Mechanical\nExtrusion of the Plasma Membrane to Generate\nEctosome-Mimetic Nanovesicles for Lung Targeting

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