In a modern twist on Mary Poppins, scientists have found that just a spoonful of CBD helps the medicine go up — into the brain. A huge barrier for doctors who want to deliver drugs to the human brain is quite literally a physical obstacle: The blood-brain barrier, which primarily functions to protect the brain. It’s very good at its job, preventing most molecules in the bloodstream from getting to our brains — life-saving drugs included — but recent research in Molecular Pharmaceutics suggests that CBD could sneak past the body’s natural defense systems.
In a paper published March 13, scientists demonstrated that attaching drug-carrying nanocapsules to CBD — that is, cannabidiol, the minimally psychoactive chemical found in cannabis and hemp — allowed them to slip them past the blood-brain barrier.
The researchers, from Complutense University of Madrid and The Open University in the UK, performed their experiments both in a lab model of the blood-brain barrier and in real mice, showing that their technique was much more effective at penetrating the blood-brain barrier than existing methods. It’s promising for doctors trying to treat diseases of the central nervous system, as the blood-brain barrier has so far proven to be an extremely challenging obstacle to successful drug delivery.
Lipid nanocapsules are drug-loaded nanoparticles that have become popular in cancer treatment for delivering chemotherapy drugs into patients’ bloodstreams. They have no problem reaching most organs in the human body, but the blood-brain barrier leaves the brain off-limits, making it difficult to treat brain tumors or multiple sclerosis.
This project may change all that.
The team built lipid nanocapsules, but they then “decorated” twhem ith CBD molecules. Their first experiment tested whether these CBD-decorated nanocapsules could get through a lab model of the human blood-brain barrier made of the same type of cells that constitute the real thing. After this test showed that they were on the right track, they then injected the nanocapsules into mice.
In the mice, they observed that when the lipid nanocapsules were decorated with CBD, 2.5 times more of them reached the mice’s brains than when nanocapsules were injected by themselves. This improvement indicates that they’re onto something.
The researchers report that this technique is six times more effective at crossing the blood-brain barrier than G-Technology, a similar type of nanoparticle delivery system designed to evade the blood-brain barrier that is currently undergoing clinical trials.
The researchers aren’t totally sure why CBD is allowed to pass the blood-brain barrier, but they suspect it has to do with the human body’s endocannabinoid system. This system of neurotransmitters and receptors is involved in all sorts of biological processes, including appetite, mood, and memory. Since the body is well-accustomed to letting its naturally occurring endocannabinoids through the blood-brain barrier, it would make sense that plant-based cannabinoids like CBD would be allowed to slip through — even if they’re bringing along a plus-one.
Obviously these results need to be validated further in animal and — eventually — human trials, but this paper suggests that treating brain tumors and multiple sclerosis with drugs may not be as much of a medical fantasy as it once was.
Abstract: Diseases affecting the central nervous system (CNS) should be regarded as a major health challenge due to the current lack of effective treatments given the hindrance to brain drug delivery imposed by the blood–brain barrier (BBB). Since efficient brain drug delivery should not solely rely on passive targeting, active targeting of nanomedicines into the CNS is being explored. The present study is devoted to the development of lipid nanocapsules (LNCs) decorated with nonpsychotropic cannabinoids as pioneering nonimmunogenic brain-targeting molecules and to the evaluation of their brain-targeting ability both in vitro and in vivo. Noticeably, both the permeability experiments across the hCMEC/D3 cell-based in vitro BBB model and the biodistribution experiments in mice consistently demonstrated that the highest brain-targeting ability was achieved with the smallest-sized cannabinoid-decorated LNCs. Importantly, the enhancement in brain targeting achieved with the conjugation of cannabidiol to LNCs outperformed by 6-fold the enhancement observed for the G-Technology (the main brain active strategy that has already entered clinical trials for the treatment of CNS diseases). As the transport efficiency across the BBB certainly determines the efficacy of the treatments for brain disorders, small cannabinoid-decorated LNCs represent auspicious platforms for the design and development of novel therapies for CNS diseases.