Katta Jayanth K, Marcolongo Michele, Lowman Anthony, Mansmann Kevin A
School of Biomedical Engineering, Drexel University, 32nd and Chestnut Streets, Philadelphia, Pennsylvania 19104, USA.
J Biomed Mater Res A. 2007 Nov;83(2):471-9. doi: 10.1002/jbm.a.31238.
Many hydrogels have been proposed as articular cartilage replacements as an alternative to partial or total joint replacements. In the current study, poly(vinyl alcohol)/poly(vinyl pyrrolidone) (PVA/PVP) hydrogels were investigated as potential cartilage replacements by investigating their in vitro wear and friction characteristics in a pin-on-disk setup. A three-factor variable-level experiment was designed to study the wear and friction characteristics of PVA/PVP hydrogels. The three different factors studied were (a) polymer content of PVA/PVP hydrogels, (b) load, and (c) effect of lubricant. Twelve tests were conducted, with each lasting 100,000 cycles against Co-Cr pins. The average coefficient of friction for synovial fluid lubrication was a low 0.035 compared with 0.1 for bovine serum lubrication. Frictional behavior of PVA/PVP hydrogels did not follow Amonton's law of friction. Wear of the hydrogels was quantified by measuring their dry masses before and after the tests. Higher polymer content significantly reduced the wear of hydrogel samples with 15% PVA/PVP samples, showing an average dry polymer loss of 4.74% compared with 6.05% for 10% PVA/PVP samples. A trend change was observed in both the friction and wear characteristics of PVA/PVP hydrogels at 125 N load, suggesting a transition in the lubricating mechanism at the pin-hydrogel interface at the critical 125 N load.
许多水凝胶已被提议作为关节软骨替代品，以替代部分或全关节置换。在当前研究中，通过在销盘装置中研究聚乙烯醇/聚乙烯吡咯烷酮（PVA/PVP）水凝胶的体外磨损和摩擦特性，对其作为潜在软骨替代品进行了研究。设计了一个三因素可变水平实验来研究PVA/PVP水凝胶的磨损和摩擦特性。研究的三个不同因素为：（a）PVA/PVP水凝胶的聚合物含量；（b）载荷；（c）润滑剂的影响。进行了12次测试，每次测试针对钴铬销进行100,000次循环。与牛血清润滑时的0.1相比，滑液润滑时的平均摩擦系数低至0.035。PVA/PVP水凝胶的摩擦行为不符合阿蒙顿摩擦定律。通过测量测试前后水凝胶的干质量来量化其磨损。较高的聚合物含量显著降低了水凝胶样品的磨损，15% PVA/PVP样品的平均干聚合物损失为4.74%，而10% PVA/PVP样品为6.05%。在125 N载荷下，观察到PVA/PVP水凝胶的摩擦和磨损特性都出现了趋势变化，这表明在125 N的临界载荷下，销-水凝胶界面的润滑机制发生了转变。
