapatite ＋ polyamide66 （PVA/n-HA＋PA66） on repair of rabbit knee joint articular cartilage and subchondral bone defects. METHODS： Experiments were performed at the Tissue Engineering Laboratory, Department Orthopedics, West China Hospital, Sichuan University from January 2006 to May 2007. 1.New type biological composite materials （PVA/n-HA＋PA66） were prepared by in situ synthesis technique and freezing-fusing circulation method. Mechanical property was measured. 2.The animal models of defect of articular cartilage and subchondral bone were made up by drilling a hole and PVA/n-HA＋PA66 were implanted into the rabbit knees. Drilling a hole at opposite side was performed as controls or only implanting PVA into the hole. The histological evaluation, scanning electron microscope （SEM） and mechanical properties in vivo were performed at weeks 12 and 24. RESULTS： All 36 rabbits were included in the final analysis. 1.The upper layer material strength of resisting-draw was 3.42 MPa and the lower layer was 6.33 MPa under 100 mm/min pulling force. The strength of resisting press was 3.12 MPa and the lower layer material strength of resisting press was 5.3 MPa under 3 mm/min pressing force. 2.At weeks 12 and 24 bone tissue were found growing into lower layer materials. The upper layer materials connected tightly with the lower layer materials. The strength of resisting lash of composite materials reached to the strength level of normal bone＇s resisting lash at 12 weeks under the state of 5 mm/min lashing force. CONCLUSION： The new type biological composite materials PVA/n-HA＋PA66 have good biomechanics properties on repair of rabbit knee joint articular cartilage defects and subchondral bone defects.