Enzymatically gellable chitosan inks with enhanced printability by chitosan nanofibers for 3D printing of wound dressings

Chitosan-based hydrogels have received considerable attention as wound dressing materials. The utility of these materials can be further enhanced in combination with three-dimensional (3D) printing for the fabrication of dressings tailored to the specific needs of individual wounds. Here, we investigated the fabrication of wound dressings from hydrogel precursor inks containing phenolated chitosan (chitosan-Ph) and chitosan nanofibers (chitosan-NF) via 3D printing with horseradish peroxidase (HRP)-mediated hydrogelation. By adjusting the content of chitosan-Ph and chitosan-NFs, the ink viscosity, gelation time, and hydrogel stiffness could be controlled. The composite hydrogel exhibited antibacterial properties and cytocompatibility. In particular, hydrogels with 2% (w/w) chitosan-Ph and 1% (w/w) chitosan-NFs demonstrated superior design fidelity and promising wound healing properties compared to commercial dressings. These hydrogels promoted re-epithelialization, granulation tissue formation and extracellular matrix organization without exacerbating inflammation or foreign body reaction. These results underscore the efficacy of incorporating chitosan-NF into chitosan-Ph inks to produce patient-specific wound dressings by extrusion 3D printing, which represents a significant advancement in personalized wound care.