Nowadays, nobody (I hope) believes anymore in the magic bullet, i.e. the molecule able to help DNA cross all barriers. Vectors of the future will be made much like viruses, of multifunctional supramolecular systems that self-assemble around DNA. Programmed intracellular disassembly may well be part of
a successful story too. Each component of the vector is assigned a function. As exemplified above, some functions may just be obtained by mimicking viruses, such as integrin-mediated cell entry, or NLS directed entry into the nucleus. Some other solutions, such as monomolecular genome condensation via detergent dimerization, or endosome release by the proton sponge effect, have obviously not been exploited by the natural cell invaders. The outcome of increased complexity of the vectors on their development as gene medicines [50] is difficult to evaluate at this stage. In any case, the pieces of the puzzle still have to be assembled prior to resembling an ‘artificial virus’ [51]: the quest of the Graal for the next decade?