Surface Nanosieving Polyether Sulfone Particles with Graphene Oxide Encapsulation for the Negative Isolation toward Extracellular Vesicles

Extracellular vesicles (EVs) contain specific biomarkers for disease diagnosis. Current EV isolation methods are hampered in important biological applications due to their low recovery and purity. Herein, we first present a novel EV negative isolation strategy based on surface nanosieving polyether sulfone particles with graphene oxide encapsulation (SNAPs) by which the coexisting proteins are irreversibly adsorbed by graphene oxide (GO) inside the particles, while EVs with large sizes are excluded from the outside due to the well-defined surface pore sizes (10-40 nm). By this method, the purity of the isolated EVs from urine could be achieved 4.91 +/- 1.01e(10) particles/mu g, 40.9-234 times higher than those obtained by the ultracentrifugation (UC), size-exclusion chromatography (SEC), and PEG-based precipitation. In addition, recovery ranging from 90.4 to 93.8% could be obtained with excellent reproducibility (RSD < 6%). This was 1.8-4.3 times higher than those obtained via SEC and UC, comparable to that obtained by PEG-based precipitation. Taking advantage of this strategy, we further isolated urinary EVs from IgA nephropathy (IgAN) patients and healthy donors for comparative proteome analysis, by which significantly regulated EV proteins were found to distinguish IgAN patients from healthy donors. All of the results indicated that our strategy would provide a new avenue for highly efficient EV isolation to enable many important clinical applications.