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 ± 1.01e10 particles/μg,
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.