Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065, China.
Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry, Beijing Technology and Business University, Beijing 100048, China.
Int J Biol Macromol. 2021 Jul 1;182:1259-1267. doi: 10.1016/j.ijbiomac.2021.05.057. Epub 2021 May 13.
Dynamic covalently crosslinking (DCC) hydrogels can mimic extracellular matrix and have the functions such as self-healing, self-adapting, and shape memory. The DCC keratin hydrogels based on thiol group-disulfide bonds exchange strategy have no reports so far as we know. Herein, inspired by the rich content of the intramolecular disulfide bonds and free thiol groups in the keratins extracted by reducing agents, we report a simple thiol-disulfide bonds exchange strategy for preparing the DCC keratin hydrogels. While the pH value of the keratin solution extracted by reducing agents was adjusted to 9.5-10.0, the keratin hydrogels showed the characteristic with injectability, self-healing, self-adapting, biocompatibility, and redox-responsive capacity. The extracted type II neutral/alkali keratin plays a critical role in imparting the keratin hydrogels with the reversibility behaviors due to that the keratins could build dynamic covalent bonds through thiol oxidation and disulfide exchange reactions in alkali conditions. This strategy provides an inspiration for forming DCC keratin hydrogel by avoiding the extra introduction of chemical crosslinking agents.
动态共价交联 (DCC) 水凝胶可以模拟细胞外基质，并具有自修复、自适应和形状记忆等功能。基于巯基-二硫键交换策略的 DCC 角蛋白水凝胶目前尚未有报道。受还原剂提取角蛋白中丰富的分子内二硫键和游离巯基含量的启发，我们报道了一种简单的巯基-二硫键交换策略来制备 DCC 角蛋白水凝胶。当还原剂提取的角蛋白溶液的 pH 值调节至 9.5-10.0 时，角蛋白水凝胶表现出可注射性、自修复、自适应、生物相容性和氧化还原响应能力。提取的 II 型中性/碱性角蛋白在赋予角蛋白水凝胶可逆性方面起着关键作用，因为角蛋白可以在碱性条件下通过巯基氧化和二硫键交换反应形成动态共价键。该策略为避免额外引入化学交联剂形成 DCC 角蛋白水凝胶提供了启示。
