Research advances in brain-targeted nanoscale drug delivery system

The blood-brain barrier (BBB) exerts its central nervous system (CNS) protective function as it hinders the delivery of diagnostic and therapeutic agents to the brain. With the development of nanotechnology during the last thirty years, the nanocarriers for delivering drugs make it possible to transport drugs across the BBB. The brain-targeted drug delivery system usually consists of two parts: nanocarriers and brain-targeted strategies. In this review, several kinds of nanocarriers are introduced for brain-targeted drug delivery. We focus on several possible strategies for brain-targeting and comment on their advantages and disadvantages in application.