Crossing the Blood-Brain Barrier Using Lasers and Gold Nanoparticles

Delivering drugs to the brain remains a challenge because of the blood-brain barrier, a specialized endothelial layer that is highly selective in allowing the interior of neural tissue beyond. At the University of Texas at Dallas, researchers have developed a technique that allows therapeutics to cross the blood-brain barrier, potentially enabling new treatments for brain tumors and other conditions that affect the brain.

The method involves delivering gold nanoparticles into the bloodstream and then activating them using transcranial laser illumination to cause temporary openings at the tight junctions between endothelial cells that line brain blood vessels. Once the nanoparticles are in place near the tight junctions, the researchers use a very fast burst of laser light, which can non-invasively penetrate the skull, to ‘activate’ them, causing a small mechanical force to act on the tight junctions. This means that the barrier becomes permeable for a time, allowing researchers to deliver different types of therapies in the brain.

So far, the UT Dallas team tested the system for its ability to deliver various therapies, including antibodies, gene therapies, and liposomes, suggesting that the technique is highly versatile.

“Approaches to Increase the Blood Brain Barrier [BBB] patency is essential to advance the therapeutics of central nervous system diseases, “said Xiaoqing Li, a researcher involved in the study, through a press release. “The action produces a small mechanical force that temporarily breaks the barrier so that a drug can enter the bloodstream of the brain.”

So far, the UT Dallas team has shown that the technique does not appear to be harmful and allows them to offer a variety of therapies. More studies will be needed, but the new technique may prove very important in making new therapies available for brain conditions.

“We show that the permeability of the BBB can be modulated without significant disruption of spontaneous vasomotion or the structure of the neurovascular unit,” said Dr. Qi Cai, another researcher involved in the study.

To study in Nano letters: Reversible modulation of the blood-brain barrier by laser stimulation of nanoparticles directed at molecules

Via: University of Texas at Dallas

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