磷酸镁/聚多巴胺涂层3D打印多孔钛材料的体内成骨效应研究

摘要

目的 制备磷酸镁(MP)/聚多巴胺(PDA)涂层3D打印多孔钛材料并探讨其体内成骨效应.方法 利用多巴胺自聚合反应及溶胶-凝胶技术在多孔钛(pTi)材料表面制备MP/PDA复合涂层,通过扫描电镜观察材料的表面形貌.30只新西兰兔建立双侧股骨外侧髁骨缺损模型,根据植入材料的不同随机分为3组(n=10):A组植入MP/PDA-pTi复合材料,B组植入单纯pTi材料,C组未植入材料.分别于术后1d,术后4、8、12周行CT扫描,术后12周取材,行大体观察、Micro-CT检测及组织学观察.结果 扫描电镜示MP/PDA涂层在pTi材料表面均匀涂覆,表面粗糙.术后12周大体观察及CT扫描可见A组骨缺损基本完全修复;B组缺损表面可见局部凹陷;C组骨缺损未修复.Micro-CT结果显示:A组的骨体积分数(28.27±4.78)％显著高于B组(23.34±7.20)％和C组(10.34±3.27)％,差异有统计学意义(F=60.233,P＜0.01).组织学结果显示:A组的新生骨面积百分比(32.23±3.69)％显著高于B组(19.55±4.13)％和C组(5.05±2.63)％,差异有统计学意义(F=295.488,P＜0.01).结论 pTi材料表面MP/PDA涂层改性处理可以显著提高pTi材料的骨修复及骨整合能力.%Objective To evaluation the bone regeneration performance of 3D printed porous titanium biomaterials with magnesium phosphate (MP)/poly dopamine (PDA) coating in vivo.Methods Porous titanium (pTi) scaffolds underwent surface modification with MP/PDA coating by dopamine self-polymerization and sol-gel techniques.The surface modification was characterized by scanning electron microscopy.Animal models of bone defects were created in 30 New Zealand rabbits by drilling holes in bilateral femur lateral condyles,and the rabbits were randomly divided into 3 groups (n =10 in each group):group A treated by filling with MP/PDA-pTi,group B treated by filling with pTi,group C with the defects untreated.CT was performed at 1th day,4th,8th and 12th week after operation.The specimens were harvested at 12th week after operation,which were then evaluated by gross observation,Micro-CT and histological examinations.Results The scanning electron microscopy examination revealed that the MP/PDA coating was uniformly deposited on the surface of pTi,with rough surface.Gross observation and CT examination at 12th week postoperatively revealed that defects were being healed completely in group A;bony connection was not achieved in group B;defects were not repaired in group C.Micro-CT revealed that the bone volume fraction values were found to be significantly greater in group A (28.27 ± 4.78) ％ compared with group B (23.34 ± 7.20) ％ and group C (10.34 ± 3.27) ％ (F =60.233,P ＜ 0.01).Histological examination revealed that the percentages of bone regeneration values were found to be significantly higher in group A (32.23 ±3.69)％ compared with group B (19.55 ±4.13)％ and group C (5.05 ±2.63)％ (F =295.488,P ＜ 0.01).Conclusion Compared with pure pTi scaffolds,MP/PDA-pTi scaffolds possess a better capacity of osteogenesis and osteointegration.