聚乙烯醇缩丁醛对三维联通纳米氧化锆骨组织工程支架压缩强度的影响

Polyvinyl butyral improves the properties of 3-dimensional nano-zirconia porous scaffolds for bone tissue engineering

目的：既往制备出的纳米氧化锆骨组织工程支架具有良好三维联通性但成型率和压缩强度均未达到理想水平。文中在浆料的制备过程中加入聚乙烯醇缩丁醛（ Polyvinyl butyral ， PVB）作为分散剂，期望制备出性能更稳定的浆料，并同时探索PVB的最佳添入量，以达到优化支架性能的目的。方法制备0～0．3wt％ PVB含量的纳米氧化锆乙醇水基浆料，利用沉降反应、万能试验机测试压缩强度以及扫描电镜观察研究分析PVB的添加效果。结果沉降实验显示不添加PVB （添加去离子水）的氧化锆浆料分层明显，上层为上清液，下层为白色沉淀，添加了0～0．3wt％ PVB的氧化锆浆料上下层均无明显界限，上层为白色混悬液，下层为白色沉淀。0．2wt％ PVB 氧化锆粉体沉降实验分层最不明显，其支架压缩强度为（0．324±0．030）MPa，明显高于去离子水和其他浓度PVB支架（P＜0．01）；以往使用的氧化锆水基浆料制作的支架压缩强度为（0．109±0．021）MPa，明显低于不同浓度PVB支架（P＜0．05），不同浓度PVB支架（0．2wt％ PVB除外）压缩强度差异无统计学意义（P＞0．05）。 SEM观察结果显示，0．2wt％PVB所制作的支架表面裂纹最少且分布稀疏，其余不同浓度PVB浆料制作的支架表面均有不同程度的缺陷，裂纹大而深。结论 PVB添加后能明显改善氧化锆浆料的稳定性，并能提高氧化锆支架的压缩强度，可以满足体内成骨模型实验研究。

Objective The nano-zirconia scaffolds we previously prepared had a good 3-dimensional （ 3D ） connectivity but did not achieve the ideal sintering rate and compressive strength .The objective of this study was to explore the enhancing effect of polyvinyl butyral （ PVB） as a dispersant on the compressive strength of 3D nano-zirconia porous scaffolds for bone tissue engineering . Methods We prepared the slurry containing different concentrations of PVB and ana-lyzed the improving effect of PVB on the mechanical properties of the scaffolds by sediment experiment , compressive strength test and scan-ning electron microscopy . Results The sediment experiment showed no significant stratification in the slurry with 0.2wt%PVB, white suspension in the upper layer and white precipitate in the lower layer , with a significantly higher compressive strength of the scaffold （[0.324 ±0.030] MPa） than that of the scaffold prepared by adding other concentrations of PVB to the slurry （P〈0.01）.And the compressive strength of the scaffold constructed by adding no dispersant （[0.109 ±0.021] MPa） was remarkably lower than that of the scaffold constructed by adding PVB to the slurry （P〈0.05）.Scanning electron microscopy demonstrated that the scaffold prepared by adding 0.2wt%PVB to the slurry had a complete porous structure with the fewest and most sparsely distributed surface cracks as compared with other PVB concentration groups . Conclusion PVB can signifi-cantly improve the stability of zirconia slurry , enhance the compressive strength of the nano-zirconia porous scaffold , and make the scaf-fold more applicable to bone tissue engineering .