ABSTRACT

This chapter reviews the various parameters that should be considered when designing nano-drug-delivery systems (DDSs) for brain delivery and the present achievements in the field. The small dose needed for therapeutic efficiency would easily fit the loading capacity of nano-DDSs and avoid the administration of large amount of potentially toxic nano-DDS excipients. In the case of larger nano-DDSs such as liposomes, the uptake by infiltrating macrophages is probably the mechanism for their increased distribution into inflammatory brain tissues. Only receptor-mediated transcytosis may be used for transcytotic delivery of nano-DDSs through the blood–brain barrier (BBB). A nanoparticle-induced nonspecific BBB permeabilization, resulting from the synergistic effect of nanoparticle toxicity and high polysorbate 80 concentrations, was proposed as an alternative mechanism to the brain translocation of nanoparticles across the BBB. A scientific consensus locates the BBB at the endothelia of brain capillaries which are in close relationship with the surrounding pericytes, actrocytes, neurons, and glial cells.