Hydrogels are used as scaffolds in Tissue Engineering and Regenerative Medicine (TERM) for different applications such as delivery vehicles for bioactive molecules, space filling agents and as three-dimensional structures hosting cells to stimulate the regeneration of the desired tissue. For this purpose, a key factor in designing biologically active scaffolds is to optimize their properties to the application they will serve for or the nature of the tissue to regenerate. With the recent advances to control the hydrogels porosity, shape, size and surface morphology, new opportunities have emerged to overcome various challenges in Tissue Engineering. Physically cross-linked hydrogels formed by small molecules called Low Molecular Weight Gelators (LMWG) form physical networks composed of selfassembled nanofibers mimicking the extra cellular matrix, making these hydrogels a great choice for TERM. In this work, a recently discovered bis-urea LMWG will be combined with different metallic ions to study their influence on chemical composition, hydrogels and fibres morphology, mechanical and biological properties. Moreover, chemically cross-linked hydrogels formed by 8-branched poly(ethylene) glycol (PEG) with different functional groups will be synthetized and characterized in terms of swelling ratio, chemical characterization and biological and mechanical properties to understand their gelation mechanisms and biocompatibility. In the future of this PhD thesis, these PEG-hydrogels will be combined with nanoparticles such as cellulose or starch nanoparticles to study their influence on the mechanical and biological properties.