Mechanically Reinforced Gelatin Hydrogels by Introducing Slidable Supramolecular Cross-Linkers
Mechanically Reinforced Gelatin Hydrogels by Introducing Slidable Supramolecular Cross-Linkers
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DOI：
10.3390/polym11111787
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发表时间：
2019-11-01
期刊：
影响因子：
5
通讯作者：
Yui, Nobuhiko
中科院分区：
文献类型：
--
作者：
Lee, Dae Hoon;Tamura, Atsushi;Yui, Nobuhiko
用于损伤组织再生的组织替代物通常需要坚韧的机械性能，因为这些替代物必须能够承受拉伸引起的外部物理力。明胶是一种由胶原蛋白衍生而来的生物聚合物，是一种生物相容性和细胞黏附材料，因此被广泛用作生物材料的组成部分。然而，由于明胶水凝胶的力学性能不足，其作为组织替代物的应用受到限制。化学交联法是一种很有前途的改善水凝胶力学性能的方法。我们研究了明胶水凝胶与羧基修饰聚轮烷(PRXs)化学交联的可能性，以改善拉伸和韧性等力学性能。将明胶水凝胶与在PRX中穿线的α-CD进行交联，可以使交联点自由移动，从而潜在地改善机械性能。与传统的化学交联剂1-乙基-3-(3-二甲氨基丙基)碳二亚胺(EDC)/N-羟基丁二酰亚胺(NHS)相比，用PRX交联的明胶水凝胶的延伸性和韧性略高于常规化学交联剂的水凝胶。此外，与传统的交联水凝胶相比，在水合状态下经过反复拉伸和松弛循环后的明胶水凝胶的滞后损失也得到了显著的改善。有人认为，明胶水凝胶与PRXS的自由移动交联点可以减弱应力集中。因此，与PRX交联的明胶水凝胶将提供优异的力学性能，作为暴露在持续外力下的生物相容组织替代物。
Tough mechanical properties are generally required for tissue substitutes used in regeneration of damaged tissue, as these substitutes must be able to withstand the external physical force caused by stretching. Gelatin, a biopolymer derived from collagen, is a biocompatible and cell adhesive material, and is thus widely utilized as a component of biomaterials. However, the application of gelatin hydrogels as a tissue substitute is limited owing to their insufficient mechanical properties. Chemical cross-linking is a promising method to improve the mechanical properties of hydrogels. We examined the potential of the chemical cross-linking of gelatin hydrogels with carboxy-group-modified polyrotaxanes (PRXs), a supramolecular polymer comprising a poly(ethylene glycol) chain threaded into the cavity of alpha-cyclodextrins (alpha-CDs), to improve mechanical properties such as stretchability and toughness. Cross-linking gelatin hydrogels with threading alpha-CDs in PRXs could allow for freely mobile cross-linking points to potentially improve the mechanical properties. Indeed, the stretchability and toughness of gelatin hydrogels cross-linked with PRXs were slightly higher than those of the hydrogels with the conventional chemical cross-linkers 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS). In addition, the hysteresis loss of gelatin hydrogels cross-linked with PRXs after repeated stretching and relaxation cycles in a hydrated state was remarkably improved in comparison with that of conventional cross-linked hydrogels. It is considered that the freely mobile cross-linking points of gelatin hydrogels cross-linked with PRXs attenuates the stress concentration. Accordingly, gelatin hydrogels cross-linked with PRXs would provide excellent mechanical properties as biocompatible tissue substitutes exposed to a continuous external physical force.