Surface charge engineering shields extracellular vesicles from plasma protein corona to enable systemic extrahepatic targeting

fate of nanomedicines, yet its composition and impact on extracellular vesicles (EVs) remain poorly defined. Using a biomimetic circulation system, we characterized PC formation and modulation on two clinically relevant EV types: mesenchymal stromal cell-derived EVs (MSC-EVs) and HEK293F-derived EVs (293F-EVs). Under dynamic flow, both EV types acquired stable coronas, resulting in increased particle size and decreased surface charge. Proteomic profiling revealed a shared corona signature enriched in immunoglobulins, complements, and other plasma components. Functionally, PC formation enhanced macrophage uptake and triggered inflammatory activation, primarily via interactions between corona-bound immunoglobulins or complement C3 and their respective receptors. To disrupt this process, we developed a charge-shielding strategy using positively charged chitosan oligosaccharide (COS) to inhibit PC assembly. COS coating effectively neutralized EV surface charge and reduced opsonin adsorption and non-specific macrophage clearance, thereby reshaping EV biodistribution-limiting hepatic sequestration and enhancing delivery to extrahepatic organs. In a murine sepsis model, COS-modified MSC-EVs further improved renal and pulmonary outcomes and markedly increased survival. Collectively, these findings elucidate the molecular architecture and immunological impact of the EV-associated plasma PC and introduce a promising anti-corona strategy for engineering stealthier and more effective EV-based nanotherapeutics.