The present invention relates to modification of cellulose nanofibrils (CNF) with extracellular matrix components such as collagen, elastin, fibronectin or RGD sequences or growth factors such as TGFBeta using for example EDS-NHS conjugation method and preparation of bioinks for 3D Bioprinting of tissue models such as human skin or neural tissue. Cellulose nanofibrils provide excellent printing fidelity which is crucial for diffusion of oxygen and diffusion of nutrients into the 3D bioprinted constructs. The surface conjugated extracellular matrix components induce biological activity by providing adhesion sites or inducing differentiation process. 3D Bioprinted bioinks based on CNF bioinks showed great ability inducing adhesion of human fibroblasts and stimulating Collagen I production. Such bioinks are thus suitable for 3D Bioprinting of tissue models.
