Role of cellulose and its derivatives for 3D printing of bone tissue scaffolds.

3D printing has become central to bone tissue engineering, yet many printable polymers lack the mechanical strength, hydrophilicity, and bioactivity needed for effective bone regeneration. Cellulose and its derivatives have emerged as versatile additives that address these limitations across multiple scaffold types. This review highlights recent advances in 3D printed scaffolds incorporating cellulose nanocrystals (CNC), microcrystals (MCC), nanofibrils (CNF), bacterial cellulose (BC), and chemically modified cellulose derivatives including carboxymethyl cellulose (CMC), methyl cellulose (MC), diethylaminoethyl-modified cellulose (DEAE) and cellulose acetate (CA). In hydrogels, CNF and BC provide shear-thinning behavior and mechanical strength, while in polymer-ceramic hybrids, CNC improves stiffness. CA, owing to its thermoplastic processability and tunable hydrophobicity, enables high-resolution extrusion and melt-based printing while serving as a mechanically stable backbone that can be further biofunctionalized through surface modification. CMC, MC and DEAE cellulose are key printing enablers when blended with polymers such as gelatin or HAp. This review also shows that further modification of cellulose seems to enhance its potential for future clinical translation. Together, these findings demonstrate that cellulose is a key design element that transforms mechanically weak or biologically inert inks into robust, osteoconductive scaffolds. The review concludes with emerging trends and remaining opportunities for cellulose-based bioinks in bone regeneration.