Advances in nanocarriers enabled brain targeted drug delivery across blood brain barrier.

The blood brain barrier (BBB) offers protection to the central nervous system (CNS) by maintaining homeostasis. Besides restricting the entry of harmful xenobiotics and endogenous molecules to CNS, BBB also limits the entry of therapeutic agents. Nanotechnology offers the possibility to deliver small molecules/drugs against CNS disorders across BBB. Recently, due to excellent biocompatibility, functional versatility and unique surface electrostatics properties nanodiamonds are also being explored for their drug delivery potential against BBB. Although, studies has been done to understand the mechanisms involved in drug delivery across BBB, but still, progress in the development of any functional drug delivery systems across BBB is in juvenile stages. For this purpose, the strategic developments of more potent drug delivery systems to CNS via endocytic pathways appears to be the most promising approach. Endocytic pathways are essential for communication and transport of nutrients across BBB in endothelial cells. Moreover, modifications of the nanotherapeutic agents with specific brain capillary endothelial cells targeting molecules or ligands have recently shown impressive results of successful delivery of drugs to the brain via receptor-mediated transcytosis. The current review provides a comprehensive insight in the advancements made in nanocarriers-based successful drug delivery to the CNS and their availability in clinics.