Ion osmolarity-driven sequential concentration-enrichment for the scale-up isolation of extracellular vesicles.

Extracellular vesicles (EVs) carry a variety of bioactive molecules and are becoming a promising alternative to cell therapy. Scale-up EV isolation is necessary for their functional studies and biological applications, while the traditional methods are challenged by low throughput, low yield, and potential damage. Herein, we developed an ion osmolarity-driven sequential concentration-enrichment strategy (IOSCE) for the EV isolation. IOSCE is composed of a novel superabsorbent polymers (SAPs) for EV concentration and a charged polymer for EV enrichment. Based on the driving force of ionic osmotic pressure, IOSCE can isolate EVs on a large scale from cell culture medium. The saturated water absorption capacity of IOSCE is 13.62 times higher than that of commercial SAPs. Compared with the ultracentrifugation method, IOSCE exhibited a 2.64 times higher yield (6.33 × 10⁸ particles/mL). Moreover, the mesenchymal stem cell-derived EVs isolated using IOSCE demonstrate strong biological activity and can reduce neuroinflammation by affecting RNA metabolism and translation processes. IOSCE provides a cost-effective, high-throughput, and low-damage method for the scale up EV isolation, which is promising for disease diagnosis and treatment.