Design\nof Self-Healing and Electrically Conductive Silk Fibroin-Based Hydrogels

Abstract

Self-healing\nand electrically conductive silk fibroin (SF)-based hydrogels were\ndeveloped based on the dynamic assembly/disassembly nature of supramolecular\ncomplexes and the conductive nature of polypyrrole (PPy). The self-healing\nproperties of the hydrogels were achieved through host–guest\ninteractions between β-cyclodextrin and amino acid side chains\n(tyrosine, tryptophan, phenylalanine, and histidine) on SF. PPy deposition\nwas achieved via in situ polymerization of pyrrole using ammonium\npersulfate as an oxidant and laccase as a catalyst. The PPy-coated\nhydrogels behaved as an elastomer and displayed excellent electrical\nproperties, with adjustable electrical conductivities ranging from\n0.8 ± 0.2 to (1.0 ± 0.3) × 10^–3 S·cm^–1. Furthermore, possibility of potential utilization\nof the hydrogels in electrochemistry applications as flexible yet\nself-healable electrode materials was explored. This study not only\nshows great potential in expanding the role of silk-based devices\nfor various applications but also provides a useful approach for designing\nmultifunctional self-healing protein-based hydrogels.