Microfibrillated cellulose (MFC)-composite formulations for 3D bioprinting with excellent printability, mechanical strength, and biological functionality

Bioprinting enables precise control of cell distribution within complex 3D geometries to replicate the heterogeneity and hierarchically organized nature of native tissue. However, simultaneously meeting the multifaceted requirements of printability, mechanical robustness, and biological functionality remains a critical challenge for constructing efficient bioprinted scaffolds. We developed a bio-based strategy by integrating microfibrillated cellulose (MFC) into gelatin methacryloyl/sodium alginate (G/A) formulations to harmonize these requirements. The MFC-composited G/A formulation achieved excellent shear-thinning behavior (flow index of 0.22) and printing fidelity (printability index of 0.892), enabling precise deposition of cell-laden constructs with sustained cell viability over 21 days. Enhanced microscopic homogenization of ion-covalent entanglement (ICE) networks within G/A hydrogels was corroborated from the decreased pore size and concentrated pore size distribution in the presence of MFC. The prolonged biodegradation process of MFC ICE hydrogels matched well with the growth timeline of the encapsulated cells. Addition of MFC further increased ampicillin loading capacity in ICE hydrogels and enabled sustained release without compromising the antibacterial efficacy, highlighting the potential of this formulation for long-term treatment within damaged tissues. Our work demonstrates that MFC-composite G/A bioprinting systems can offer comprehensive advantages in performance, offering a scalable and sustainable approach to accomplish functional 3D-bioprinted therapeutics. • Bio-based strategy by integrating microfibrillated cellulose (MFC) into gelatin methacryloyl/sodium alginate (G/A) formulations to meet the requirements for bioprinting • Excellent shear-thinning behaviour (flow index of 0.22) and printing fidelity (printability index of 0.892) • Enhanced microscopic homogenization of ion-covalent entanglement (ICE) networks within G/A hydrogels • Prolonged biodegradation process of MFC ICE hydrogels match well with the growth timeline of the encapsulated cells