Insights into cellulose nanocrystals-based bioinks for 3D bioprinting in regenerative medicine and tissue...

The manufacturing of biological tissue constructs by 3D bioprinting replicates the physiological characteristics of native tissue. This technology facilitates innovative research directions in biomaterials and biomedical sciences, revolutionizing both fundamental understanding and practical applications. Bioink development has expanded rapidly in the last decade for 3D bioprinting. In tissue engineering, bioink development remains a bottleneck. Nanocrystalline celluloses are a promising source of sustainable nanomaterials for bioink formulations in 3D bioprinting, owing to their structural resemblance to extracellular matrixes and excellent biocompatibility, which support essential cellular functions. Their versatile features, unique mechanical properties, and rich chemistry make cellulose nanocrystals an attractive option for bioink applications. However, their detailed properties have not been extensively studied in the emerging 3D bioprinting field, and cellulose-based bioink has received relatively little attention compared to other contemporary bioinks. This review paper discusses the properties of cellulose nanocrystals to unlock their biofabrication potential. Cellulose nanocrystals are suitable 3D printing bioink materials because of their low density, high strength, Young's modulus, and sustainability. Surface charge affects the rheology and viscosity of cellulose nanocrystal suspensions. These qualities significantly improve the biological and physicochemical properties of cellulose nanocrystal ink. This narrative review discusses how cellulose nanocrystals-based bioinks can be used to regulate bio-ink fidelity during 3D bioprinting.