Direct Observation of Intermediate Water on Blood-Compatible Polymer Surfaces

Researchers from Kyoto University and Terumo Corporation have directly observed "intermediate water" on the surface of the blood-compatible polymer PMEA using liquid-phase frequency modulation atomic force microscopy, supporting the hypothesis that this hydration layer suppresses protein adsorption. The study, led by Associate Professor Kei Kobayashi and doctoral student Yilin Wang, compared PMEA with the less blood-compatible polymer PBMA, finding that PBMA surfaces exhibited hydrophobic hydration structures and were relatively hard, potentially serving as scaffolds for protein adsorption. Published in Nano Letters on August 24, 2026, the findings could enable AI-driven prediction and inverse design of blood-compatible materials by combining nanoscale measurements with computational simulations.