Dept. of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, USA.
Acta Biomater. 2010 Dec;6(12):4716-24. doi: 10.1016/j.actbio.2010.06.025. Epub 2010 Jun 30.
In this study, poly(vinyl alcohol) (PVA) hydrogels were reinforced with ultrahigh molecular weight polyethylene (UHMWPE) and PP fibers and evaluated as potential nondegradable meniscal replacements. An investigation of hydrogel and composite mechanical properties indicates that fiber-reinforced PVA hydrogels could replicate the unique anisotropic modulus distribution present in the native meniscus; the most commonly damaged orthopedic tissue. More specifically, fibrous reinforcement successfully increased the tensile modulus of the biomaterial from 0.23±0.02MPa without any reinforcement to 258.1±40.1MPa at 29vol.% UHMWPE. Additionally, the molecular weight between cross-links, bound water and the microstructure of the PVA hydrogels were evaluated as a function of freeze-thaw cycles and polymer concentration to lend insight into the processes occurring during synthesis. These results suggest the presence of multiple mechanisms as causes for increasing hydrogel modulus with freeze-thaw cycling, including hydrogen bonding between amorphous and/or crystalline regions, and the formation of highly concentrated regions of mostly amorphous PVA chains. It is possible that the formation of regions with highly concentrated amounts of PVA increases the load-bearing ability of the hydrogels.
在这项研究中，超高分子量聚乙烯（UHMWPE）和 PP 纤维增强了聚乙烯醇（PVA）水凝胶，并将其评估为潜在的不可降解半月板替代品。对水凝胶和复合材料力学性能的研究表明，纤维增强的 PVA 水凝胶可以复制天然半月板中存在的独特各向异性模量分布；这是最常见的受损骨科组织。更具体地说，纤维增强成功地将生物材料的拉伸模量从无任何增强的 0.23±0.02MPa 提高到 29vol.% UHMWPE 时的 258.1±40.1MPa。此外，还评估了 PVA 水凝胶的交联点间分子量、结合水和微观结构作为冷冻-解冻循环和聚合物浓度的函数，以深入了解合成过程中发生的情况。这些结果表明，随着冷冻-解冻循环，水凝胶模量增加的原因可能有多种，包括无定形和/或结晶区域之间的氢键以及主要为无定形 PVA 链的高浓度区域的形成。形成具有高浓度 PVA 的区域可能会增加水凝胶的承载能力。
