Abstract Charged polymer interactions govern biological and technological processes by altering the structure and dynamics of surrounding water. Studying these interactions across a broad concentration range is challenging, particularly at submicromolar levels where traditional methods lack sensitivity or molecular resolution. Here, we investigate interactions between hyaluronan (HA), a biologically and technologically relevant polymer, and model oligopeptides—nonaarginine, nonalysine, and nonaglycine. By combining angle-resolved second harmonic scattering (AR-SHS), dynamic light scattering, nuclear magnetic resonance, and all-atom molecular dynamics simulations, we resolve the molecular-scale mechanisms and structure of HA–peptide interactions. Our findings reveal selective, multivalent binding between HA and cationic peptides, inducing solvent and solute restructuring and nanoscale clustering. Simulations provide atomic-level insight, elucidating the transient nature of the interactions and highlighting the distinctive behavior of arginine-rich peptides. Our approach, integrating AR-SHS with simulations and routine techniques, offers molecular insights into polymer mixtures and a foundation for future studies of dynamic supramolecular systems in soft materials.
Riopedre-Fernández et al. (2026) studied this question.