Dynamic biological interfaces functionalized fructose-responsive immunomagnetic beads for high-efficient and high-purity exosome enrichment

Enrichment of exosomes with high structural and functional integrity is a critically important step before downstream applications in biological and clinical domains. In this work, dynamic biological interfaces functionalized fructose-responsive immunomagnetic beads (Fr-IMBs) were fabricated by incorporating the dynamic biological interfaces composed of dopamine and 4-carboxyphenylboronic acid with immunomagnetic beads. These fabricated Fr-IMBs were successfully applied to capture the MCF-7 exosomes with a high capture efficacy of 91.0%. After incubation with fructose, the molecular structure of the dopamine-boronic acid complexation can be rearranged and the antibody (anti-CD63) bound exosomes were released competitively, with a yield greater than 79.8%. Those exosomes that underwent both immunomagnetic separation and fructose triggered release remained their good bioactivity to promote MCF-7 cell migration. Better yet, exosomes enriched by Fr-IMBs possessed higher purity and better preservation of tumor-related molecular information of the exosomal proteins than those obtained through the ultracentrifugation approach, as proved by the comparative proteomics. These proposed sugar-responsive immunomagnetic beads may serve as biofriendly candidates in enriching useful biomarkers (e.g., cells, nucleic acids, proteins, etc.) efficiently from complex biological samples with high purity.