Concepts, technologies, and practices for drug delivery past the blood-brain barrier to the central nervous system.

While neurodegenerative diseases and cancers are on the rise, treatments for diseases of the central nervous system (CNS) remain limited. The blood brain barrier (BBB) poses the greatest challenge to CNS drug delivery and has therefore been a primary focus in the development of novel CNS drug delivery techniques. Limitations set by the BBB include molecule size, polarity, substrate specificity, and active efflux mechanisms. Strategies to overcome these challenges include drug delivery systems in conjunction with other chemical and physical targeting or BBB disruption mechanisms. This review outlines and describes the recent strategies employed to overcome challenges of drug delivery to the CNS while providing insight into promising techniques for future work.