Separation of platelet extracellular vesicles from lipoproteins by monolithic anion-exchange chromatography

High production yield, purity, and quality are essential prerequisites for the development of biomedical extracellular vesicle (EV) products. Platelet-derived EVs (pEV) represent a promising source material for therapeutic applications. However, their isolation from blood products is challenging due to the overwhelming presence of lipoproteins, which are biophysically similar to EVs. In recent years, the demand for scalable EV isolation methods has prompted investigation into anion exchange chromatography-based approaches. While anion exchange provides an alternative, charge-based method for removing lipoprotein contaminants, a loss of EVs is experienced due to non-specific binding to the column. In this study, we evaluated different monolithic anion-exchange columns and optimized conditions to maximize the pEV yield while effectively removing lipoprotein contaminants. Four monolithic anion exchange columns-CIMmultus QA, CIMmultus DEAE, ProSwift SAX-1S, and ProSwift WAX-1S-were assessed for their purification performance. All columns achieved a pEV recovery rate of 30-70 % and a specific particle:protein ratio of 1.5-5.4 × 10¹¹ particles/A_280. The CIMmultus QA column demonstrated superior lipoprotein removal and was selected for further protocol optimization. This included the use of alternative counter-ions for more effective elution and buffer additives known to reduce non-specific interactions. Minor improvements in pEV yield were observed with the inclusion of urea or Tween 20. These findings support the development of a scalable production platform for blood-derived EVs, where effective separation from lipoproteins is critical. Further optimization of chromatographic conditions may enable selective isolation of biophysically distinct EV subpopulations, beyond conventional size- or affinity-based methods.