Strategies for drug delivery to the brain

Many potential CNS active agents, including peptides, proteins, antibodies, and gene medicines, do not readily enter brain from blood, owing to poor permeability through the blood-brain barrier (BBB). The successful delivery of these agents through the BBB in vivo is closely linked to knowledge of pharmacokinetics and transport mechanism at the brain capillary endothelium. In this review, we discuss brain delivery strategies of peptides and proteins from view points of pharmacokinetics and BBB transport mechanism. In addition, this review summarizes recent information regarding the transport system of peptides and proteins. Furthermore, some novel technologies for BBB delivery strategies are introduced in the last part of the review.