Electric Field Assisted Tangential Flow Filtration Device for Highly Effective Isolation of Bioactive Small Extracellular Vesicles from Cell Culture Medium.

Small extracellular vesicles (sEVs) are proven to hold great promise for diverse therapeutic and diagnostic applications. However, batch preparation of sEVs with high purity and bioactivity is a prerequisite for their clinical translations. Herein, we present an electric field assisted tangential flow filtration system (E-TFF), which integrates size-based filtration with electrophoretic migration-based separation to synergistically achieve the isolation of high-quality sEVs from cell culture medium. Compared with the gold-standard ultracentrifugation (UC) method, E-TFF not only improved the purity of sEVs by 1.4 times but also increased the yield of sEVs by 15.8 times. Additionally, the entire isolation process of E-TFF was completed within 1 h, about one-fourth of the time taken by UC. Furthermore, the biological activity of sEVs isolated by E-TFF was verified by co-incubation of sEVs derived from human umbilical cord mesenchymal stem cells (hUCMSCs) with HT22 mouse hippocampal neuronal cells exposed to amyloid-β (Aβ). The results demonstrated that the sEVs isolated by E-TFF exhibited a significant neuroprotective effect. Overall, the E-TFF platform provides a promising and robust strategy for batch preparation of high-quality sEVs, opening up a broad range of opportunities for cell-free therapy and precision medicine.