Protein corona modulates extracellular-vesicle recognition at glycan-based nanobiointerfaces.

Precise surface engineering is essential for robust characterization of extracellular vesicles and their interactions with biologically relevant interfaces. In this study, Au substrates were modified with C6 self-assembled monolayers (SAMs) bearing different terminal groups after multiple cleaning protocols to optimize monolayer compactness and interfacial quality. Surface area and functionality were further enhanced by gold nanoparticle (AuNP) deposition and secondary SAM formation, enabling layer-by-layer assembly of glycan-based polysaccharide nanostructures. Interface fabrication and growth were monitored by electrochemical methods and atomic force microscopy (AFM). Extracellular vesicles (EVs) from MDA-MB-231 breast cancer cells and benign RWPE-1 (control) cells were affinity isolated using magnetic microparticles, chromatographically preconcentrated, and subjected to protein-corona removal prior to analysis. The impact of the protein corona on antibody-mediated recognition was evaluated by ELISA and revealed markedly improved accessibility of EV surface markers following corona removal. Interactions of EVs with extracellular-matrix-mimicking glycan interfaces were investigated using surface plasmon resonance (SPR). Sensorgrams were analyzed using a physics-informed neural-network-assisted model to extract dissociation constants while reducing the influence of bulk refractive-index contributions typical of vesicle samples. The developed nanobiointerfaces enabled sensitive characterization of EV binding behavior and revealed distinct interaction phenotypes of malignant-derived and non-malignant-derived EVs toward glycan-based surfaces. These findings demonstrate that protein-corona composition and glycan-mediated interactions significantly influence EV recognition and highlight the potential of glycan-based nanobiointerfaces as tools for studying extracellular-vesicle biology, which may contribute to future liquid-biopsy development.