纳米细菌纤维素/聚乙烯醇复合水凝胶在模拟体液中的疲劳行为

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。

Fatigue behavior of nano bacterial cellulose/poly(vinyl alcohol)composite hydrogels in simulated body fluid

As long time load-bearing implants such as meniscus and cartilages, the fatigue behavior of poly(vinyl alcohol) (PVA) composite hydrogel in physical environment relates to persistence and stability of the implants. The nano bacterial cellulose (BC) was dispersed evenly into PVA hydrogel matrix to prepare nano BC/PVA composite hydrogels by method of dispersive strengthening. To investigate and evaluate the anti-fatigue property and mechanical stability of composite hydrogels in simulated body fluid (SBF) environments, three methods including compression fatigue process analysis, stiffness variation analysis and dimensional stability analysis before and after fatigue were used.The results show that the nano BC/PVA composite hydrogels have excellent anti-fatigue property in simulated body environments, which can meet the requirements of anti-fatigue property for implant in body. By adding nano BC, the mechanical stability and anti-fatigue property of composite hydrogels are improved effectively, but as the addition of nano BC increasing further, the anti-fatigue property of composite hydrogels is reduced. When the mass ratio of PVA to nano BC is 30:1, the nano BC/PVA composite hydrogels show the least maximum displacement increment (0.002 mm), the minimum change of stiffness (5.41%) and the best dimensional stability before and after fatigue, the deformation amount is merely 0.427 mm, and the fatigue property is the best.