Nanoparticle Drug Delivery Offers Nonopioid Treatment for Chronic Pain
Researchers have taken aprepitant — a U.S. Food and Drug Administration-approved drug that previously failed in clinical trials for pain — and repackaged it using a novel, nano-based technology to deliver the drug into specific compartments of nerve cells.
Researchers have taken aprepitant — a U.S. Food and Drug Administration-approved drug that previously failed in clinical trials for pain — and repackaged it using a novel, nano-based technology to deliver the drug into specific compartments of nerve cells. The investigators report that nanoparticle-delivered aprepitant treated pain in mice and rats more effectively and for longer duration than conventional therapies, including opioids.
In the study published in Nature Nanotechnology, an international team led by Nigel W. Bunnett, PhD, chair of the Department of Basic Science and Craniofacial Biology at New York University College of Dentistry, focused on a G protein-coupled receptor called the neurokinin 1 receptor.
Investigators developed the novel treatment after discovering most pain drugs target receptors (neurokinin receptor antagonists) at the surface of neurons, when they should be targeting receptors within the neuron. Initially thought to function at the surface of nerve cells, activated receptors function for prolonged periods within a cell’s endosome. This activity drives pain.
Working with a team that included researchers from Monash University, Columbia University, and the University of Santiago in Chile, Bunnett and colleagues developed a method that allowed nanoparticles to release aprepitant in endosomes containing the neurokinin 1 receptor, effectively blocking function in the receptor signaling pain.
The animals that received the drug via nanoparticle encapsulation experienced three to five hours of pain relief, whereas subjects that were given conventional antagonists or opioids were pain-free for an hour. Further trials are needed to determine if the treatment model is effective in humans, but Bunnett believes this approach could be used in dentistry to treat oral and facial pain. The team is exploring ways to block pathways and encapsulate several types of drugs into nanoparticles to effectively treat chronic pain without opioids.
From Decisions in Dentistry. February 2020;6(2):11.