Mechanical Characterization and Bio-printability of Synthetic Fibrillar Hydrogels

This thesis describes the preparation and characterization of a novel synthetic nanofibrillar hydrogel composed of gelatin methacryloyl (GelMA) and aldehyde -modified cellulose nanocrystals (a -CNCs). This hydrogel recapitulates the fibrillar network present in the extracellular matrix (ECM), making it an ideal candidate for cell culture studies. By manipulating the degree of intrafibrillar crosslinking, a broad -range control over the hydrogel mechanical properties was established without a ltering its composition . This decoupling was used to demonstrate the sole impact of the hydrogel stiffness on the contraction and activation of lung fibroblasts. Furthermore, the dependency of the hydrogel mechanical properties on its composition and crosslinking was modelled by a machine-learning algorithm to propose hydrogel recipes with target stiffnesses. The hydrogel demonstrated good bio -printability on an extrusion -based 3D bioprinter and was thus incorporated as a cell culture medium into a bio-printed 3D in vitro model of melanoma skin cancer.