Delivering drugs to the brain remains a challenge due to the blood-brain barrier, a specialized endothelial layer that is highly selective in what it permits into the 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 allowing for new treatments for brain tumors and other conditions affecting the brain.
The method involves administering gold nanoparticles into the blood stream and then activating them using transcranial laser illumination to cause temporary openings in the tight junctions between endothelial cells that line the cerebral blood vessels. Once the nanoparticles are in place near the tight junctions, the researchers use a very rapid burst of laser light, which can penetrate the skull non-invasively, to ‘activate’ them, causing a small mechanical force to act on the tight junctions. This means that the barrier becomes permeable for a while, allowing the researchers to deliver different types of therapeutic into the brain.
So far, the UT Dallas team tested the system in its ability to deliver various therapeutics, including antibodies, gene therapies, and liposomes, suggesting that the technique is highly versatile.
“Approaches to increase blood-brain barrier [BBB] permeability are essential to advance therapeutics for central nervous system diseases,” said Xiaoqing Li, a researcher involved in the study, via a press release. “The action produces a tiny mechanical force that temporarily breaks the barrier open so a drug can enter the blood flow into the brain,”
So far, the UT Dallas team has shown that the technique does not appear to be harmful, and it allows them to deliver a variety of therapeutics. More studies will be necessary, but the novel technique may prove out to be very important in making new therapies available for brain conditions.
“We demonstrated that the BBB permeability can be modulated without significant disruption to the spontaneous vasomotion or the structure of the neurovascular unit,” said Dr. Qi Cai, another researcher involved in the study.
Study in Nano Letters: Reversibly Modulating the Blood–Brain Barrier by Laser Stimulation of Molecular-Targeted Nanoparticles