EVs are being recognized as vectors for drug delivery. In particular, EV loading with targeting and therapeutic agents brings along an interesting opportunity to translate EVs into a biomimetic selective delivery system. Indeed, EVs constitute a physiological carrier being potentially less immunogenic than artificial delivery vehicles. The inventors now developed a novel method to control the loading of a cargo into EVs on demand. These EVs are equipped, if necessary, with non-viral fusogen, therefore enhancing EV-cargo delivery into acceptor cells. To acutely measure this process, they follow the fate of a luciferase-tagged cargo. Cargo loading was enabled through a drug-reversible inducible dimerization system. Briefly, donor cells were transfected with plasmids encoding for FKBP-tagged CD63, a classical membrane EV marker, and FRB-Nanoluciferase (NLuc) that is normally cytosolic. Upon addition of the dimerizing drug, FRB-Nluc interacts with FKBP-CD63 and is recruited into secreted EVs. This is accompanied by an enhanced delivery into acceptor cells. This phenomenon can be further enhanced when EVs are equipped with syncitin1, a mammalian fusogenic protein that trigger fusion between EV membrane and the plasma membrane of acceptor cells. Using this novel process, the inventors further demonstrated that the catalytic domain of the Diphteria toxin (DTA), that is responsible for protein synthesis inhibition and ultimately cell death, can be delivered to acceptor cells via functionalized EVs. This led to protein synthesis inhibition and death of acceptor cells. This novel method and the derived applications promise to open new doors in precision care medicine, especially when EVs will be equipped with antibodies raised against cell specific antigens.