Fang Tao, Zhu Jingxin, Xu Shuai, Jia Lan, Ma Yanlong
College of Materials Science and Engineering, Taiyuan University of Technology Taiyuan 030024 China
RSC Adv. 2022 Apr 13;12(18):11574-11582. doi: 10.1039/d2ra00954d. eCollection 2022 Apr 7.
Regenerated silk fibroin (RSF)-based hydrogels are promising biomedical materials due to their biocompatibility and biodegradability. However, the weak mechanical properties and lack of functionality limit their practical applications. Here, we developed a tough and conductive RSF-based double network (DN) gel, consisting of a sonication-induced β-sheet physically crosslinked RSF/S gel as the first network and a hydrophobically associated polyacrylamide/stearyl methacrylate (PAAm/C18) gel as the second network. In particular, the cross-linking points of the second network were micelles formed by emulsifying the hydrophobic monomer (C18M) with a natural SF- capryl glucoside co-surfactant. The reversible dynamic bonds in the DN provided good self-healing ability and an effective dissipative energy mechanism for the DN hydrogel, while the addition of calcium ions improved the self-healing ability and electrical conductivity of the hydrogel. Under optimal conditions, the RSF/S-PAAm/C18 DN gels exhibited large extensibility (1400%), high tensile strength (0.3 MPa), satisfactory self-healing capability (90%) and electrical conductivity (0.12 S·m). The full physically interacted DN hydrogels are expected to be applied in various fields such as tissue engineering, biosensors and artificial electronic skin.
基于再生丝素蛋白（RSF）的水凝胶因其生物相容性和生物降解性而成为很有前景的生物医学材料。然而，其较弱的力学性能和缺乏功能性限制了它们的实际应用。在此，我们开发了一种坚韧且导电的基于RSF的双网络（DN）凝胶，它由作为第一网络的超声诱导β-折叠物理交联的RSF/S凝胶和作为第二网络的疏水缔合聚丙烯酰胺/甲基丙烯酸十八酯（PAAm/C18）凝胶组成。特别地，第二网络的交联点是通过用天然丝素蛋白-辛酰基葡糖苷共表面活性剂乳化疏水单体（C18M）形成的胶束。DN中的可逆动态键为DN水凝胶提供了良好的自愈能力和有效的能量耗散机制，而钙离子的加入提高了水凝胶的自愈能力和电导率。在最佳条件下，RSF/S-PAAm/C18 DN凝胶表现出大的延展性（1400%）、高拉伸强度（0.3 MPa）、令人满意的自愈能力（90%）和电导率（0.12 S·m）。完全物理相互作用的DN水凝胶有望应用于组织工程、生物传感器和人工电子皮肤等各个领域。
