Mechanical Extrusion of the Plasma Membrane to Generate Ectosome-Mimetic Nanovesicles for Lung Targeting.

Extracellular vehicles (EVs) are naturally occurring nanocarriers that participate in the transportation of biologics between cells. Despite their potential in drug delivery, their optimal use in therapy remains a challenge, which comes from the difficulty in preparation scale-up and cargo loading efficiency. As a membrane-enclosed nanoscale system, EVs are reluctant to be transfected with cargos and purified by conventional methods. In the present study, we proposed an EV-mimetic nanovesicle system to overcome the challenges. Using the easy-culture mammalian cells as raw materials, we isolated the plasma membrane sheets and vesiculated them into membrane-enclosed nanovesicles as an EV mimic by the mechanical extrusion through porous membranes. In order to controllably load the cargos in the lumen of vesicles, the endogenous actin filament was chosen as an anchor to capture the cargos (fused with an anti-actin nanobody) in the inner leaflet of plasma membrane sheets and vesiculated inside after extrusion. By loading the bioluminescent tracer nano-luciferase (Nluc) and tracking biodistribution in mice, we unclosed the lung-tropic nature of these nanovesicles. Furthermore, we demonstrated that nanovesicles can be genetically engineered with chimeric antigen receptors to achieve the active targeting of lung cancer cells. In conclusion, our study indicated that plasma membrane extrusion might be an applicable approach to generate EV mimics for drug delivery, especially to the lung tissue.