bubbles with ultrasound - stroke drugs directly into the brain

So I wonder which would be better, nanoparticles or bubbles? Or is it the xenon gas?

bubbles with ultrasound  - stroke drugs directly into the brain

Now, stroke drugs directly into the brain (Thinkstock photos/Getty Images)
Scientists believe that bubbles could deliver a devastating blow to disease.
Injected into the blood, tiny bubbles of gas can ease the passage of vital stroke drugs into the brain, helping prevent damage to the grey matter.
Now, a group of researchers calling themselves ''the bubble community'' are studying how they could help fight disease.
They have shown that blasting bubbles with ultrasound makes them move back and forth, and, bizarrely, makes it easier for nearby cells to take up medicines.
"The theory is that the bubbles are stimulating the natural uptake mechanisms," the Daily Mail quoted Eleanor Stride, of University College London, as saying.
"Exactly which mechanisms, we're not sure."
Bubbles can even open up the blood-brain barrier, the protective blockade that regularly stops drugs from getting into the brain from the bloodstream.
Stride told New Scientist : "If you expose the blood-brain barrier to bubbles and ultrasound, you can temporarily and reversibly enhance its permeability, which is potentially interesting for a lot of brain treatments."
Examples include the treatment of stroke, in which an interruption of the blood supply to the brain causes cells to become damaged or die.
Researchers from the University of Cinncinnati in Ohio filled microbubbles with xenon - a gas known to protect brain cells from dying an improve blood flow, but difficult to administer.
Rats treated with the xenon-filled bubbles had smaller areas of brain damage than untreated animals.
In another piece of research, bubbles filled with a drug used to break down clots, were used to treat people who had strokes.
The technique eased the passage of the drug to the brain, speeding up the restoration of the blood flow to the brain.
But not without a cost - two of the patients given the highest dosage of the ''bubble drug'' in combination with ultrasound started haemorrhaging and died.