2020 Volume 69 Issue 12 Pages 731-735
An exosome is one of the extracellular vesicles containing specific proteins, nucleic acids, and sugars. A number of recent reports have shown that exosomes contribute to transporting functions among cells. To facilitate the exosome studies, we focus on the specific separation of exosomes by the recognition of sugar chains on the surface of exosomes. As a typical separation based on sugar chains, lectin affinity chromatography (LAC) which is currently used to purify glycoproteins, is usually employed. However, the pore size of the LAC packing material is fairly small, so that the use of such materials is not suitable for the separation of exosomes having over 100 nm in diameter. To achieve an effective exosome separation, a spongy monolith (SPM), which consists of poly(ethylene-co-glycidyl methacrylate) (PEGM), is expected as a separation medium for LAC. In this study, we prepared two kinds of LAC columns made of the SPMs, immobilized with sambucus sieboldiana agglutinin (SSA) or concanavalin A (ConA). As results, glycoproteins (transferrin and glucose oxidase) were effectively interacted with their respective lectins. Along with glycoproteins, mannose-integrated liposomes were also interacted and rapidly desorbed using the ConA-immobilized SPM (ConA-SPM). Finally, the ConA-SPM was employed for the separations of exosomes, and then the exosomes after passing through the ConA-SPM represented different glycan profiles against the original sample. These results suggest that the lectin-immobilized SPMs will be useful for the separation of exosomes based on the recognition of the surface sugar chains.
