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聚乙烯醇(PVA)复合水凝胶作为半月板及软骨等长期承重植入体,在生理环境中的疲劳行为关系到植入体的持久性和稳定性。采用弥散增强的方法将纳米细菌纤维素(BC)均匀分散在PVA水凝胶基体中,制备了纳米BC/PVA复合水凝胶。在模拟体液(SBF)环境中,采用压缩疲劳过程分析、疲劳前后刚度变化分析及疲劳前后尺寸稳定性分析3种方法,测试和评价了复合水凝胶的抗疲劳性能和力学稳定性。结果表明:纳米BC/PVA复合水凝胶在模拟人体环境中具有良好的抗疲劳性能,能够满足体内植入物的抗疲劳性能需求;纳米BC的加入可以有效提升复合水凝胶的力学稳定性和抗疲劳性能,但随着纳米BC含量的进一步升高,复合水凝胶的抗疲劳性能有所减弱,当PVA与纳米BC质量比为30∶1时,纳米BC/PVA复合水凝胶疲劳前期与后期最大位移变化量最小(0.002mm),疲劳前后刚度变化最小(5.41%),且疲劳前后尺寸稳定性最强,变形量仅为0.427mm,抗疲劳性能达到最佳。
Polyvinyl alcohol (PVA) composite hydrogel is a long-term load-bearing implants such as meniscus and cartilage. The fatigue behavior in physiological environment is related to the durability and stability of implants. Nanometer BC / PVA composite hydrogel was prepared by dispersion-enhanced method by dispersing nanocellulose (BC) uniformly in PVA hydrogel matrix. In simulated body fluid (SBF) environment, fatigue resistance and mechanical stability of composite hydrogels were tested and evaluated by three methods: compression fatigue analysis, analysis of stiffness before and after fatigue and dimensional stability analysis before and after fatigue. The results show that nano-BC / PVA hydrogels have good anti-fatigue properties in simulated human environment and can meet the requirements of anti-fatigue properties of implants in vivo. The addition of nano-BC can effectively improve the mechanical stability of the composite hydrogels And anti-fatigue properties, but with the further increase of nano-BC content, the anti-fatigue property of the composite hydrogel is weakened. When the mass ratio of PVA to nano-BC is 30: 1, the nano-BC / PVA composite hydrogel fatigue The minimum displacement (0.002mm) in the early and late periods and the minimum stiffness (5.41%) before and after fatigue, the strongest dimensional stability before and after fatigue, the deformation amount of only 0.427mm, and the best fatigue resistance.