Researchers have found the gateway to delivering drugs into the brain!

The blood-brain barrier protects our brain and isolates it from the general blood circulation. It prevents the entry of toxic molecules into the central nervous system, but also of certain remedies which would however be useful in the treatment of neurological diseases. A team would have found a way to circumvent it and deliver drugs directly to the brain.

The brain consists of several billion neurons. These vulnerable cells, which are essential for the proper functioning of the body, benefit from a protective environment thanks to brain and the cranium. The blood-brain barrier represents a chemical and structural boundary that separates the brain from the rest of the body. It controls the elements capable of entering the cerebral compartment; it has a filtering role to prevent molecules toxins do not enter the brain.

In this logic, it prevents the passage of certain drugs. This constitutes an obstacle to the treatment of neurological diseases. Researchers at Yale University in the United States have looked into the matter: they have developed a system allowing the blood-brain barrier to be opened for a few hours at a time chosen in advance in order to allow administration of drugs in the brain. Their work was published on March 4 in the prestigious journal Nature.

Permeabilize the barrier

This is the first time that a team has claimed to be able to temporarily permeabilize the blood-brain barrier to allow the treatment of brain pathologies. The Wnt signaling pathway is involved in the maintenance ofintegrity barrier between the brain and the rest of the body. The Unc5B receiver has the ability to control this pathway by keeping the barrier impermeable. To do this, he must be hooked to his ligand Netrin-1.

The authors performed experiments in adult mice with a functional blood-brain barrier. When Unc5B receptor expression is turned off, the barrier is open. When expression of the Unc5B receptor is turned on but its ligand Netrin-1 is absent, the barrier is also open.

An antibody to open the barrier on demand

The authors then developed a antibody capable of attaching to Netrin-1. When the Netrin-1 binding site to the Unc5B receptor is masked by a antibody, the barrier remains open. The developed antibody was injected into adult mice. The passage to the brain remains open until the antibody is eliminated by the body.

It is therefore a system which makes it possible to maintain the blood-brain barrier open transiently and reversible — time to administer medication — via injection of antibodies. This discovery could completely change the game in the management of diseases of the central nervous system such as Parkinson diseasemultiple sclerosis, Alzheimer’s disease where the brain cancers.