The present work describes the synthesis, structural and mechanical characterisation of soft polymeric materials used for biomedical purposes. This thesis is separated in two parts: the first one pays special attention to natural polymeric hydrogels for Tissue Engineering (TE) described in chapter 3 and chapter 4 describes the synthesis of magnetically responsive nanocomposite hydrogels for TE. In this first part, I mainly focus on the mechanical characterisation of the synthesised materials. I use AFM microindentations to characterise them locally and oscillatory shear rheometry to characterise the bulk responses of the material, obtaining the reduced Young's modulus (E*), the storage G' and the loss G'' modulus respectively. Furthermore, in chapter 3, the assessment of the stability of microbeads made of alginate for modular TE is described, followed by a novel magneto-mechanical coupling observed for the first time in chitosan hydrogels. In the 4th chapter, I characterise the mechanical response of a chitosan-Fe₃O₄ nanocomposite with an enhanced magneto-mechanical coupling. The second part of this work (chapter 5) describes a simple synthesis of polymeric micro-ellipsoidal particles for torque generation assays in biomedicine. I characterise the rotation of these particles in comparison to commercially available spherical microparticles and their enhanced ability to follow low magnetic rotating fields.