Single-Helical Dopamine-g-Curdlan Hydrogels Showing High Adhesiveness and Injectability.

Abstract

Polysaccharide-based hydrogels with strong tissue adhesion, injectability, and self-healing capability are highly desirable for wound management, yet their performance is often limited by rigid polymer conformations and insufficient interfacial interactions. Here, we report a mussel-inspired, dopamine-grafted curdlan hydrogel (Cur-DA) featuring a predominantly single-helical β-glucan architecture. Cur-DA hydrogels were synthesized under alkaline conditions using ethylene glycol diglycidyl ether (EGDE) as a linker, thereby facilitating regioselective dopamine grafting at the C6 position of curdlan. Spectroscopic analyses (UV-Vis, FTIR, solid-state 13C NMR, XRD, and circular dichroism), together with XPS characterization, confirmed successful dopamine incorporation and a conformational transition from native triple helices to more flexible single helices. With this single-helical architecture and catechol functionalization, Cur-DA formed a nanofibrous, porous network with high water content (>90%), increased swelling capacity, and excellent mechanical compliance. Owing to catechol-mediated interfacial interactions and the mobility of single-helical chains, which likely serve as dynamic "sticky ends," Cur-DA hydrogels exhibited robust tissue adhesion (up to 10.21 kPa), self-healing, and outstanding injectability. In vitro assays indicated excellent hemocompatibility and cytocompatibility. In a murine full-thickness skin wound model, an optimized formulation (Cur-DA3) accelerated wound closure, promoted re-epithelialization, and enhanced collagen deposition without inducing systemic toxicity. This work establishes a conformation-engineering strategy for β-glucan hydrogels and highlights Cur-DA as a promising injectable, adhesive wound dressing.