Meng Lihui, Hu Yanru, Li Wenchao, Zhou Zilin, Cui Shuojie, Wang Meng, Chen Zebin, Wu Qingzhi
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China.
Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, P. R. China.
ACS Appl Mater Interfaces. 2024 Oct 2;16(39):53007-53021. doi: 10.1021/acsami.4c13362. Epub 2024 Sep 20.
Although poly(vinyl alcohol) (PVA) hydrogel has high elasticity and is suitable for cartilage tissue engineering, it is difficult to have both high strength and toughness. In this study, a simple and universal strategy is proposed to prepare strong and tough PVA hydrogels by in situ forming nanofibers on the original network structure induced by a molecular chain rearrangement. Quenching-tempering alteratively in ethanol and water several times is carried out to strengthen PVA hydrogels (PVA-Et hydrogels) due to the advantages of noncovalent bonds in adjustability and reversibility. The results show that, after three quenching-tempering cycles, PVA-Et hydrogel with water content up to 79 wt % shows comprehensive improved mechanical properties. The compression modulus, tensile modulus, fracture strength, tensile strain, and tear energy of the PVA-Et hydrogel are 270, 250, 260, 130, and 180% of the initial PVA hydrogel, respectively. The improved mechanical properties of the PVA-Et hydrogel are attributed to the strong cross-linked PVA chains and hydrogen bond-reinforced nanofibers. This study not only provides a simple and efficient solution for the preparation of strong and tough polymer scaffolds in tissue engineering but also provides new insights for understanding the mechanism of improving the mechanical properties of polymer hydrogels by adjusting the molecular structure.
尽管聚乙烯醇（PVA）水凝胶具有高弹性且适用于软骨组织工程，但其难以同时具备高强度和高韧性。在本研究中，提出了一种简单通用的策略，通过在分子链重排诱导的原始网络结构上原位形成纳米纤维来制备强韧的PVA水凝胶。由于非共价键在可调节性和可逆性方面的优势，在乙醇和水中交替进行多次淬火回火处理以增强PVA水凝胶（PVA-Et水凝胶）。结果表明，经过三个淬火回火循环后，水含量高达79 wt%的PVA-Et水凝胶的力学性能得到全面改善。PVA-Et水凝胶的压缩模量、拉伸模量、断裂强度、拉伸应变和撕裂能分别是初始PVA水凝胶的270%、250%、260%、130%和180%。PVA-Et水凝胶力学性能的改善归因于强交联的PVA链和氢键增强的纳米纤维。本研究不仅为组织工程中强韧聚合物支架的制备提供了一种简单有效的解决方案，也为通过调整分子结构来理解改善聚合物水凝胶力学性能的机制提供了新的见解。
