Microbubble-enhanced Focused Ultrasound-induced Blood–brain Barrier Opening for Local and Transient Drug Delivery in Central Nervous System Disease

The blood–brain barrier is a specialized protective structure in the central nervous system, which is critical for maintaining brain homeostasis and low permeability to control the passage of molecules from the circulation into the brain parenchyma and the efflux from the brain. However, the blood–brain barrier also hinders the transportation of therapeutic agents and contrast agents from the blood into brain tissue, lowering treatment efficiency. Recently, focused ultrasound sonication with microbubbles has been proved to transiently open the blood–brain barrier, allowing the penetration of administered agents or drugs into the brain. In this article, we review the current state of this drug delivery technique, its application in preclinical brain disease models, and treatment planning for this novel technique.