Design and development of gellan gum–derived photocrosslinkable hydrogel-based biomaterial inks for extrusion-based 3D printing

Three-dimensional (3D) printing enables the fabrication of hydrogel constructs with precise architecture, yet developing photocurable hydrogel biomaterial ink that combine printability, structural stability, and biofunctionality remains a challenge. Here, we present a gallol-functionalized gellan gum methacrylate (GGMA-GA) hydrogel as a robust photocrosslinkable biomaterial ink for extrusion-based 3D bioprinting. A dual-crosslinking strategy was employed in which mild ionic pre-crosslinking enhances shear-thinning and print fidelity, followed by photocrosslinking of methacrylate groups to reinforce mechanical stability post-printing. Incorporation of gallol moieties provides antioxidant activity and tissue adhesion, mitigating oxidative stress and promoting construct integration. We systematically evaluated rheological and swelling properties, printability, and cytocompatibility, demonstrating that GGMA-GA hydrogels maintain structural fidelity while supporting cell viability. The combination of low swelling degree, enhanced functionality, and precise printability positions GGMA-GA as a versatile photocurable hydrogel platform for extrusion-based 3D fabrication, with potential for long-term and in situ biomedical applications.