The intra-brain distribution of brain targeting delivery systems

Abstract Brain is the most complex organ in human body. The prevalence of CNS diseases and their associated secondary diseases has become the growing threat and huge disease burden to the global society. Most medications in treating brain diseases have failed to yield significant therapeutic outcomes because of the impermeable membrane barriers lying between the brain and the circulation system, the blood-brain barrier (BBB). As a result, the brain drug delivery imposes a global challenge in the development of more effective CNS medications. In this chapter, the anatomic features, brain circulation, as well as the brain microenvironment, are described in details. Apart from the BBB, other obstacles involved in brain drug delivery also attribute to the diffusion problems and cell selectivity. To address these issues, a number of nanomaterial-based techniques, including cell-penetrating peptide-based permeation-enhancing strategy and receptor-mediated targeting delivery, which have been widely explored to improving the delivery efficiency of brain drugs, are discussed in the second part of this chapter.