Antimicrobial peptide drugs are increasingly attractive therapeutic agents as their roles in physiopathological
processes are being unraveled and because the development of recombinant DNA technology has made them economically
affordable in large amounts and high purity. However, due to lack of specificity regarding the target cells, difficulty
in attaining them, or reduced half-lives, most current administration methods require high doses. On the other hand, reduced
specificity of toxic drugs demands low concentrations to minimize undesirable side-effects, thus incurring the risk
of having sublethal amounts which favour the appearance of resistant microbial strains. In this scenario, targeted delivery
can fulfill the objective of achieving the intake of total quantities sufficiently low to be innocuous for the patient but that
locally are high enough to be lethal for the infectious agent. One of the major advances in recent years has been the size
reduction of drug carriers that have dimensions in the nanometer scale and thus are much smaller than —and capable of
being internalized by— many types of cells. Among the different types of potential antimicrobial peptide-encapsulating
structures reviewed here are liposomes, dendritic polymers, solid core nanoparticles, carbon nanotubes, and DNA cages.
These nanoparticulate systems can be functionalized with a plethora of biomolecules providing specificity of binding to
particular cell types or locations; as examples of these targeting elements we will present antibodies, DNA aptamers, cellpenetrating
peptides, and carbohydrates. Multifunctional Trojan horse-like nanovessels can be engineered by choosing the
adequate peptide content, encapsulating structure, and targeting moiety for each particular application.