The brain is a vitally important organ. It is the control center for thoughts, personality, and emotion. The brain also aids in the control of body temperature, heart rate, respiratory rate, and many other physiologically important mechanisms. Due to this, the brain has developed many defenses against foreign invaders. Of these, the blood-brain barrier is one of the most important.
The blood-brain barrier arises from outgrowths of specific cells that cover blood vessels in the brain. This shielding prevents waste products in the blood from entering the brain and causing damage. It also helps prevent environmental toxins that may enter the body from harming the brain. In nearly every case, the blood-brain barrier is helpful and needed, but it can be a bit of a nuisance when treating brain disorders since many drugs are unable to cross the barrier.
Cannabidiol (CBD) is a compound found in marijuana plants, but it is not a psychoactive drug. The psychoactive ingredient present in marijuana is tetrahydrocannabinol (THC), but it is not the substance in question here. CBD can be extracted from the plants and separated from THC. From here, it can be manufactured into an oil that can be used for a variety of situations. Another interesting feature of CBD is its ability to cross the blood-brain barrier, implicating it in the treatment of brain disorders.
Rather than relying on drug precursors that can cross the barrier and then be metabolized into the active drug, pharmaceutical research is beginning to look at ways CBD can be used to place active drugs directly into the brain. Specifically, the CBD is being slightly altered so that it can be bound in some way to the treatment drug, allowing the blood-brain barrier to be penetrated. It is important to keep in mind that the research regarding CBD is in its infancy, and much more needs to be done before the technique to be described can be routinely employed.
There are many biological molecules with different properties, and this diversity is what ultimately gives rise to the complexity of life. Lipids are a particularly interesting class because they can travel in both water and other lipids depending on the make-up of the compound. Chemists can create spherical lipid nanoparticles that contain the treatment drug dissolved in the core. The outside of the nanoparticle can then be edited to change its functionality.
After the nanoparticle with the drug is assembled, the researchers can bond CBD to the outside of the nanoparticle. Once it approaches the blood-brain barrier, the CBD allows the whole particle to move across the barrier. Depending on how the nanoparticle was built, it may be metabolized once at its destination or it may be degraded over time. Regardless, the treatment drug is released directly in the brain and able to do its work without needing to cross the blood-brain barrier alone.
Currently, the research surrounding this method of surpassing the blood-brain barrier is promising. Groups treated with CBD have a much higher concentration of the treatment drug in the brain than those without CBD, but this research has yet to move into serious human studies. Soon though, CBD seems to be a competitive contender in helping physicians treat brain disorders like Parkinson's and epilepsy.