Preparation and characterization of mussel-inspired dual-crosslinked hydrogels based on hydroxypropyl chitosan

Marine mussels can adhere to various surfaces in a liquid environment by utilizing pedicle filaments, with the adhesive properties primarily attributed to the structure of catechol, the main component of the filament. To overcome the challenges associated with the complex preparation process, high cost, and potential biological rejection of naturally extracted or recombinantly expressed mussel proteins, researchers drew inspiration from mussels and utilized an oxidative crosslinking approach to prepare adhesive hydrogel materials. However, the hydrogels prepared using this method exhibited inferior mechanical properties and low viscosity. To address these limitations, in this study, a kind of mussel-inspired dual-crosslinked hydrogel was prepared by dual cross-linking with hydroxypropyl chitosan (HPCS) and hyaluronic acid (HA), based on catechol, an adhesion component in marine mussel pedicle filaments. Comparative analysis revealed that the mussel-inspired dual-crosslinked hydrogel exhibited significantly higher adhesion strength (up to 33.96 kPa) and improved mechanical properties (energy storage modulus ranging from 489 to 1032 Pa) compared to the mussel-inspired oxidatively cross-linked hydrogel. In addition, the mussel-inspired dual-crosslinked hydrogel demonstrated favorable swelling (up to 136.54 ± 0.22