Botox has been approved for use to treat migraines for several years – now researchers are looking into a compound that broaden its use to other types of chronic pain.
Researchers in London and Toronto report that a botulinum molecule reassembled with an opioid called dermophin to make Derm-Bot which is giving long-lasting pain relief in mice without adverse effects.
For the study, published in Science Translational Medicine, Researchers from University College, London, the University of Sheffield and the Hospital for Sick Children in Toronto are finding that when they target neurons in the spinal cords of mice, pain signals can be silenced. Key neurons in the spinal cord are targets for pain management as they directly ‘sense’ pain and send this information to the brain.
“Injected into the spine, Derm-BOT relieves chronic pain – such as that caused by nerve damage – and avoids the adverse events of tolerance and addiction often associated with repeated opioid drug use,” explained co-corresponding author, Professor Steve Hunt of UCL.
“It doesn’t affect muscles like the botulinum toxin used to reduce wrinkles but it does block nerve pain for up to four months without affecting normal pain responses. It really could revolutionize how chronic pain is treated if we can translate it into clinic, removing the need for daily opioid intake.”
Opioids like morphine and fentanyl are considered to be the gold standard for pain relief but there is debated evidence that their long-term use is effective in treating chronic pain.
Previous studies in rats and companion dogs show that precise injections of tiny amounts of toxic substances, such as ‘substance P-saporin’, into the spine kill neurons responsible for crippling, chronic pain. This approach relies on an analogue of ricin which is difficult to manufacture to clinical standards and clinicians are resistant to irreversibly kill nerve cells.
In contrast, researchers believe that Derm-BOT is safe to manufacture, is non-toxic and does not kill neurons.
“We needed to find the best pain targeting molecular parts to direct the botulinum silencing ‘warhead’ to the pain-controlling system in the spine. For this, we developed a molecular Lego system which allows us to link the botulinum ‘warhead’ to a navigation molecule, in this case, the strong opioid called dermorphin, allowing the creation of widely desired long-lasting pain killers without the side effects of opioids,” said co-corresponding author Professor Bazbek Davletov from the Department of Biomedical Science at the University of Sheffield.