Macromolecules which are able to form condensed phases in water have received attention due to their potential for a variety of applications. Thus, characterization of these systems on molecular level is a very important but challenging task. We investigated the dynamic properties of macromolecules including their mobility, hydration level and local density in the condensed phase by Electron Paramagnetic Resonance spectroscopy. In addition complementary studies on dynamic properties of the solvent surrounding the macromolecule were performed by Overhause Dynamics Nuclear Polarization NMR spectroscopy. Both techniques provide unique site-specific information of local molecular and water dynamics through site-directed spin labeling approach. Two systems were investigated: (1) A supramolecular synthetic polymer composed of benzene-1,3,5-tricarboxamide (BTA), which self-assembles into fibers in water. These have the ability to form hydrogels and also it is possible to functionalize the sidechains of the BTA molecules, making it a good candidate for biomedical applications like drug delivery systems. (2) Mussel foot proteins that have recently received increased attention in an effort to understand their mechanism of underwater adhesion, a task currently impossible with man-made glues. We characterized two mussel foot protein 3 variants (mfp3f and mfp3s) which form coacervates (liquid – liquid phase separation) in water under appropriate conditions. The results show that the coacervate formed by mfp3s is denser, more viscous, and potentially drier than the one formed by mfp3f. For both cases, this work is expected to advance the fundamental understanding of the role of water in influencing the molecular structures and aggregation in aqueous solution.