Design of silk fibroin-based supramolecular hydrogels through host-guest interactions: Influence of the crosslinking type

Due to their pivotal role in non-textile utilization of silk, silk fibroin (SF)-based hydrogels continue to receive a lot of attention, in order to discover new crosslinking methods. SF may form stable inclusion complexes with β-cyclodextrins (β−CD) driven by host-guest interactions between β−CD and amino acid side chains (such as tyrosine, tryptophan, phenylalanine and histidine). This favorable feature makes supramolecular assembly a promising crosslinking method for construction of SF-based hydrogels. However, different β−CD conjugation methods lead to variations in hydrogel properties; influence of the crosslinking types and the related underlying mechanisms remain to be elucidated. In this study, new types of SF-based hydrogels were designed based on host-guest interactions between β−CD and the amino acids, showing that the hydrogel properties could be adjusted by employing either different solvation methods for regenerating SF or diverse conjugation methods for β−CD. This study not only provides a new generation of SF-based hydrogels, but also greatly expands the supramolecular assembly strategy for design of protein-based hydrogels.