The blood-brain barrier, the thorn in the side of medicine. It makes using drugs directed for the brain ineffective at best and unusable at worst. This barrier runs inside almost all vessels in the brain and protects it from elements circulating in the blood that may be toxic to the brain. This barrier means that currently 98% of therapeutic molecules are also unable to cross to the brain. However, researchers now say magnetic nanoparticles can open the blood-brain barrier and deliver molecules directly to the brain.
The blood-brain barrier helps that finicky brain of yours maintain the delicate environment that it needs to thrive. There’s just one problem: The barrier is so good at what it does, it won’t let medicines pass through. Like most things with the brain, we don’t know enough about it to control it for our benefit.