Nanotechnology helps CBD relieve pain from its source

Summary: A new study shows that CBD administered through a nanomicelle system can cross the blood-brain barrier and produce rapid relief from neuropathic pain. The formulation, called CBD-IN, helped the mice within 30 minutes and avoided the motor and cognitive side effects often seen with conventional painkillers.

Brain mapping revealed that CBD-IN silences overactive pain circuits only where abnormalities exist, without affecting healthy neurons. These findings suggest a new avenue for precise pain treatment using CBD without the risk of “high” or dependence associated with other cannabinoids.

Key facts

Targeted Relief: CBD-IN calmed only the abnormally active pain circuits, leaving healthy neurons unchanged. Improved delivery: Nanomicelles allowed CBD to efficiently cross the blood-brain barrier, overcoming a major limitation of standard CBD. No side effects: Mice showed strong pain relief without impairment of memory, balance or movement.

Source: University of Rochester

Turning to a CBD-infused lotion or oil may seem like a low-risk way to find pain relief, but little is actually known about the impact CBD has on the nervous system.

Over the past decade, the use of cannabis products for pain treatment has increased, in part because Congress signed a law in 2018 that removed hemp from the federal Controlled Substances Act, thereby legalizing hemp-derived CBD.

Today, it is most commonly found in oil form, as well as in lotions and cosmetics, and it is widely accepted that CBD does not cause a “high.” However, what CBD does in the human body and brain is not well understood.

Currently, the Food and Drug Administration has only approved CBD as an adjunct treatment for certain forms of epilepsy and is not recommended for use during pregnancy.

“We need to understand more about this compound, what mechanisms it interacts with in the brain, its impact on the body, and whether it is a potentially safer solution to treating the chronic pain epidemic,” said Kuan Hong Wang, PhD, professor of Neuroscience and member of the Del Monte Institute for Neuroscience at the University of Rochester, whose laboratory, in collaboration with researchers at Harvard Medical School and Boston Children’s Hospital, recently found that in mice, they could effectively deliver CBD to the brain to relieve neuropathic pain without adverse side effects.

This research was published today in the journal Cell Chemical Biology.

Design a delivery method

The first obstacle the researchers had to overcome was the blood-brain barrier. This part of our anatomy does an incredible job of keeping our brain healthy, as it essentially acts as a protective force field around the brain. Because of this barrier and the fact that CBD does not dissolve well in water, very little CBD reaches the brain when taken in its regular oil form.

Wang Laboratory scientist Jingyu Feng, PhD, and first author of the study, helped develop the delivery mechanism: inclusion complex-enhanced nanomicelle formulation, or CBD-IN. CBD-IN is a method that encapsulates CBD molecules within nanomicelles or water-soluble spheres that are considered safe in foods and medicines.

Researchers found that when CBD-IN was administered to mice, it provided pain relief within 30 minutes and without any of the common adverse side effects, such as loss of movement, balance or memory, that often occur when taking conventional pain relievers. “The pain relief also lasted through repeated use,” Feng said. “We didn’t see its effect disappear over time.”

Impact on the brain

Using genetic mapping and imaging tools, researchers revealed that when mice ingest CBD-IN, it calms overactive nerve circuits in areas of the brain and spinal cord responsible for sensing touch and pain. This calming effect only occurs when there is abnormal activation, such as after a nerve injury. Importantly, CBD-IN does not affect healthy neurons.

The researchers were surprised to discover that the analgesic effect did not depend on the typical cannabinoid receptors (CB1 and CB2) that THC and other cannabis compounds target in the body.

“Instead, CBD-IN appears to influence broader electrical and calcium signaling in nerve cells, offering a new way to control nervous hyperactivity without triggering the ‘high’ or dependence risks associated with traditional cannabinoids or opioids,” Feng said.

“The broader implication of this research is that nanotechnology can make natural compounds like CBD more effective and precise,” said Wang, co-senior author of this research.

“By improving brain management and focusing solely on disease-related neuronal hyperactivity, this strategy could open new doors for the treatment of chronic pain and possibly other neurological disorders, such as epilepsy or neurodegenerative diseases, where abnormal nerve activity plays a central role.”

This research was a collaboration between the University of Rochester, Harvard Medical School, and Boston Children’s Hospital. Other authors include Jessica Page, PhD, and Leeyup Chung, PhD, both co-authors, and Zhigang He, PhD, co-senior author, of Harvard Medical School. The research was supported by the National Institutes of Health and the Del Monte Institute for Neuroscience.

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About this research news on pain and neuropharmacology

Author: Kelsie Smith Hayduk
Source: University of Rochester
Contact: Kelsie Smith Hayduk – University of Rochester
Image: Image is credited to Neuroscience News.

Original research: findings to appear in Cell Chemical Biology