Engineering printable and mechanically robust hyaluronic acid biomaterial inks through cellulose material selection

Despite excellent biocompatibility, hyaluronic acid (HA) exhibits poor 3D printability, insufficient mechanical properties, and uncontrolled degradation in tissue engineering applications. This study developed HA-based biomaterial inks by integrating cellulose materials, including cellulose nanocrystals (CNC), carboxymethyl cellulose (CMC), and methylcellulose (MC), into a methacrylated hyaluronic acid matrix. The influence of cellulose material structure and concentration on the rheological characteristics, 3D printability, and temporal evolution of physical properties during degradation was systematically elucidated. Results demonstrated that CNC served as a nano-reinforcing phase to enhance the mechanical properties of hydrogels, while CMC and MC functioned as rheological modifiers to improve pre-crosslinking rheological behavior. The incorporation of cellulose materials at varying concentrations into the HA matrix proved to be an effective strategy for modulating the mechanical performance of hydrogels. Upon photo-crosslinking, the prepared biomaterial inks produced intact printed structures with high mechanical properties and stability. The HA/CNC hydrogels retained approximately 83% of initial strength by day 14, maintaining load-bearing capacity and structural integrity throughout degradation. This work elucidates the synergistic mechanisms by which cellulose materials regulate multi-scale properties of HA biomaterial inks, providing a theoretical foundation for developing high-fidelity, mechanically tunable, and degradation-controllable 3D-printed tissue engineering scaffolds.