For most of us, the brain's blood-barrier is a blessing; the mechanism keeps viruses away from the brain while letting oxygen and other beneficial nutrients through. But to scientists trying to figure out treatments and cures for neurologic diseases like Parkinson's or Alzheimer's, that blood-brain barrier is a pain, locking out therapeutic genes and molecules.
So, the story of drug delivery development these days seems to be increasingly about breaking through that final frontier--the blood-brain barrier.
Scientists from the University of Texas MD Anderson Cancer Center managed to sneak peptides past the brain's protective barrier by creating a particle that's a kind of master of disguise. It impersonates iron, and then hops onboard the body's iron transport system for a free ride into the brain. Along the way, the researchers say, the disguised particle could be used to deliver imaging agents or treatments. Article
At Chang Gung University in Taiwan, researchers have a nanoscale way of getting through. The researchers, led by Kuo-Chen Wei, injected nanosize magnetic beads coated with a chemotherapy drug, into the rats' tails. Ultrasound opens up a small part of the blood-brain barrier and they use a magnetic field to lure the particles to an exact location in the brain. Article
There are still questions about toxicity of nanoparticles - especially in an area as sensitive as the brain. But there is no doubt that as these questions are cleared up, it is in the brain that, perhaps, nanotech will see its greatest triumph. That is truly where size does matter.